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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.1014 | Jassem Al-Alawi Mr | Jassem H. Al-Alawi, Wojtek J. Zakrzewski | Scattering of Topological Solitons on Barriers and Holes in Two \lambda
\phi^4 Models | 11 pages, 12 postscript figures | J.Phys.A40:11319-11332,2007 | 10.1088/1751-8113/40/37/009 | null | hep-th | null | We present results of our studies of various scattering properties of
topological solitons on obstructions in the form of holes and barriers in 1+1
dimensions. Our results are based on two models involving a \phi^4 potential.
The obstructions are characterised by a potential parameter, \lambda which has
a non-zero value in a certain region of space and zero elsewhere. In the first
model the potential parameter is included in the potential and in the second
model the potential parameter is included in the metric. Our results are based
on numerical simulations and analytical considerations.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 14:53:54 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Al-Alawi",
"Jassem H.",
""
],
[
"Zakrzewski",
"Wojtek J.",
""
]
] |
0706.1015 | Charalampos Bogdanos | C. Bogdanos, A. Dimitriadis and K. Tamvakis | Synergistic Gravity and the Role of Resonances in GRS-Inspired
Braneworlds | 18 pages, 3 figures, added 1 figure, revised version as published in
Class. Quant. Grav | Class.Quant.Grav.25:045008,2008 | 10.1088/0264-9381/25/4/045008 | null | hep-th gr-qc hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider 5D braneworld models of quasi-localized gravity in which 4D
gravity is reproduced at intermediate scales while the extra dimension opens up
at both the very short and the very long distances, where the geometry is flat.
Our main interest is the interplay between the zero mode of these models,
whenever a normalizable zero mode exists, and the effects of zero energy
graviton resonant modes coming from the contributions of massive KK modes. We
first consider a compactified version of the GRS model and find that
quasi-localized gravity is characterized by a scale for which both the
resonance and the zero mode have significant contribution to 4D gravity. Above
this scale, gravity is primarily mediated by the zero mode, while the resonance
gives only minor corrections. Next, we consider an asymmetric version of the
standard non-compact GRS model, characterized by different cosmological
constants on each AdS side. We show that a resonance is present but the
asymmetry, through the form of the localizing potential, can weaken it,
resulting in a shorter lifetime and, thus, in a shorter distance scale for 4D
gravity. As a third model exhibiting quasi-localization, we consider a version
of the GRS model in which the central positive tension brane has been replaced
by a configuration of a scalar field propagating in the bulk.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 14:54:10 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Mar 2009 23:19:05 GMT"
}
] | 2009-03-17T00:00:00 | [
[
"Bogdanos",
"C.",
""
],
[
"Dimitriadis",
"A.",
""
],
[
"Tamvakis",
"K.",
""
]
] |
0706.1016 | Emmanuel Guitter | J. Bouttier, M. Bowick, E. Guitter and M. Jeng | Vacancy localization in the square dimer model | 35 pages, 24 figures. Improved version with one added figure (figure
9), a shift s->s+1 in the definition of the tree size, and minor corrections | Phys. Rev. E 76, 041140 (2007) | 10.1103/PhysRevE.76.041140 | null | cond-mat.stat-mech | null | We study the classical dimer model on a square lattice with a single vacancy
by developing a graph-theoretic classification of the set of all configurations
which extends the spanning tree formulation of close-packed dimers. With this
formalism, we can address the question of the possible motion of the vacancy
induced by dimer slidings. We find a probability 57/4-10Sqrt[2] for the vacancy
to be strictly jammed in an infinite system. More generally, the size
distribution of the domain accessible to the vacancy is characterized by a
power law decay with exponent 9/8. On a finite system, the probability that a
vacancy in the bulk can reach the boundary falls off as a power law of the
system size with exponent 1/4. The resultant weak localization of vacancies
still allows for unbounded diffusion, characterized by a diffusion exponent
that we relate to that of diffusion on spanning trees. We also implement
numerical simulations of the model with both free and periodic boundary
conditions.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:01:03 GMT"
},
{
"version": "v2",
"created": "Wed, 31 Oct 2007 09:29:41 GMT"
}
] | 2007-10-31T00:00:00 | [
[
"Bouttier",
"J.",
""
],
[
"Bowick",
"M.",
""
],
[
"Guitter",
"E.",
""
],
[
"Jeng",
"M.",
""
]
] |
0706.1017 | Yves-Henri Sanejouand | Brice Juanico, Yves-Henri Sanejouand, Francesco Piazza, Paolo de los
Rios | Discrete breathers in nonlinear network models of proteins | 4 pages, 5 figures. Minor changes | Physical review letters vol. 99, 238104 (2007) | 10.1103/PhysRevLett.99.238104 | null | q-bio.BM | null | We introduce a topology-based nonlinear network model of protein dynamics
with the aim of investigating the interplay of spatial disorder and
nonlinearity. We show that spontaneous localization of energy occurs
generically and is a site-dependent process. Localized modes of nonlinear
origin form spontaneously in the stiffest parts of the structure and display
site-dependent activation energies. Our results provide a straightforward way
for understanding the recently discovered link between protein local stiffness
and enzymatic activity. They strongly suggest that nonlinear phenomena may play
an important role in enzyme function, allowing for energy storage during the
catalytic process.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:01:29 GMT"
},
{
"version": "v2",
"created": "Thu, 8 Nov 2007 18:07:57 GMT"
},
{
"version": "v3",
"created": "Fri, 21 Dec 2007 18:23:10 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Juanico",
"Brice",
""
],
[
"Sanejouand",
"Yves-Henri",
""
],
[
"Piazza",
"Francesco",
""
],
[
"Rios",
"Paolo de los",
""
]
] |
0706.1018 | Claudio Cazorla | C. Cazorla, M. J. Gillan, S. Taioli and D. Alf\`e | Melting curve and Hugoniot of molybdenum up to 400 GPa by ab initio
simulations | 8 pages, 6 figures | null | 10.1088/1742-6596/121/1/012009 | null | cond-mat.mtrl-sci cond-mat.str-el | null | We report ab initio calculations of the melting curve and Hugoniot of
molybdenum for the pressure range 0-400 GPa, using density functional theory
(DFT) in the projector augmented wave (PAW) implementation. We use the
``reference coexistence'' technique to overcome uncertainties inherent in
earlier DFT calculations of the melting curve of Mo. Our calculated melting
curve agrees well with experiment at ambient pressure and is consistent with
shock data at high pressure, but does not agree with the high pressure melting
curve from static compression experiments. Our calculated P(V) and T(P)
Hugoniot relations agree well with shock measurements. We use calculations of
phonon dispersion relations as a function of pressure to eliminate some
possible interpretations of the solid-solid phase transition observed in shock
experiments on Mo.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:02:32 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cazorla",
"C.",
""
],
[
"Gillan",
"M. J.",
""
],
[
"Taioli",
"S.",
""
],
[
"Alfè",
"D.",
""
]
] |
0706.1019 | Flavio Garcia | Flavio D. Garcia, Peter van Rossum, and Ana Sokolova | Probabilistic Anonymity and Admissible Schedulers | null | null | null | null | cs.CR | null | When studying safety properties of (formal) protocol models, it is customary
to view the scheduler as an adversary: an entity trying to falsify the safety
property. We show that in the context of security protocols, and in particular
of anonymizing protocols, this gives the adversary too much power; for
instance, the contents of encrypted messages and internal computations by the
parties should be considered invisible to the adversary.
We restrict the class of schedulers to a class of admissible schedulers which
better model adversarial behaviour. These admissible schedulers base their
decision solely on the past behaviour of the system that is visible to the
adversary.
Using this, we propose a definition of anonymity: for all admissible
schedulers the identity of the users and the observations of the adversary are
independent stochastic variables. We also develop a proof technique for typical
cases that can be used to proof anonymity: a system is anonymous if it is
possible to `exchange' the behaviour of two users without the adversary
`noticing'.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:17:52 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Garcia",
"Flavio D.",
""
],
[
"van Rossum",
"Peter",
""
],
[
"Sokolova",
"Ana",
""
]
] |
0706.1020 | Gesualdo Delfino | Gesualdo Delfino, Paolo Grinza | Confinement in the q-state Potts field theory | 21 pages, 8 figures. v2: references added | Nucl.Phys.B791:265-283,2008 | 10.1016/j.nuclphysb.2007.09.003 | null | hep-th cond-mat.stat-mech | null | The q-state Potts field theory describes the universality class associated to
the spontaneous breaking of the permutation symmetry of q colors. In two
dimensions it is defined up to q=4 and exhibits duality and integrability away
from critical temperature in absence of magnetic field. We show how, when a
magnetic field is switched on, it provides the simplest model of confinement
allowing for both mesons and baryons. Deconfined quarks (kinks) exist in a
phase bounded by a first order transition on one side, and a second order
transition on the other. The evolution of the mass spectrum with temperature
and magnetic field is discussed.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:22:04 GMT"
},
{
"version": "v2",
"created": "Tue, 19 Jun 2007 09:24:39 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Delfino",
"Gesualdo",
""
],
[
"Grinza",
"Paolo",
""
]
] |
0706.1021 | Xiang Tang | G. Felder and X. Tang | Equivariant Lefschetz number of differential operators | 16 pages | null | null | null | math.QA math.AG | null | Let $G$ be a compact Lie group acting on a compact complex manifold $M$. We
prove a trace density formula for the $G$-Lefschetz number of a differential
operator on $M$. We generalize Engeli and Felder's recent results to orbifolds.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:22:09 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Felder",
"G.",
""
],
[
"Tang",
"X.",
""
]
] |
0706.1022 | Guillaume Alain | Guillaume Alain | Simultaneous approximation of a real number by all conjugates of an
algebraic number | 7 pages | Acta Arith. 127 (2007), 63-70 | 10.4064/aa127-1-5 | null | math.NT | null | Using a method of H. Davenport and W. M. Schmidt, we show that, for each
positive integer n, the ratio 2/n is the optimal exponent of simultaneous
approximation to real irrational numbers 1) by all conjugates of algebraic
numbers of degree n, and 2) by all but one conjugates of algebraic integers of
degree n+1.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:39:18 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Alain",
"Guillaume",
""
]
] |
0706.1023 | Kartick Tarafder Mr. | Kartick Tarafder, Atisdipankar Chakrabarti, Subhradip Ghosh, Biplab
Sanyal, Olle Eriksson, Abhijit Mookerjee | Electronic, magnetic and optical properties of random Fe-Cr alloys | 13 pages 11 figures | null | null | null | cond-mat.dis-nn | null | In this communication we have studied the electronic structure, magnetic and
optical properties of bcc \fecr alloys in the ferromagnetic phase. We have used
the augmented space recursion technique coupled with tight-binding linearized
muffin-tin orbital technique (TB-LMTO-ASR) as well as the coherent-potential
approximation based on the Korringa-Kohn-Rostocker method (KKR-CPA). Also the
plane wave projector augmented wave (PAW) method has been used with the
disorder simulated by the special quasi-random structure method f or
configuration averaging (SQS). This was to provide a comparison between the
different methods in common use for random alloys. Moreover, using the
self-consistent potential parameters from TB-LMTO-ASR ca lculations we obtained
the spin resolved optical conductivity using the generalized recursion
technique proposed by M\"uller and Vishwanathan.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:31:20 GMT"
},
{
"version": "v2",
"created": "Tue, 12 Jun 2007 08:40:16 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Tarafder",
"Kartick",
""
],
[
"Chakrabarti",
"Atisdipankar",
""
],
[
"Ghosh",
"Subhradip",
""
],
[
"Sanyal",
"Biplab",
""
],
[
"Eriksson",
"Olle",
""
],
[
"Mookerjee",
"Abhijit",
""
]
] |
0706.1024 | Philippe Brax | Ph. Brax, C. van de Bruck and A. C. Davis | A Chameleon Primer | 8 pages, to appear in the proceedings of the Rencontres de Moriond
2007 "Experimental Gravity and Gravitational Waves", La Thuile, 11-18 March
2007 | null | null | null | astro-ph | null | We review some of the properties of chameleon theories. Chameleon fields are
gravitationally coupled to matter and evade gravitational tests thanks to two
fundamental properties. The first one is the density dependence of the
chameleon mass. In most cases, in a dense environment, chameleons are massive
enough to induce a short ranged fifth force. In other cases, non-linear effects
imply the existence of a thin shell effect shielding compact bodies from each
other and leading to an irrelevant fifth force. We also mention how a natural
extension of chameleon theories can play a role to solve the PVLAS versus CAST
discrepancy.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:31:31 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Sep 2007 14:09:22 GMT"
}
] | 2007-09-13T00:00:00 | [
[
"Brax",
"Ph.",
""
],
[
"van de Bruck",
"C.",
""
],
[
"Davis",
"A. C.",
""
]
] |
0706.1025 | Loriano Bonora | L. Bonora, C. Maccaferri, R. J. Scherer Santos, D. D. Tolla | Ghost story. I. Wedge states in the oscillator formalism | 53 pages, latex, subsection 2.5 and section 6 enlarged, to appear in
JHEP | JHEP 0709:061,2007 | 10.1088/1126-6708/2007/09/061 | SISSA/34/2007/EP | hep-th | null | This paper is primarily devoted to the ghost wedge states in string field
theory formulated with the oscillator formalism. Our aim is to prove, using
such formalism, that the wedge states can be expressed as
|n> = exp[{2-n}/2 ({\cal L}_0+{\cal L}_0^\daggert)]|0>, separately in the
matter and ghost sector. This relation is crucial for instance in the proof of
Schnabl's solution. We start from the exponentials in the rhs and wish to prove
that they take precisely the form of wedge states. As a guideline we first
re-demonstrate this relation for the matter part. Then we turn to the ghosts.
On the way we face the problem of `diagonalizing' infinite rectangular
matrices. We manage to give a meaning to such an operation and to prove that
the eigenvalues we obtain satisfy the recursion relations of the wedge states.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:38:16 GMT"
},
{
"version": "v2",
"created": "Tue, 19 Jun 2007 15:27:51 GMT"
},
{
"version": "v3",
"created": "Thu, 6 Sep 2007 16:16:42 GMT"
}
] | 2009-04-03T00:00:00 | [
[
"Bonora",
"L.",
""
],
[
"Maccaferri",
"C.",
""
],
[
"Santos",
"R. J. Scherer",
""
],
[
"Tolla",
"D. D.",
""
]
] |
0706.1026 | Dmitri Kharzeev | D. Kharzeev and A. Zhitnitsky | Charge separation induced by P-odd bubbles in QCD matter | 9 pages, 1 figure; extended discussion of cosmological and
astrophysical implications; final version to appear in Nuclear Physics A | Nucl.Phys.A797:67-79,2007 | 10.1016/j.nuclphysa.2007.10.001 | BNL-NT-07/24 | hep-ph astro-ph hep-th nucl-ex nucl-th | null | We examine the recent suggestion that P- and CP-odd effects in QCD matter can
induce electric charge asymmetry with respect to reaction plane in relativistic
heavy ion collisions. General arguments are given which confirm that the
angular momentum of QCD matter in the presence of non-zero topological charge
should induce an electric field aligned along the axis of the angular momentum.
A simple formula relating the magnitude of charge asymmetry to the angular
momentum and topological charge is derived. The expected asymmetry is amenable
to experimental observation at RHIC and LHC; we discuss the recent preliminary
STAR result in light of our findings.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:38:18 GMT"
},
{
"version": "v2",
"created": "Mon, 1 Oct 2007 18:08:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kharzeev",
"D.",
""
],
[
"Zhitnitsky",
"A.",
""
]
] |
0706.1027 | Mikhail Kozlov | M G Kozlov, G F Gribakin, and F J Currell | Parity nonconservation in dielectronic recombination of multiply charged
ions | Talk at International Workshop on Atomic & Nuclear Cross Disciplinary
Physics, Shanghai, June 2006 | JOURNAL OF FUDAN UNIVERSITY(NATURAL SCIENCE) v. 46, p. 50 (2007) | null | null | physics.atom-ph | null | We discuss a parity nonconserving (PNC) asymmetry in the cross section of
dielectronic recombination of polarized electrons on multiply charged ions with
Z>40. This effect is strongly enhanced for close doubly-excited states of
opposite parity in the intermediate compound ion. Such states are known for
He-like ions. However, these levels have large energy and large radiative
widths which hampers observation of the PNC asymmetry. We argue that
accidentally degenerate states of the more complex ions may be more suitable
for the corresponding experiment.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:45:04 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Kozlov",
"M G",
""
],
[
"Gribakin",
"G F",
""
],
[
"Currell",
"F J",
""
]
] |
0706.1028 | Gerard Weisbuch | Tanya Ara\'ujo, G\'erard Weisbuch | Hiking the hypercube: producers and consumers | null | null | null | null | q-fin.GN physics.soc-ph | null | We study the dynamics of co-evolution of producers and customers described by
bit-strings representing individual traits. Individual ''size-like'' properties
are controlled by binary encounters which outcome depends upon a recognition
process. Depending upon the parameter set-up, mutual selection of producers and
customers results in different types of attractors, either an exclusive niches
regime or a competition regime.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:47:16 GMT"
}
] | 2008-12-02T00:00:00 | [
[
"Araújo",
"Tanya",
""
],
[
"Weisbuch",
"Gérard",
""
]
] |
0706.1029 | Marie-No\"elle C\'el\'erier | Marie-No\"elle C\'el\'erier (Observatoire de Paris-Meudon) | Inhomogeneities in the Universe and the Fitting Problem | 7 pages, to be published in the Proceedings of the XIXth Rencontres
de Blois, Matter and energy in the Universe, Blois, France, May 2007,
modified comments, minor changes | null | null | null | astro-ph | null | Observational cosmology provides us with a large number of high precision
data which are used to derive models trying to reproduce ``on the mean'' our
observable patch of the Universe. Most of these attempts are achieved in the
framework of a Friedmann-Lema\^itre cosmology where large scale homogeneity is
assumed. However, we know, from the observation of structures at increasing
scales, that these models are only approximations of a smoothed or averaged
inhomogeneous underlying patern. Anyhow, when modelling the Universe, the usual
method is to use continuous functions representing the kinematical scalars of
the velocity field, implicitly assuming that they represent volume averages of
the corresponding fine-scale inhomogeneous quantities, then put them into the
Einstein equations which are solved to give the model and its dependance upon a
number of parameters arbitrarily defined. In General Relativity, such a method
is very much involved since the equations which determine the metric tensor and
the quantities calculated from it are highly nonlinear. The question raised by
the method consisting of determining the parameters of an a priori assumed FLRW
model from observational data is the ``fitting problem'' brought to general
attention by Ellis and Stoeger in the 80's. This problem has recently
experienced a reniewed attention due to the amount of available data and the
increase of the minimum scale at which homogeneity can be assumed. We propose a
discussion of this issue in the light of the latest developments of
observational and theoretical cosmology.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:54:57 GMT"
},
{
"version": "v2",
"created": "Fri, 29 Jun 2007 15:42:57 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Célérier",
"Marie-Noëlle",
"",
"Observatoire de Paris-Meudon"
]
] |
0706.1030 | Yasuaki Hikida | Yasuaki Hikida and Volker Schomerus | H^+_3 WZNW model from Liouville field theory | 33 pages, no figure, minor changes, several equations corrected | JHEP 0710:064,2007 | 10.1088/1126-6708/2007/10/064 | DESY 07-075 | hep-th | null | There exists an intriguing relation between genus zero correlation functions
in the H^+_3 WZNW model and in Liouville field theory. We provide a path
integral derivation of the correspondence and then use our new approach to
generalize the relation to surfaces of arbitrary genus g. In particular we
determine the correlation functions of N primary fields in the WZNW model
explicitly through Liouville correlators with N+2g-2 additional insertions of
certain degenerate fields. The paper concludes with a list of interesting
further extensions and a few comments on the relation to the geometric
Langlands program.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:59:34 GMT"
},
{
"version": "v2",
"created": "Fri, 19 Oct 2007 14:20:29 GMT"
},
{
"version": "v3",
"created": "Mon, 14 Jan 2008 17:37:31 GMT"
}
] | 2009-04-03T00:00:00 | [
[
"Hikida",
"Yasuaki",
""
],
[
"Schomerus",
"Volker",
""
]
] |
0706.1031 | Simone Diverio | Simone Diverio | Differential Equations on Complex Projective Hypersurfaces of Low
Dimension | Final version, some minor changes according to referee's suggestions,
to appear in Compositio Mathematica | null | 10.1112/S0010437X07003478 | Roma01.math.AG | math.AG math.CV | null | Let $n=2,3,4,5$ and let $X$ be a smooth complex projective hypersurface of
$\mathbb P^{n+1}$. In this paper we find an effective lower bound for the
degree of $X$, such that every holomorphic entire curve in $X$ must satisfy an
algebraic differential equation of order $k=n=\dim X$, and also similar bounds
for order $k>n$. Moreover, for every integer $n\ge 2$, we show that there are
no such algebraic differential equations of order $k<n$ for a smooth
hypersurface in $\mathbb P^{n+1}$.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:58:57 GMT"
},
{
"version": "v2",
"created": "Mon, 11 Jun 2007 09:48:19 GMT"
},
{
"version": "v3",
"created": "Tue, 26 Feb 2008 17:37:04 GMT"
}
] | 2017-04-04T00:00:00 | [
[
"Diverio",
"Simone",
""
]
] |
0706.1032 | Hal Tasaki | Hal Tasaki | Two theorems that relate discrete stochastic processes to microscopic
mechanics | 4 pages, 2 figures | null | null | null | cond-mat.stat-mech | null | Starting from a classical mechanics of a ``colloid particle'' and $N$ ``water
molecules'', we study effective stochastic dynamics of the particle which jumps
between deep potential wells. We prove that the effective transition
probability satisfies (local) detailed balance condition. This enables us to
rigorously determine precise form of the transition probability when barrier
potentials have certain regularity and symmetry.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 15:59:36 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Tasaki",
"Hal",
""
]
] |
0706.1033 | Joachim Kock | Joachim Kock, Andr\'e Joyal, Michael Batanin, and Jean-Fran\c{c}ois
Mascari | Polynomial functors and opetopes | LaTeX, 54 pages, 75 texdraw figures. Accompanying opetope scripts in
Tcl hidden in tex source after \end{document} for the sake of archival --
also available from http://mat.uab.cat/~kock/cat/zoom.html . v2: substantial
expository improvements, following the advice from the referees. Final
version, to appear in Adv. Math | Adv. Math. 224 (2010), 2690-2737 | 10.1016/j.aim.2010.02.012 | null | math.QA math.CT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give an elementary and direct combinatorial definition of opetopes in
terms of trees, well-suited for graphical manipulation and explicit
computation. To relate our definition to the classical definition, we recast
the Baez-Dolan slice construction for operads in terms of polynomial monads:
our opetopes appear naturally as types for polynomial monads obtained by
iterating the Baez-Dolan construction, starting with the trivial monad. We show
that our notion of opetope agrees with Leinster's. Next we observe a suspension
operation for opetopes, and define a notion of stable opetopes. Stable opetopes
form a least fixpoint for the Baez-Dolan construction. A final section is
devoted to example computations, and indicates also how the calculus of
opetopes is well-suited for machine implementation.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:29:06 GMT"
},
{
"version": "v2",
"created": "Sun, 21 Feb 2010 00:33:30 GMT"
}
] | 2010-06-11T00:00:00 | [
[
"Kock",
"Joachim",
""
],
[
"Joyal",
"André",
""
],
[
"Batanin",
"Michael",
""
],
[
"Mascari",
"Jean-François",
""
]
] |
0706.1034 | Grigori Olshanski | Alexei Borodin and Grigori Olshanski | Infinite-dimensional diffusions as limits of random walks on partitions | AMSTex, 33 pages. Version 2: minor changes, typos corrected, to
appear in Prob. Theor. Rel. Fields | Prob. Theor. Rel. Fields 144 (2009), no. 1, 281-318 | 10.1007/s00440-008-0148-8 | Preprint Series of SFB 701, University of Bielefeld, #07-035 | math.PR math.RT | null | The present paper originated from our previous study of the problem of
harmonic analysis on the infinite symmetric group. This problem leads to a
family {P_z} of probability measures, the z-measures, which depend on the
complex parameter z. The z-measures live on the Thoma simplex, an
infinite-dimensional compact space which is a kind of dual object to the
infinite symmetric group. The aim of the paper is to introduce stochastic
dynamics related to the z-measures. Namely, we construct a family of diffusion
processes in the Toma simplex indexed by the same parameter z. Our diffusions
are obtained from certain Markov chains on partitions of natural numbers n in a
scaling limit as n goes to infinity. These Markov chains arise in a natural
way, due to the approximation of the infinite symmetric group by the increasing
chain of the finite symmetric groups. Each z-measure P_z serves as a unique
invariant distribution for the corresponding diffusion process, and the process
is ergodic with respect to P_z. Moreover, P_z is a symmetrizing measure, so
that the process is reversible. We describe the spectrum of its generator and
compute the associated (pre)Dirichlet form.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 16:25:27 GMT"
},
{
"version": "v2",
"created": "Sun, 24 Feb 2008 17:34:26 GMT"
}
] | 2009-02-15T00:00:00 | [
[
"Borodin",
"Alexei",
""
],
[
"Olshanski",
"Grigori",
""
]
] |
0706.1035 | Bruce Cohen I | Bruce I. Cohen, Andris M. Dimits, and William M. Nevins | Comment on "Electromagnetic Global Gyrokinetic Simulation of Shear
Alfven Wave Dynamics in Tokamak Plasmas" [Phys. Plasmas 14, 042503 (2007)] | 7 pages, Comment | null | null | UCRL-JRNL-230728 | physics.plasm-ph | null | This comment clarifies the relation of the research in a recently published
article [Phys. Plasmas 14, 042503 (2007)] to other prior publications
addressing the inclusion of electromagnetic and drift-kinetic electron physics
in gyrokinetic simulation, raises a concern related to the inclusion of kinetic
electrons in a system with magnetic shear, and discusses alternatives in the
face of an important limitation on the general applicability of the algorithm
described therein.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 16:26:01 GMT"
},
{
"version": "v2",
"created": "Fri, 26 Oct 2007 22:31:03 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Cohen",
"Bruce I.",
""
],
[
"Dimits",
"Andris M.",
""
],
[
"Nevins",
"William M.",
""
]
] |
0706.1036 | Irais Rubalcava Garcia | G.F. Torres del Castillo, I. Rubalcava Garcia | Transfer matrices for piecewise constant potentials | 10 pages | Rev. Mex. Fis. E, 52 (2006) 172 | null | null | physics.class-ph physics.gen-ph | null | By expressing the time-independent Schrodinger equation in one dimension as a
system of two first-order differential equations, the transfer matrix for a
rectangular potential barrier is obtained making use of the matrix exponential.
It is shown that the transfer matrix allows one to find the bound states and
the quasinormal modes. A similar treatment for the one-dimensional propagation
of electromagnetic waves in a homogeneous medium is also presented.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 16:47:28 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"del Castillo",
"G. F. Torres",
""
],
[
"Garcia",
"I. Rubalcava",
""
]
] |
0706.1037 | Oguz C. Durumeric | Oguz C. Durumeric | Local Structure of Ideal Shapes of Knots, II, Constant Curvature Case | 12 pages | null | null | null | math.GT math.DG | null | The thickness, NIR(K) of a knot or link K is defined to be the radius of the
largest solid tube one can put around the curve without any self intersections,
which is also known as the normal injectivity radius of K. For C^{1,1} curves
K, NIR(K)=min{(1/2)DCSC(K),(1/(supkappa(K))))}, where kappa(K) is the
generalized curvature, and the double critical self distance DCSD(K) is the
shortest length of the segments perpendicular to K at both end points. The
knots and links in ideal shapes (or tight knots or links) belong to the minima
of ropelength = length/thickness within a fixed isotopy class. In this article,
we prove that NIR(K)=(1/2)DCSC(K), for every relative minimum K of ropelength
in R^n for certain dimensions n, including n=3.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 16:46:51 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Durumeric",
"Oguz C.",
""
]
] |
0706.1038 | Masahiro Takeoka | Masahiro Takeoka and Masahide Sasaki | Discrimination of the binary coherent signal: Gaussian-operation limit
and simple non-Gaussian near-optimal receivers | 7 pages, 4 figures, published version | Phys. Rev. A 78, 022320 (2008) | 10.1103/PhysRevA.78.022320 | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We address the limit of the Gaussian operations and classical communication
in the problem of quantum state discrimination. We show that the optimal
Gaussian strategy for the discrimination of the binary phase shift keyed (BPSK)
coherent signal is a simple homodyne detection. We also propose practical
near-optimal quantum receivers that beat the BPSK homodyne limit in all areas
of the signal power. Our scheme is simple and does not require realtime
electrical feedback.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 16:48:15 GMT"
},
{
"version": "v2",
"created": "Wed, 2 Jul 2008 06:35:33 GMT"
},
{
"version": "v3",
"created": "Thu, 14 Aug 2008 05:53:35 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Takeoka",
"Masahiro",
""
],
[
"Sasaki",
"Masahide",
""
]
] |
0706.1039 | Jorge Portoles | V. Mateu and J. Portoles (IFIC, Valencia) | Form Factors in the radiative pion decay | 14 pages, no figures. Typos corrected. Accepted for publication in
The European Physical Journal C | Eur.Phys.J.C52:325-338,2007 | 10.1140/epjc/s10052-007-0393-5 | IFIC/07-29, FTUV-07-0607 | hep-ph hep-ex hep-lat | null | We perform an analysis of the form factors that rule the structure-dependent
amplitude in the radiative pion decay. The resonance contributions to pion -> e
nu_e gamma decays are computed through the proper construction of the vector
and axial-vector form factors by setting the QCD driven asymptotic properties
of the three-point Green functions VVP and VAP, and by demanding the smoothing
of the form factors at high transfer of momentum. A comparison between
theoretical and experimental determinations of the form factors is also carried
out. We also consider and evaluate the role played by a non-standard tensor
form factor. We conclude that, at present and due to the hadronic incertitudes,
the search for New Physics in this process is not feasible.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 16:51:41 GMT"
},
{
"version": "v2",
"created": "Tue, 7 Aug 2007 10:15:47 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Mateu",
"V.",
"",
"IFIC, Valencia"
],
[
"Portoles",
"J.",
"",
"IFIC, Valencia"
]
] |
0706.1040 | Moshe Elitzur | Andr\'es Asensio Ramos, Cecilia Ceccarelli and Moshe Elitzur | H$_2$D$^+$ line emission in Proto-Planetary Disks | To appear in A&A | null | 10.1051/0004-6361:20077458 | null | astro-ph | null | %Context: {Previous studies have indicated that the 372.4 GHz ground
transition of ortho-H$_2$D$^+$ might be a powerful probe of Proto-Planetary
Disks. The line could be especially suited for study of the disk mid-plane,
where the bulk of the mass resides and where planet formation takes place.}
%Aims: {Provide detailed theoretical predictions for the line intensity,
profile and maps expected for representative disk models.} %Methods: {We
determine the physical and chemical structure of the disks from the model
developed by Ceccarelli & Dominik (2005). The line emission is computed with
the new radiative transfer method developed recently by Elitzur & Asensio Ramos
(2006).} %Results: {We present intensity maps convolved with the expected ALMA
resolution, which delineate the origin of the H$_2$D$^+$ 372.4 GHz line. In the
disk inner regions, the line probes the conditions in the mid-plane out to
radial distances of a few tens of AU, where Solar-like planetary systems might
form. In the disk outermost regions, the line originates from slightly above
the mid-plane. When the disk is spatially resolved, the variation of line
profile across the image provides important information about the velocity
field. Spectral profiles of the entire disk flux show a double peak shape at
most inclination angles.} %Conclusions: {Our study confirms that the 372.4 GHz
H$_2$D$^+$ line provides powerful diagnostics of the mid-plane of
Proto-Planetary Disks. Current submillimeter telescopes are capable of
observing this line, though with some difficulties. The future ALMA
interferometer will have the sensitivity to observe and even spatially resolve
the H$_2$D$^+$ line emission.}
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:01:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ramos",
"Andrés Asensio",
""
],
[
"Ceccarelli",
"Cecilia",
""
],
[
"Elitzur",
"Moshe",
""
]
] |
0706.1041 | Hanns-Christoph Naegerl | M. Mark, F. Ferlaino, S. Knoop, J.G. Danzl, T. Kraemer, C. Chin, H.-C.
Naegerl, R. Grimm | Spectroscopy of Ultracold, Trapped Cesium Feshbach Molecules | 15 pages, 12 figures, 4 tables | Phys. Rev. A 76, 042514 (2007) | 10.1103/PhysRevA.76.042514 | null | cond-mat.other | null | We explore the rich internal structure of Cs_2 Feshbach molecules. Pure
ultracold molecular samples are prepared in a CO_2-laser trap, and a multitude
of weakly bound states is populated by elaborate magnetic-field ramping
techniques. Our methods use different Feshbach resonances as input ports and
various internal level crossings for controlled state transfer. We populate
higher partial-wave states of up to eight units of rotational angular momentum
(l-wave states). We investigate the molecular structure by measurements of the
magnetic moments for various states. Avoided level crossings between different
molecular states are characterized through the changes in magnetic moment and
by a Landau-Zener tunneling method. Based on microwave spectroscopy, we present
a precise measurement of the magnetic-field dependent binding energy of the
weakly bound s-wave state that is responsible for the large background
scattering length of Cs. This state is of particular interest because of its
quantum-halo character.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:08:30 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Mark",
"M.",
""
],
[
"Ferlaino",
"F.",
""
],
[
"Knoop",
"S.",
""
],
[
"Danzl",
"J. G.",
""
],
[
"Kraemer",
"T.",
""
],
[
"Chin",
"C.",
""
],
[
"Naegerl",
"H. -C.",
""
],
[
"Grimm",
"R.",
""
]
] |
0706.1042 | Stuart D. Wick | Triston Dougall, Stuart D. Wick | Dirac Magnetic Monopole Production from Photon Fusion in Proton
Collisions | 9 pages, 4 figures, minor correction, one reference added | Eur.Phys.J.A39:213-217,2009 | 10.1140/epja/i2008-10701-8 | null | hep-ph hep-ex | null | We calculate the lowest order cross--section for Dirac magnetic monopole
production from photon fusion in p p-bar collisions at sqrt{s}=1.96 TeV, p p
collisions at sqrt{s}=14 TeV, and we compare photon fusion with Drell--Yan (DY)
production. We find the total photon fusion cross--section is comparable with
DY at sqrt{s}=1.96 TeV and dominates DY by a factor ~50 at sqrt{s}=14 TeV. We
conclude that both the photon fusion and DY processes allow for a monopole mass
limit m>370 GeV based upon the null results of the recent monopole search at
the Collider Detector at Fermilab (CDF). We also conclude that photon fusion is
the leading production mechanism to be considered for direct monopole searches
at the Large Hadron Collider (LHC).
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:17:23 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Feb 2008 17:57:40 GMT"
}
] | 2011-07-19T00:00:00 | [
[
"Dougall",
"Triston",
""
],
[
"Wick",
"Stuart D.",
""
]
] |
0706.1043 | Erich Popptiz | Erich Poppitz, Yanwen Shang | Lattice chirality and the decoupling of mirror fermions | 29 pages, 2 figures; published version, new addendum | JHEP0708:081,2007 | 10.1088/1126-6708/2007/08/081 | null | hep-th hep-lat | null | We show, using exact lattice chirality, that partition functions of lattice
gauge theories with vectorlike fermion representations can be split into
"light" and "mirror" parts, such that the "light" and "mirror" representations
are chiral. The splitting of the full partition function into "light" and
"mirror" is well defined only if the two sectors are separately anomaly free.
We show that only then is the generating functional, and hence the spectrum, of
the mirror theory a smooth function of the gauge field background. This
explains how ideas to use additional non-gauge, high-scale mirror-sector
dynamics to decouple the mirror fermions without breaking the gauge
symmetry--for example, in symmetric phases at strong mirror Yukawa
coupling--are forced to respect the anomaly-free condition when combined with
the exact lattice chiral symmetry. Our results also explain a paradox posed by
a recent numerical study of the mirror-fermion spectrum in a toy
would-be-anomalous two-dimensional theory. In passing, we prove some general
properties of the partition functions of arbitrary chiral theories on the
lattice that should be of interest for further studies in this field.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:18:34 GMT"
},
{
"version": "v2",
"created": "Tue, 4 Sep 2007 18:02:31 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Poppitz",
"Erich",
""
],
[
"Shang",
"Yanwen",
""
]
] |
0706.1044 | Ludovic Berthier | Ludovic Berthier, Robert L. Jack | Structure and dynamics in glass-formers: predictability at large length
scales | 7 pages; 4 figs - Extended, clarified version | Phys. Rev. E 76, 041509 (2007) | 10.1103/PhysRevE.76.041509 | null | cond-mat.stat-mech | null | Dynamic heterogeneity in glass-formers has been related to their static
structure using the concept of dynamic propensity. We re-examine this
relationship by analyzing dynamical fluctuations in two atomistic glass-formers
and two theoretical models. We introduce quantitative statistical indicators
which show that the dynamics of individual particles cannot be predicted on the
basis of the propensity, nor by any structural indicator. However, the spatial
structure of the propensity field does have predictive power for the spatial
correlations associated with dynamic heterogeneity. Our results suggest that
the quest for a connection between static and dynamic properties of
glass-formers at the particle level is vain, but they demonstrate that such
connection does exist on larger length scales.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:25:54 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Aug 2007 13:30:51 GMT"
}
] | 2009-08-25T00:00:00 | [
[
"Berthier",
"Ludovic",
""
],
[
"Jack",
"Robert L.",
""
]
] |
0706.1045 | Mikhail Kotchetov | Yuri Bahturin, Mikhail Kochetov, Susan Montgomery | Group gradings on simple Lie algebras of type A in positive
characteristic | null | null | null | null | math.RA | null | In this paper we consider gradings by a finite abelian group $G$ on the Lie
algebra $\mathfrak{sl}_n(F)$ over an algebraically closed field $F$ of
characteristic different from 2 and not dividing $n$.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:27:17 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Bahturin",
"Yuri",
""
],
[
"Kochetov",
"Mikhail",
""
],
[
"Montgomery",
"Susan",
""
]
] |
0706.1046 | Matteo Petrera | Rafael Hernandez Heredero, Decio Levi, Matteo Petrera, Christian
Scimiterna | Multiscale expansion of the lattice potential KdV equation on functions
of infinite slow-varyness order | 9 pages, submitted to Journ. Phys. A | null | 10.1088/1751-8113/40/4/017 | null | math-ph math.MP | null | We present a discrete multiscale expansion of the lattice potential
Korteweg-de Vries (lpKdV) equation on functions of infinite order of
slow-varyness. To do so we introduce a formal expansion of the shift operator
on many lattices holding at all orders. The lowest secularity condition from
the expansion of the lpKdV equation gives a nonlinear lattice equation,
depending on shifts of all orders, of the form of the nonlinear Schr\"odinger
(NLS) equation
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:37:39 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Heredero",
"Rafael Hernandez",
""
],
[
"Levi",
"Decio",
""
],
[
"Petrera",
"Matteo",
""
],
[
"Scimiterna",
"Christian",
""
]
] |
0706.1047 | David Charbonneau | David Charbonneau and Drake Deming | The Dynamics-Based Approach to Studying Terrestrial Exoplanets | submitted to the Exoplanet Task Force (AAAC), 2 April 2007 | null | null | null | astro-ph | null | One of the great quests of astronomy is to obtain the spectrum of a
terrestrial planet orbiting within the habitable zone of its star, and the
dominant challenge in doing so is to isolate the light of the planet from that
of the star. Dynamics-based methods separate these signals temporally, whereas
imaging techniques do so spatially. In light of the overwhelming dominance of
dynamics-based methods over the past decade, we challenge the notion that
spectra of terrestrial planets necessarily require extreme imaging methods. We
advocate that some resources be committed to refining the proven technologies
of radial-velocity measurements, transit photometry, and occultation
spectroscopy (i.e. emergent infrared spectra obtained at secondary eclipse). We
see a particularly attractive opportunity in M-dwarfs, for which the habitable
zone is close to the star, increasing the probability and frequency of
transits, and the amplitude of the induced radial-velocity variation. Such
planets could be discovered by a dedicated ground-based transit survey of the
10,000 nearest M-dwarfs. The favorable planet-star contrast ratio would make
these planets ideal targets for the study of their atmospheres with the
technique of occultation spectroscopy.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:39:11 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Charbonneau",
"David",
""
],
[
"Deming",
"Drake",
""
]
] |
0706.1048 | Nicolas Saintier | Nicolas Saintier | Estimates of the best Sobolev constant of the embedding of $BV(\Omega)$
into $L^1(\partial\Omega)$ and related shape optimization problems | null | null | null | null | math.AP | null | In this paper we find estimates for the optimal constant in the critical
Sobolev trace inequality $\lambda_1(\Omega)\|u\|_{L^1(\partial\Omega)} \le
\|u\|_{W^{1,1}(\Omega)}$ that are independent of $\Omega$. This estimates
generalize those of \cite{BS} concerning the $p$-Laplacian to the case $p=1$.
We apply our results to prove existence of an extremal for this embedding. We
then study an optimal design problem related to $\lambda_1$, and eventually
compute the shape derivative of the functional $\Omega\to\lambda_1(\Omega)$. As
a consequence, we obtain that a ball of $\R^n$ of radius $n$ is critical for
volume-preserving deformations.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:52:31 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Saintier",
"Nicolas",
""
]
] |
0706.1049 | Vikram Dwarkadas | Vikram V. Dwarkadas | The Evolution of Supernovae in Circumstellar Wind Bubbles II: Case of a
Wolf-Rayet star | 50 pages, 19 figures. Accepted to the Astrophysical Journal. For a
version with the original high-resolution color figures please download from
http://astro.uchicago.edu/~vikram/sncsm.html | Astrophys.J.667:226-247,2007 | 10.1086/520670 | null | astro-ph | null | (Abridged) Mass-loss from massive stars leads to the formation of
circumstellar wind-blown bubbles surrounding the star, bordered by a dense
shell. When the star ends its life in a supernova (SN) explosion, the resulting
shock wave will interact with this modified medium. In a previous paper we
discussed the basic parameters of this interaction. In this paper we go a step
further and study the evolution of SNe in the wind blown bubble formed by a 35
$\msun$ star that starts off as an O star, goes through a red supergiant phase,
and ends its life as a Wolf-Rayet star. We model the evolution of the CSM and
then the expansion of the SN shock wave within this medium. Our simulations
clearly reveal fluctuations in density and pressure within the surrounding
medium. The SN shock interacting with these fluctuations, and then with the
dense shell surrounding the wind-blown cavity, gives rise to a variety of
transmitted and reflected shocks in the wind bubble. The interactions between
these various shocks and discontinuities is examined, and its effects on the
X-ray emission is noted. Our simulations reveal the presence of several
hydrodynamic instabilities. They show that the turbulent interior, coupled with
the large fluctuations in density and pressure, gives rise to an extremely
corrugated SN shock wave. The shock shows considerable wrinkles as it impacts
the dense shell, and the impact occurs in a piecemeal fashion, with some parts
of the shock wave interacting with the shell before the others. Therefore
different parts of the shell will `light-up' at different times. The
non-spherical nature of the interaction means that it will occur over a
prolonged period of time, and the spherical symmetry of the initial shock wave
is destroyed.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 17:54:21 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Dwarkadas",
"Vikram V.",
""
]
] |
0706.1050 | Rachel Dudik Ms. | S. Satyapal, D. Vega, T. Heckman, B. O'Halloran and R. Dudik | The Discovery of an Active Galactic Nucleus in the Late-type Galaxy NGC
3621: Spitzer Spectroscopic Observations | 5 pages, 7 figures, Accepted for publication in ApJ Letters | null | 10.1086/519995 | null | astro-ph | null | We report the discovery of an Active Galactic Nucleus (AGN) in the nearby SAd
galaxy NGC 3621 using Spitzer high spectral resolution observations. These
observations reveal the presence of [NeV] 14 um and 24 um emission which is
centrally concentrated and peaks at the position of the near-infrared nucleus.
Using the [NeV] line luminosity, we estimate that the nuclear bolometric
luminosity of the AGN is ~ 5 X 10^41 ergs s^-1, which corresponds based on the
Eddington limit to a lower mass limit of the black hole of ~ 4 X 10^3 Msun.
Using an order of magnitude estimate for the bulge mass based on the Hubble
type of the galaxy, we find that this lower mass limit does not put a strain on
the well-known relationship between the black hole mass and the host galaxy's
stellar velocity dispersion established in predominantly early-type galaxies.
Mutli-wavelength follow-up observations of NGC 3621 are required to obtain more
precise estimates of the bulge mass, black hole mass, accretion rate, and
nuclear bolometric luminosity. The discovery reported here adds to the growing
evidence that a black hole can form and grow in a galaxy with no or minimal
bulge.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 18:07:49 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Satyapal",
"S.",
""
],
[
"Vega",
"D.",
""
],
[
"Heckman",
"T.",
""
],
[
"O'Halloran",
"B.",
""
],
[
"Dudik",
"R.",
""
]
] |
0706.1051 | Donald Sofge | Donald A. Sofge and David L. Elliott | Improved Neural Modeling of Real-World Systems Using Genetic Algorithm
Based Variable Selection | 4 pages | D. Sofge and D. Elliott, "Improved Neural Modeling of Real-World
Systems Using Genetic Algorithm Based Variable Selection," In Int'l Conf. on
Neural Networks and Brain (ICNN&B'98-Beijing), 1998 | null | null | cs.NE | null | Neural network models of real-world systems, such as industrial processes,
made from sensor data must often rely on incomplete data. System states may not
all be known, sensor data may be biased or noisy, and it is not often known
which sensor data may be useful for predictive modelling. Genetic algorithms
may be used to help to address this problem by determining the near optimal
subset of sensor variables most appropriate to produce good models. This paper
describes the use of genetic search to optimize variable selection to determine
inputs into the neural network model. We discuss genetic algorithm
implementation issues including data representation types and genetic operators
such as crossover and mutation. We present the use of this technique for neural
network modelling of a typical industrial application, a liquid fed ceramic
melter, and detail the results of the genetic search to optimize the neural
network model for this application.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 18:13:59 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Sofge",
"Donald A.",
""
],
[
"Elliott",
"David L.",
""
]
] |
0706.1052 | Dan Stamper-Kurn | Subhadeep Gupta, Kevin L. Moore, Kater W. Murch and Dan M.
Stamper-Kurn | Cavity Nonlinear Optics at Low Photon Numbers from Collective Atomic
Motion | 4 pages, 3 figures. Modifed following reviewer comments | null | 10.1103/PhysRevLett.99.213601 | null | quant-ph | null | We report on Kerr nonlinearity and dispersive optical bistability of a
Fabry-Perot optical resonator due to the displacement of ultracold atoms
trapped within. In the driven resonator, such collective motion is induced by
optical forces acting upon up to $10^5$ $^{87}$Rb atoms prepared in the lowest
band of a one-dimensional intracavity optical lattice. The longevity of atomic
motional coherence allows for strongly nonlinear optics at extremely low cavity
photon numbers, as demonstrated by the observation of both branches of optical
bistability at photon numbers below unity.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:09:19 GMT"
},
{
"version": "v2",
"created": "Wed, 5 Sep 2007 02:27:35 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gupta",
"Subhadeep",
""
],
[
"Moore",
"Kevin L.",
""
],
[
"Murch",
"Kater W.",
""
],
[
"Stamper-Kurn",
"Dan M.",
""
]
] |
0706.1053 | Simona Gallerani | S. Gallerani, A. Ferrara, X. Fan, T. R. Choudhury | Glimpsing through the high redshift neutral hydrogen fog | 12 pages, 9 figures, revised to match the accepted version including
a detailed analysis of the foreground QSO redshift and of the relativistic
effects on the HII region shape; MNRAS in press | null | 10.1111/j.1365-2966.2008.13029.x | null | astro-ph | null | We analyze the transmitted flux in a sample of 17 QSOs spectra at
5.74<zem<6.42 to obtain tighter constraints on the volume-averaged neutral
hydrogen fraction, xHI, at z~6. We study separately the narrow transmission
windows (peaks) and the wide dark portions (gaps) in the observed absorption
spectra. By comparing the statistics of these spectral features with Lyalpha
forest simulations, we conclude that xHI evolves smoothly from 10^{-4.4} at
z=5.3 to 10^{-4.2} at z=5.6, with a robust upper limit xHI<0.36 at z=6.3. The
frequency and physical sizes of the peaks imply an origin in cosmic underdense
regions and/or in HII regions around faint quasars or galaxies. In one case
(the intervening HII region of the faint quasar RD J1148+5253 at z=5.70 along
the LOS of SDSS J1148+5251 at z=6.42) the increase of the peak spectral density
is explained by the first-ever detected transverse proximity effect in the HI
Lyalpha forest; this indicates that at least some peaks result from a locally
enhanced radiation field. We then obtain a strong lower limit on the foreground
QSO lifetime of tQ>11 Myr. The observed widths of the peaks are found to be
systematically larger than the simulated ones. Reasons for such discrepancy
might reside either in the photoionization equilibrium assumption or in
radiative transfer effects.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:15:49 GMT"
},
{
"version": "v2",
"created": "Wed, 30 Jan 2008 13:02:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gallerani",
"S.",
""
],
[
"Ferrara",
"A.",
""
],
[
"Fan",
"X.",
""
],
[
"Choudhury",
"T. R.",
""
]
] |
0706.1054 | Joseph Gelfand | Joseph D. Gelfand, B. M. Gaensler | The Compact X-ray Source 1E 1547.0-5408 and the Radio Shell
G327.24-0.13: A New Proposed Association between a Candidate Magnetar and a
Candidate Supernova Remnant | 11 pages, 5 figures, ApJ accepted | null | 10.1086/520526 | null | astro-ph | null | We present X-ray, infrared and radio observations of the field centered on
X-ray source 1E 1547.0-5408 in the Galactic Plane. A new Chandra observation of
this source shows it is unresolved at arc-second resolution, and a new XMM
observation shows that its X-ray spectrum is best described by an absorbed
power-law and blackbody model. A comparison of the X-ray flux observed from
this source between 1980 and 2006 reveals that its absorbed 0.5-10 keV X-ray
flux decreased from ~2x10^-12 ergs cm-2 s-1 to ~3x10^-13 ergs cm-2 during this
period. The most recent XMM observation allows us to put a 5 sigma confidence
upper limit of 14% for the 0.5-10 keV peak-to-peak pulsed fraction. A
near-infrared observation of this field shows a source with magnitude Ks =
15.9+/-0.2 near the position of 1E 1547.0-5408, but the implied X-ray to
infrared flux ratio indicates the infrared emission is from an unrelated field
source, allowing us to limit the IR magnitude of 1E 1547.0-5408 to >17.5.
Archival radio observations reveal that 1E 1547.0-5408 sits at the center of a
faint, small (4' diameter) radio shell, G327.24-0.13, which is possibly a
previously unidentified supernova remnant. The X-ray properties of 1E
1547.0-5408 suggest that this source is a magnetar - a young neutron star whose
X-ray emission is powered by the decay of its extremely strong magnetic field.
The spatial coincidence between this source and G327.24-0.13 suggests that 1E
1547.0-5408 is associated with a young supernova remnant, supporting a neutron
star interpretation. Additional observations are needed to confirm the nature
of both 1E 1547.0-5408 and G327.24-0.13, and to determine if these sources are
associated. If so, this pair will be an important addition to the small number
of known associations between magnetars and supernova remnants.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 18:35:12 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gelfand",
"Joseph D.",
""
],
[
"Gaensler",
"B. M.",
""
]
] |
0706.1055 | Ibrahim Abou Hamad | Ibrahim Abou Hamad, Daniel T. Robb, Mark A. Novotny, Per Arne Rikvold | EC-FORC: A New Cyclic Voltammetry Based Method for Examining Phase
Transitions and Predicting Equilibrium | 8 pages, 4 figures, 211th ECS Meeting | ECS Trans. 6 (19), 53-60 (2008). | 10.1149/1.2831729 | null | physics.chem-ph cond-mat.mtrl-sci cond-mat.stat-mech | null | We propose a new, cyclic-voltammetry based experimental technique that can
not only differentiate between discontinuous and continuous phase transitions
in an adsorbate layer, but also quite accurately recover equilibrium behavior
from dynamic analysis of systems with a continuous phase transition. The
Electrochemical first-order reversal curve (EC-FORC) diagram for a
discontinuous phase transition (nucleation and growth), such as occurs in
underpotential deposition, is characterized by a negative region, while such a
region does not exist for a continuous phase transition, such as occurs in the
electrosorption of Br on Ag(100). Moreover, for systems with a continuous phase
transition, the minima of the individual EC-FORCs trace the equilibrium curve,
even at very high scan rates. Since obtaining experimental data for the EC-FORC
method would require only a simple reprogramming of the potentiostat used in
conventional cyclic-voltammetry experiments, we believe that this method has
significant potential for easy, rapid, in-situ analysis of systems undergoing
electrochemical deposition.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 18:40:52 GMT"
},
{
"version": "v2",
"created": "Mon, 11 Jun 2007 18:10:36 GMT"
}
] | 2008-02-26T00:00:00 | [
[
"Hamad",
"Ibrahim Abou",
""
],
[
"Robb",
"Daniel T.",
""
],
[
"Novotny",
"Mark A.",
""
],
[
"Rikvold",
"Per Arne",
""
]
] |
0706.1056 | Per Kristian Rekdal | Bo-Sture K. Skagerstam and Per Kristian Rekdal | Spontaneous Emission Near Superconducting Bodies | 7 pages, 5 figures | null | 10.1103/PhysRevA.76.052901 | null | quant-ph | null | In the present paper we study the spontaneous photon emission due to a
magnetic spin-flip transition of a two-level atom in the vicinity of a
dielectric body like a normal conducting metal or a superconductor. For
temperatures below the transition temperature T_c of a superconductor, the
corresponding spin-flip lifetime is boosted by several orders of magnitude as
compared to the case of a normal conducting body. Numerical results of an exact
formulation are also compared to a previously derived approximative analytical
expression for the spin-flip lifetime and we find an excellent agreement. We
present results on how the spin-flip lifetime depends on the temperature T of a
superconducting body as well as its thickness H. Finally, we study how
non-magnetic impurities as well as possible Eliashberg strong-coupling effects
influence the spin-flip rate. It is found that non-magnetic impurities as well
as strong-coupling effects have no dramatic impact on the spin-flip lifetime.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 18:50:40 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Skagerstam",
"Bo-Sture K.",
""
],
[
"Rekdal",
"Per Kristian",
""
]
] |
0706.1057 | Martin Bojowald | Martin Bojowald, Hector Hernandez, Aureliano Skirzewski | Effective equations for isotropic quantum cosmology including matter | 42 pages | Phys.Rev.D76:063511,2007 | 10.1103/PhysRevD.76.063511 | IGPG-07/6-2 | gr-qc astro-ph hep-th | null | Effective equations often provide powerful tools to develop a systematic
understanding of detailed properties of a quantum system. This is especially
helpful in quantum cosmology where several conceptual and technical
difficulties associated with the full quantum equations can be avoided in this
way. Here, effective equations for Wheeler-DeWitt and loop quantizations of
spatially flat, isotropic cosmological models sourced by a massive or
interacting scalar are derived and studied. The resulting systems are
remarkably different from that given for a free, massless scalar. This has
implications for the coherence of evolving states and the realization of a
bounce in loop quantum cosmology.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 18:58:32 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bojowald",
"Martin",
""
],
[
"Hernandez",
"Hector",
""
],
[
"Skirzewski",
"Aureliano",
""
]
] |
0706.1058 | Michael R. Peterson | Michael R. Peterson, Subroto Mukerjee, B. Sriram Shastry, and Jan O.
Haerter | Dynamical thermal response functions for strongly correlated
one-dimensional systems | 15 pages, 12 figures | Phys. Rev. B 76, 125110 (2007) (14 pages) | 10.1103/PhysRevB.76.125110 | null | cond-mat.str-el | null | In this article we study the thermal response functions for two
one-dimensional models, namely the Hubbard and spin-less fermion $t$-$V$
models. By exactly diagonalizing finite sized systems we calculate dynamical
electrical, thermoelectrical, and thermal conductivities via the Kubo
formalism. The thermopower (Seebeck coefficient), Lorenz number, and
dimensionless figure of merit are then constructed which are quantities of
great interest to the physics community both theoretically and experimentally.
We also geometrically frustrate these systems and destroy integrability by the
inclusion of a second neighbor hop. These frustrated systems are shown to have
enhanced thermopower and Lorenz number at intermediate and low temperatures.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:07:37 GMT"
}
] | 2013-05-29T00:00:00 | [
[
"Peterson",
"Michael R.",
""
],
[
"Mukerjee",
"Subroto",
""
],
[
"Shastry",
"B. Sriram",
""
],
[
"Haerter",
"Jan O.",
""
]
] |
0706.1059 | James Burke | The BaBar Collaboration, B. Aubert, et al | Search for the decay B+ -> Kbar*0(892) K+ | 8 pages, 6 .eps figures, intended for PRD-RC. Revision (Nov 27, 2007)
- minor typographic changes as requested by PRD referee; analysis and results
unchanged | Phys.Rev.D76:071103,2007 | 10.1103/PhysRevD.76.071103 | BABAR-PUB-07/004, SLAC-PUB-12546 | hep-ex | null | We report on a search for the process B+ -> Kbar*0(892) K+ using 232 10^6
Upsilon(4S) -> BBbar decays collected with the BaBar detector at the PEP-II
asymmetric-energy B Factory at SLAC. From a signal yield of 25 +/- 13 [stat]
+/- 7 [syst] B+ -> Kbar*0(892) (-> K- pi+) K+ events, we place an upper limit
on the branching fraction BF(B+ -> Kbar*0(892) K+) of 1.1 10^-6, at the 90%
confidence level.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:37:44 GMT"
},
{
"version": "v2",
"created": "Tue, 27 Nov 2007 23:35:42 GMT"
}
] | 2010-04-12T00:00:00 | [
[
"The BaBar Collaboration",
"",
""
],
[
"Aubert",
"B.",
""
]
] |
0706.1060 | Jake Koralek | J. D. Koralek, J. F. Douglas, N. C. Plumb, J. D. Griffith, S. T.
Cundiff, H. C. Kapteyn, M. M. Murnane, D. S. Dessau | Experimental setup for low-energy laser-based angle resolved
photoemission spectroscopy | Please download final version from Journal-Ref | REVIEW OF SCIENTIFIC INSTRUMENTS 78, 053905 (2007) | 10.1063/1.2722413 | null | cond-mat.other cond-mat.mtrl-sci cond-mat.supr-con | null | A laser-based angle resolved photoemission (APRES) system utilizing 6 eV
photons from the fourth harmonic of a mode-locked Ti:sapphire oscillator is
described. This light source greatly increases the momentum resolution and
photoelectron count rate, while reducing extrinsic background and surface
sensitivity relative to higher energy light sources. In this review, the
optical system is described, and special experimental considerations for
low-energy ARPES are discussed. The calibration of the hemispherical electron
analyzer for good low-energy angle-mode performance is also described. Finally,
data from the heavily studied high T_c superconductor Bi2Sr2CaCu2O8+\delta
(Bi2212) is compared to the results from higher photon energies.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:27:08 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Koralek",
"J. D.",
""
],
[
"Douglas",
"J. F.",
""
],
[
"Plumb",
"N. C.",
""
],
[
"Griffith",
"J. D.",
""
],
[
"Cundiff",
"S. T.",
""
],
[
"Kapteyn",
"H. C.",
""
],
[
"Murnane",
"M. M.",
""
],
[
"Dessau",
"D. S.",
""
]
] |
0706.1061 | Donald Sofge | Donald Sofge and Gerald Chiang | Design, Implementation, and Cooperative Coevolution of an Autonomous/
Teleoperated Control System for a Serpentine Robotic Manipulator | null | D. Sofge and G. Chiang, "Design, ... a Serpentine Automated Waste
Retrieval Manipulator," Amer. Nucl. Soc. 9th Top. Meeting on Robotics and
Remote Systems, 2001 | null | null | cs.NE cs.RO | null | Design, implementation, and machine learning issues associated with
developing a control system for a serpentine robotic manipulator are explored.
The controller developed provides autonomous control of the serpentine robotic
manipulatorduring operation of the manipulator within an enclosed environment
such as an underground storage tank. The controller algorithms make use of both
low-level joint angle control employing force/position feedback constraints,
and high-level coordinated control of end-effector positioning. This approach
has resulted in both high-level full robotic control and low-level telerobotic
control modes, and provides a high level of dexterity for the operator.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:27:12 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Sofge",
"Donald",
""
],
[
"Chiang",
"Gerald",
""
]
] |
0706.1062 | Aaron Clauset | Aaron Clauset, Cosma Rohilla Shalizi, M. E. J. Newman | Power-law distributions in empirical data | 43 pages, 11 figures, 7 tables, 4 appendices; code available at
http://www.santafe.edu/~aaronc/powerlaws/ | SIAM Review 51, 661-703 (2009) | 10.1137/070710111 | null | physics.data-an cond-mat.dis-nn stat.AP stat.ME | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Power-law distributions occur in many situations of scientific interest and
have significant consequences for our understanding of natural and man-made
phenomena. Unfortunately, the detection and characterization of power laws is
complicated by the large fluctuations that occur in the tail of the
distribution -- the part of the distribution representing large but rare events
-- and by the difficulty of identifying the range over which power-law behavior
holds. Commonly used methods for analyzing power-law data, such as
least-squares fitting, can produce substantially inaccurate estimates of
parameters for power-law distributions, and even in cases where such methods
return accurate answers they are still unsatisfactory because they give no
indication of whether the data obey a power law at all. Here we present a
principled statistical framework for discerning and quantifying power-law
behavior in empirical data. Our approach combines maximum-likelihood fitting
methods with goodness-of-fit tests based on the Kolmogorov-Smirnov statistic
and likelihood ratios. We evaluate the effectiveness of the approach with tests
on synthetic data and give critical comparisons to previous approaches. We also
apply the proposed methods to twenty-four real-world data sets from a range of
different disciplines, each of which has been conjectured to follow a power-law
distribution. In some cases we find these conjectures to be consistent with the
data while in others the power law is ruled out.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:33:07 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Feb 2009 17:49:43 GMT"
}
] | 2009-11-12T00:00:00 | [
[
"Clauset",
"Aaron",
""
],
[
"Shalizi",
"Cosma Rohilla",
""
],
[
"Newman",
"M. E. J.",
""
]
] |
0706.1063 | Matthias Brust R. | Matthias R. Brust, Steffen Rothkugel | Small Worlds: Strong Clustering in Wireless Networks | To appear in: 1st International Workshop on Localized Algorithms and
Protocols for Wireless Sensor Networks (LOCALGOS 2007), 2007, IEEE Compuster
Society Press | null | null | null | cs.NI cs.DC cs.DS | null | Small-worlds represent efficient communication networks that obey two
distinguishing characteristics: a high clustering coefficient together with a
small characteristic path length. This paper focuses on an interesting paradox,
that removing links in a network can increase the overall clustering
coefficient. Reckful Roaming, as introduced in this paper, is a 2-localized
algorithm that takes advantage of this paradox in order to selectively remove
superfluous links, this way optimizing the clustering coefficient while still
retaining a sufficiently small characteristic path length.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:42:51 GMT"
},
{
"version": "v2",
"created": "Mon, 11 Jun 2007 05:36:04 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Brust",
"Matthias R.",
""
],
[
"Rothkugel",
"Steffen",
""
]
] |
0706.1064 | Kenichi Nakano | Kenichi Nakano (PHENIX Collaboration) | Measurement of Double Helicity Asymmetry in Multi-Particle Production
with Polarized Proton-Proton Collision at PHENIX | 4 pages, 2 figures, to be published in the Proceedings of the 17th
International Spin Physics Symposium | AIPConf.Proc.915:371-374,2007 | 10.1063/1.2750799 | null | nucl-ex | null | A goal of the PHENIX experiment is to obtain the polarized gluon distribution
function in the proton. Double helicity asymmetry in multi-particle production
with polarized proton-proton collision is measured at midrapidity with RHIC Run
2005 data. This result excludes the maximum positive gluon polarization
("GRSV-max").
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:55:24 GMT"
},
{
"version": "v2",
"created": "Mon, 11 Jun 2007 19:24:32 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Nakano",
"Kenichi",
"",
"PHENIX Collaboration"
]
] |
0706.1065 | Paul M. Terwilliger | Tatsuro Ito and Paul Terwilliger | Tridiagonal pairs of Krawtchouk type | 20 pages | null | null | null | math.RA math.RT | null | Let $K$ denote an algebraically closed field with characteristic 0 and let
$V$ denote a vector space over $K$ with finite positive dimension. Let $A,A^*$
denote a tridiagonal pair on $V$ with diameter $d$. We say that $A,A^*$ has
Krawtchouk type whenever the sequence $\lbrace d-2i\rbrace_{i=0}^d$ is a
standard ordering of the eigenvalues of $A$ and a standard ordering of the
eigenvalues of $A^*$. Assume $A,A^*$ has Krawtchouk type. We show that there
exists a nondegenerate symmetric bilinear form $< , >$ on $V$ such that
$<Au,v>= < u,Av>$ and $<A^*u,v >= < u,A^*v>$ for $u,v\in V$. We show that the
following tridiagonal pairs are isomorphic: (i) $A,A^*$; (ii) $-A,-A^*$; (iii)
$A^*,A$; (iv) $-A^*,-A$. We give a number of related results and conjectures.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:41:52 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Ito",
"Tatsuro",
""
],
[
"Terwilliger",
"Paul",
""
]
] |
0706.1066 | Matthias Brust R. | Matthias R. Brust | Applying Test-Paradigms in a Generic Tutoring System Concept for
Web-based Learning | Information and Resource Management (IRMA 2003) | null | null | null | cs.CY | null | Realizing test scenarios through a tutoring system involve questions about
architecture and didactic methods in such a system. Observing the fact that
traditional tutoring systems normally are domain-static, this paper shows
investigations for a generic domain-independent tutoring system for utilizing
test scenarios in computer-based and web-based environments. Furthermore, test
paradigms are analyzed and it is presented an approach for realizing
functionality for applying test paradigms in the presented generic tutoring
system architecture by an XML-specified language.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:55:11 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Brust",
"Matthias R.",
""
]
] |
0706.1067 | Andrea Costa | Andrea Costa and Rafael Gonzalez | Stability and mode analysis of solar coronal loops using thermodynamic
irreversible energy principles | 29 pages 10 figures | Astron.Astrophys.458:953,2006 | 10.1051/0004-6361:20065206 | null | astro-ph | null | We study the modes and stability of non - isothermal coronal loop models with
different intensity values of the equilibrium magnetic field. We use an energy
principle obtained via non - equilibrium thermodynamic arguments. The principle
is expressed in terms of Hermitian operators and allow to consider together the
coupled system of equations: the balance of energy equation and the equation of
motion. We determine modes characterized as long - wavelength disturbances that
are present in inhomogeneous media. This character of the system introduces
additional difficulties for the stability analysis because the inhomogeneous
nature of the medium determines the structure of the disturbance, which is no
longer sinusoidal. Moreover, another complication is that we obtain a
continuous spectrum of stable modes in addition to the discrete one. We obtain
a unique unstable mode with a characteristic time that is comparable with the
characteristic life-time observed for loops. The feasibility of wave-based and
flow-based models is examined.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 15:25:27 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Costa",
"Andrea",
""
],
[
"Gonzalez",
"Rafael",
""
]
] |
0706.1068 | Edmundo Castillo | Edmundo Castillo and Rafael Diaz | Rota-Baxter Categories | 32 pages, 9 figures | Int. Electron. J. Algebra 5 (2009) 27-57 | null | null | math.CT math.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce Rota-Baxter categories and construct examples of such
structures.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:33:49 GMT"
},
{
"version": "v2",
"created": "Mon, 11 Jun 2007 16:58:29 GMT"
},
{
"version": "v3",
"created": "Sun, 26 Oct 2008 17:45:58 GMT"
},
{
"version": "v4",
"created": "Tue, 3 Feb 2009 20:21:07 GMT"
}
] | 2009-02-03T00:00:00 | [
[
"Castillo",
"Edmundo",
""
],
[
"Diaz",
"Rafael",
""
]
] |
0706.1069 | Christoph Puetter | Christoph Puetter, Hyeonjin Doh, Hae-Young Kee | Meta-nematic transitions in a bilayer system: Application to the bilayer
ruthenate | 8 pages, 6 figures | Phys. Rev. B 76, 235112 (2007) | 10.1103/PhysRevB.76.235112 | null | cond-mat.str-el cond-mat.mtrl-sci | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It was suggested that the two consecutive metamagnetic transitions and the
large residual resistivity discovered in Sr$_3$Ru$_2$O$_7$ can be understood
via the nematic order and its domains in a single layer system. However, a
recently reported anisotropy between two longitudinal resistivities induced by
tilting the magnetic field away from the c-axis cannot be explained within the
single layer nematic picture. To fill the gap in our understanding within the
nematic order scenario, we investigate the effects of bilayer coupling and
in-plane magnetic field on the electronic nematic phases in a bilayer system.
We propose that the in-plane magnetic field in the bilayer system modifies the
energetics of the domain formation, since it breaks the degeneracy of two
different nematic orientations. Thus the system reveals a pure nematic phase
with a resistivity anisotropy in the presence of an in-plane magnetic field. In
addition to the nematic phase, the bilayer coupling opens a novel route to a
hidden nematic phase that preserves the x-y symmetry of the Fermi surfaces.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:41:46 GMT"
},
{
"version": "v2",
"created": "Tue, 16 Oct 2007 21:22:56 GMT"
},
{
"version": "v3",
"created": "Sun, 17 Aug 2008 18:39:41 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Puetter",
"Christoph",
""
],
[
"Doh",
"Hyeonjin",
""
],
[
"Kee",
"Hae-Young",
""
]
] |
0706.1070 | Kim Nilsson | Kim K. Nilsson (1,2), P. Moeller (1), O. Moeller (3), J.P.U. Fynbo
(2), M.J. Michalowski (2), D. Watson (2), C. Ledoux (4), P. Rosati (1), K.
Pedersen (2) and L.F. Grove (2), ((1) ESO-Garching, (2) Dark Cosmology
Centre, (3) MPA, (4) ESO-Chile) | A multi-wavelength study of z = 3.15 Lyman-alpha emitters in the GOODS
South Field | 13 pages, 14 figures, 8 tables, Accepted for publication in A&A | Astron.Astrophys. 471 (2007) 71-82 | 10.1051/0004-6361:20066949 | null | astro-ph | null | Context: Ly-alpha-emitters have proven to be excellent probes of faint,
star-forming galaxies in the high redshift universe. However, although the
sample of known emitters is increasingly growing, their nature (e.g. stellar
masses, ages, metallicities, star-formation rates) is still poorly constrained.
Aims: We aim to study the nature of Ly-alpha-emitters, to find the properties
of a typical Ly-alpha-emitting galaxy and to compare these properties with the
properties of other galaxies at similar redshift, in particular Lyman-break
galaxies.
Methods: We have performed narrow-band imaging at the VLT, focused on
Ly-alpha at redshift z ~ 3.15, in the GOODS-S field. We have identified a
sample of Ly-alpha-emitting candidates, and we have studied their Spectral
Energy Distributions (SEDs).
Results: We find that the emitters are best fit by an SED with low
metallicity (Z/Z_sun = 0.005), low dust extinction (A_V ~ 0.32) and medium
stellar masses of approximately 10^9 M_sun. The age is not very well
constrained. One object out of 24 appears to be a high redshift
Ly-alpha-emitting dusty starburst galaxy. We find filamentary structure as
traced by the Ly-alpha-emitters at the 4 sigma level. The rest-frame UV SED of
these galaxies is very similar to that of Lyman Break Galaxies (LBGs) and
comply with the selection criteria for U-band drop-outs, except they are
intrinsically fainter than the current limit for LBGs.
Conclusion: Ly-alpha-emitters are excellent probes of galaxies in the distant
universe, and represent a class of star-forming, dust and AGN free, medium mass
objects.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:15:34 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Nilsson",
"Kim K.",
""
],
[
"Moeller",
"P.",
""
],
[
"Moeller",
"O.",
""
],
[
"Fynbo",
"J. P. U.",
""
],
[
"Michalowski",
"M. J.",
""
],
[
"Watson",
"D.",
""
],
[
"Ledoux",
"C.",
""
],
[
"Rosati",
"P.",
""
],
[
"Pedersen",
"K.",
""
],
[
"Grove",
"L. F.",
""
]
] |
0706.1071 | Lam Hui | Lam Hui, Enrique Gaztanaga and Marilena LoVerde | Anisotropic Magnification Distortion of the 3D Galaxy Correlation: I.
Real Space | 15 pages, revised to include a discussion of the pioneering paper by
Matsubara (2000) | Phys.Rev.D76:103502,2007 | 10.1103/PhysRevD.76.103502 | null | astro-ph | null | It is well known gravitational lensing, mainly via magnification bias,
modifies the observed galaxy/quasar clustering. Such discussions have largely
focused on the 2D angular correlation. Here and in a companion paper (Paper II)
we explore how magnification bias distorts the 3D correlation function and
power spectrum, as first considered by Matsubara. The interesting point is: the
distortion is anisotropic. Magnification bias preferentially enhances the
observed correlation in the line-of-sight (LOS) orientation, especially on
large scales. For example at LOS separation of ~100 Mpc/h, where the intrinsic
galaxy-galaxy correlation is rather weak, the observed correlation can be
enhanced by lensing by a factor of a few, even at a modest redshift of z ~
0.35. The opportunity: this lensing anisotropy is distinctive, making it
possible to separately measure the galaxy-galaxy, galaxy-magnification and
magnification-magnification correlations, without measuring galaxy shapes. The
anisotropy is distinguishable from the well known distortion due to peculiar
motions, as will be discussed in Paper II. The challenge: the magnification
distortion of the galaxy correlation must be accounted for in interpreting data
as precision improves. For instance, the ~100 Mpc/h baryon acoustic oscillation
scale in the correlation function is shifted by up to ~3% in the LOS
orientation, and up to ~0.6% in the monopole, depending on the galaxy bias,
redshift and number count slope. The corresponding shifts in the inferred
Hubble parameter and angular diameter distance, if ignored, could significantly
bias measurements of the dark energy equation of state. Lastly, magnification
distortion offers a plausible explanation for the well known excess
correlations seen in pencil beam surveys.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 02:46:42 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 05:14:49 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hui",
"Lam",
""
],
[
"Gaztanaga",
"Enrique",
""
],
[
"LoVerde",
"Marilena",
""
]
] |
0706.1072 | Max Lieblich | Daniel Krashen and Max Lieblich | Index reduction for Brauer classes via stable sheaves (with an appendix
by Bhargav Bhatt) | 18 pages. Additional minor revisions and corrections | Int. Math. Res. Not. IMRN 2008, no. 8, Art. ID rnn010, 31 pp | null | null | math.AG math.RA | null | We use twisted sheaves to study the problem of index reduction for Brauer
classes. In general terms, this problem may be phrased as follows: given a
field $k$, a $k$-variety $X$, and a class $\alpha \in \Br(k)$, compute the
index of the class $\alpha_{k(X)} \in \Br(X)$ obtained from $\alpha$ by
extension of scalars to $k(X)$. We give a general method for computing index
reduction which refines classical results of Schofield and van den Bergh. When
$X$ is a curve of genus 1, we use Atiyah's theorem on the structure of stable
vector bundles with integral slope to show that our formula simplifies
dramatically, giving a complete solution to the index reduction problem in this
case. Using the twisted Fourier-Mukai transform, we show that a similarly
simple formula describes homogeneous index reduction on torsors under
higher-dimensional abelian varieties.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:13:57 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jul 2007 19:11:44 GMT"
},
{
"version": "v3",
"created": "Wed, 26 Dec 2007 20:09:28 GMT"
}
] | 2018-06-18T00:00:00 | [
[
"Krashen",
"Daniel",
""
],
[
"Lieblich",
"Max",
""
]
] |
0706.1073 | Renato A. Dupke | Renato A. Dupke, Nestor Mirabal, Joel N. Bregman and August E. Evrard | The Merger in Abell 576: A Line of Sight Bullet Cluster? | 24 pages, 2 tables and 20 figures; accepted for publication in the
Astrophysical Journal. For full version with all figures click on
http://www.astro.lsa.umich.edu/~rdupke/a576_web.pdf | null | 10.1086/520708 | null | astro-ph | null | Using a combination of Chandra and XMM observations, we confirmed the
presence of a significant velocity gradient along the NE/E-W/SW direction in
the intracluster gas of the cluster Abell 576. The results are consistent with
a previous ASCA SIS analysis of this cluster. The error weighted average over
ACIS-S3, EPIC MOS 1 & 2 spectrometers for the maximum velocity difference is
>3.3E03 km/s at the 90% confidence level, similar to the velocity limits
estimated indirectly for the "bullet" cluster (1E0657-56). The probability that
the velocity gradient is generated by standard random gain fluctuations with
Chandra and XMM is <0.1%. The regions of maximum velocity gradient are in CCD
zones that have the lowest temporal gain variations. It is unlikely that the
velocity gradient is due to Hubble distance differences between projected
clusters (probability<~0.01%). We mapped the distribution of elemental
abundance ratios across the cluster and detected a strong chemical
discontinuity using the abundance ratio of silicon to iron, equivalent to a
variation from 100% SN Ia iron mass fraction in the West-Northwest regions to
32% in the Eastern region. The "center" of the cluster is located at the
chemical discontinuity boundary, which is inconsistent with the radially
symmetric chemical gradient found in some regular clusters, but consistent with
a cluster merging scenario. We predict that the velocity gradient as measured
will produce a variation of the CMB temperature towards the East of the core of
the cluster that will be detectable by current and near-future bolometers. The
measured velocity gradient opens for the possibility that this cluster is
passing through a near line-of-sight merger stage where the cores have recently
crossed.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 00:37:39 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Dupke",
"Renato A.",
""
],
[
"Mirabal",
"Nestor",
""
],
[
"Bregman",
"Joel N.",
""
],
[
"Evrard",
"August E.",
""
]
] |
0706.1074 | Nicholas Sterling | N. C. Sterling (1) and Harriet L. Dinerstein (2) ((1) NASA Goddard
Space Flight Center; (2) University of Texas at Austin) | The Abundances of Light Neutron-Capture Elements in Planetary Nebulae
II. s-process Enrichments and Interpretation | 105 pages, including 19 tables and 9 figures. Accepted for
publication in ApJS | null | 10.1086/511031 | null | astro-ph | null | We present the results of a large-scale survey of neutron(n)-capture elements
in Galactic planetary nebulae (PNe), undertaken to study enrichments from
s-process nucleosynthesis in their progenitor stars. From new K band
observations of over 100 PNe supplemented by data from the literature, we have
detected the emission lines [Kr III] 2.199 and/or [Se IV] 2.287 $\mu$m in 81 of
120 objects. We determine Se and Kr elemental abundances, employing ionization
correction formulae derived in the first paper of this series. We find a
significant range in Se and Kr abundances, from near solar (no enrichment) to
enhanced by >1.0 dex relative to solar, which we interpret as self-enrichment
due to in situ s-process nucleosynthesis. Kr tends to be more strongly enriched
than Se; in 18 objects exhibiting both Se and Kr emission, we find that [Kr/Se]
= 0.5$\pm$0.2.
Our survey has increased the number of PNe with n-capture element abundance
determinations by a factor of ten, enabling us for the first time to search for
correlations with other nebular properties. As expected, we find a positive
correlation between s-process enrichments and the C/O ratio. Type I and bipolar
PNe, which arise from intermediate-mass progenitors (>3-4 solar masses),
exhibit little to no s-process enrichments. Finally, PNe with H-deficient
Wolf-Rayet central stars do not exhibit systematically larger s-process
enrichments than objects with H-rich nuclei. Overall, 44% of the PNe in our
sample display significant s-process enrichments (>0.3 dex). Using an empirical
PN luminosity function to correct for incompleteness, we estimate that the true
fraction of s-process enriched Galactic PNe is at least 20%.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:16:37 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sterling",
"N. C.",
""
],
[
"Dinerstein",
"Harriet L.",
""
]
] |
0706.1075 | Michael Reimer E | Michael E. Reimer, Marek Korkusinski, Jacques Lefebvre, Jean Lapointe,
Philip J. Poole, Geof C. Aers, Dan Dalacu, W. Ross McKinnon, Simon Frederick,
Pawel Hawrylak, and Robin L. Williams | Voltage Induced Hidden Symmetry and Photon Entanglement Generation in a
Single, Site-Selected Quantum Dot | 4 pages, 4 figures submitted to Physical Review Letters | null | null | null | quant-ph | null | Present proposals for the realisation of entangled photon pair sources using
the radiative decay of the biexciton in semiconductor quantum dots are limited
by the need to enforce degeneracy of the two intermediate, single exciton
states. We show how this requirement is lifted if the biexciton binding energy
can be tuned to zero and we demonstrate this unbinding of the biexciton in a
single, pre-positioned InAs quantum dot subject to a lateral electric field.
Full Configuration-Interaction calculations are presented that reveal how the
biexciton is unbound through manipulation of the electron-hole Coulomb
interaction and the consequent introduction of Hidden Symmetry.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:23:22 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Reimer",
"Michael E.",
""
],
[
"Korkusinski",
"Marek",
""
],
[
"Lefebvre",
"Jacques",
""
],
[
"Lapointe",
"Jean",
""
],
[
"Poole",
"Philip J.",
""
],
[
"Aers",
"Geof C.",
""
],
[
"Dalacu",
"Dan",
""
],
[
"McKinnon",
"W. Ross",
""
],
[
"Frederick",
"Simon",
""
],
[
"Hawrylak",
"Pawel",
""
],
[
"Williams",
"Robin L.",
""
]
] |
0706.1076 | Sebastien Heinis | Sebastien Heinis, Bruno Milliard, Stephane Arnouts, Jeremy Blaizot,
David Schiminovich, Tamas Budavari, Olivier Ilbert, Marie Treyer, Ted K.
Wyder, Henry J. McCracken, Tom A. Barlow, Karl Forster, Peter G. Friedman, D.
Christopher Martin, Patrick Morrissey, Susan G. Neff, Mark Seibert, Todd
Small, Luciana Bianchi, Timothy M. Heckman, Young-Wook Lee, Barry F. Madore,
R. Michael Rich, Alex S. Szalay, Barry Y. Welsh, Sukyoung K. Yi and C. K. Xu | Clustering Properties of restframe UV selected galaxies II: Migration of
Star Formation sites with cosmic time from GALEX and CFHTLS | Accepted for Publication in the Special GALEX Ap. J. Supplement,
December 2007 Version with full resolution fig1 available at
http://taltos.pha.jhu.edu/~sebastien/papers/Galex_p2.ps.gz | null | 10.1086/520580 | null | astro-ph | null | We analyze the clustering properties of ultraviolet selected galaxies by
using GALEX-SDSS data at z<0.6 and CFHTLS deep u' imaging at z=1. These
datasets provide a unique basis at z< 1 which can be directly compared with
high redshift samples built with similar selection criteria. We discuss the
dependence of the correlation function parameters (r0, delta) on the
ultraviolet luminosity as well as the linear bias evolution. We find that the
bias parameter shows a gradual decline from high (b > 2) to low redshift (b ~
0.79^{+0.1}_{-0.08}). When accounting for the fraction of the star formation
activity enclosed in the different samples, our results suggest that the bulk
of star formation migrated from high mass dark matter halos at z>2 (10^12 <
M_min < 10^13 M_sun, located in high density regions), to less massive halos at
low redshift (M_min < 10^12 M_sun, located in low density regions). This result
extends the ``downsizing'' picture (shift of the star formation activity from
high stellar mass systems at high z to low stellar mass at low z) to the dark
matter distribution.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:26:32 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Heinis",
"Sebastien",
""
],
[
"Milliard",
"Bruno",
""
],
[
"Arnouts",
"Stephane",
""
],
[
"Blaizot",
"Jeremy",
""
],
[
"Schiminovich",
"David",
""
],
[
"Budavari",
"Tamas",
""
],
[
"Ilbert",
"Olivier",
""
],
[
"Treyer",
"Marie",
""
],
[
"Wyder",
"Ted K.",
""
],
[
"McCracken",
"Henry J.",
""
],
[
"Barlow",
"Tom A.",
""
],
[
"Forster",
"Karl",
""
],
[
"Friedman",
"Peter G.",
""
],
[
"Martin",
"D. Christopher",
""
],
[
"Morrissey",
"Patrick",
""
],
[
"Neff",
"Susan G.",
""
],
[
"Seibert",
"Mark",
""
],
[
"Small",
"Todd",
""
],
[
"Bianchi",
"Luciana",
""
],
[
"Heckman",
"Timothy M.",
""
],
[
"Lee",
"Young-Wook",
""
],
[
"Madore",
"Barry F.",
""
],
[
"Rich",
"R. Michael",
""
],
[
"Szalay",
"Alex S.",
""
],
[
"Welsh",
"Barry Y.",
""
],
[
"Yi",
"Sukyoung K.",
""
],
[
"Xu",
"C. K.",
""
]
] |
0706.1077 | Jordan Goblet | Jordan Goblet and Wei Zhu | Regularity of Dirichlet nearly minimizing multiple-valued functions | 25 pages + 2 figures | null | null | null | math.AP | null | In this paper, we extend the related notions of Dirichlet quasiminimizer,
$\omega-$minimizer and almost minimizer to the framework of multiple-valued
functions in the sense of Almgren and prove Holder regularity results. We also
give examples of those minimizers with various branch sets.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:26:50 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Goblet",
"Jordan",
""
],
[
"Zhu",
"Wei",
""
]
] |
0706.1078 | Mary Manning | M. L. Manning, J. S. Langer, and J. M. Carlson | Strain localization in a shear transformation zone model for amorphous
solids | 8 figures, references added, typos corrected | null | 10.1103/PhysRevE.76.056106 | null | cond-mat.soft cond-mat.mtrl-sci | null | We model a sheared disordered solid using the theory of Shear Transformation
Zones (STZs). In this mean-field continuum model the density of zones is
governed by an effective temperature that approaches a steady state value as
energy is dissipated. We compare the STZ model to simulations by Shi, et
al.(Phys. Rev. Lett. 98 185505 2007), finding that the model generates
solutions that fit the data,exhibit strain localization, and capture important
features of the localization process. We show that perturbations to the
effective temperature grow due to an instability in the transient dynamics, but
unstable systems do not always develop shear bands. Nonlinear energy
dissipation processes interact with perturbation growth to determine whether a
material exhibits strain localization. By estimating the effects of these
interactions, we derive a criterion that determines which materials exhibit
shear bands based on the initial conditions alone. We also show that the shear
band width is not set by an inherent diffusion length scale but instead by a
dynamical scale that depends on the imposed strain rate.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:32:12 GMT"
},
{
"version": "v2",
"created": "Thu, 14 Jun 2007 00:55:45 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Manning",
"M. L.",
""
],
[
"Langer",
"J. S.",
""
],
[
"Carlson",
"J. M.",
""
]
] |
0706.1079 | Benjamin Collins | Benjamin F. Collins, Re'em Sari | Co-orbital Oligarchy | 10 pages, 8 figures. v2 includes major revisions including additional
results motivated by the referee's comments | null | 10.1088/0004-6256/137/4/3778 | null | astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a systematic examination of the changes in semi-major axis caused
by the mutual interactions of a group of massive bodies orbiting a central star
in the presence of eccentricity dissipation. For parameters relevant to the
oligarchic stage of planet formation, dynamical friction keeps the typical
eccentricities small and prevents orbit crossing. Interactions at impact
parameters greater than several Hill radii cause the protoplanets to repel each
other; if the impact parameter is instead much less than the Hill radius, the
protoplanets shift slightly in semi-major axis but remain otherwise
unperturbed. If the orbits of two or more protoplanets are separated by less
than a Hill radius, they are each pushed towards an equilibrium spacing between
their neighbors and can exist as a stable co-orbital system. In the
shear-dominated oligarchic phase of planet formation we show that the feeding
zones contain several oligarchs instead of only one. Growth of the protoplanets
in the oligarchic phase drives the disk to an equilibrium configuration that
depends on the mass ratio of protoplanets to planetesimals, $\Sigma/\sigma$.
Early in the oligarchic phase, when $\Sigma/\sigma$ is low, the spacing between
rows of co-orbital oligarchs are about 5 Hill radii wide, rather than the 10
Hill radii cited in the literature. It is likely that at the end of oligarchy
the average number of co-orbital oligarchs is greater than unity. In the outer
solar system this raises the disk mass required to form the ice giants. In the
inner solar system this lowers the mass of the final oligarchs and requires
more giant impacts than previously estimated. This result provides additional
evidence that Mars is not an untouched leftover from the oligarchic phase, but
must be composed of several oligarchs assembled through giant impacts.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:33:46 GMT"
},
{
"version": "v2",
"created": "Tue, 13 Jan 2009 02:03:25 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Collins",
"Benjamin F.",
""
],
[
"Sari",
"Re'em",
""
]
] |
0706.1080 | Matthias Brust R. | Matthias R. Brust, Adrian Andronache, Steffen Rothkugel | WACA: A Hierarchical Weighted Clustering Algorithm optimized for Mobile
Hybrid Networks | The Third International Conference on Wireless and Mobile
Communications 2007 | null | null | null | cs.DC cs.NI | null | Clustering techniques create hierarchal network structures, called clusters,
on an otherwise flat network. In a dynamic environment-in terms of node
mobility as well as in terms of steadily changing device parameters-the
clusterhead election process has to be re-invoked according to a suitable
update policy. Cluster re-organization causes additional message exchanges and
computational complexity and it execution has to be optimized. Our
investigations focus on the problem of minimizing clusterhead re-elections by
considering stability criteria. These criteria are based on topological
characteristics as well as on device parameters. This paper presents a weighted
clustering algorithm optimized to avoid needless clusterhead re-elections for
stable clusters in mobile ad-hoc networks. The proposed localized algorithm
deals with mobility, but does not require geographical, speed or distances
information.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:47:19 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Brust",
"Matthias R.",
""
],
[
"Andronache",
"Adrian",
""
],
[
"Rothkugel",
"Steffen",
""
]
] |
0706.1081 | Robert R. Caldwell | P. P. Yu | The limiting behavior of the Liu-Yau quasi-local energy | 26 pages, latex | null | null | null | gr-qc | null | The small- and large-sphere limits of the quasi-local energy recently
proposed by Liu and Yau are carefully examined. It is shown that in the
small-sphere limit, the non-vacuum limit of the Liu-Yau quasi-local energy
approaches the expected value \frac{4\pi}{3} r^3 T(e_0, e_0)$. Here, T is the
energy-stress tensor of matter, e_0 \in T_p M is unit time-like and
future-directed at the point p located at the center of the small sphere of
radius $r$ in the limit r \to 0. In vacuum, however, the limiting value of the
Liu-Yau quasi-local energy contains the desired limit \frac{r^5}{90} B(e_0,
e_0, e_0, e_0), where B is the Bel-Robinson tensor, as well as an extra term.
In the large-sphere limit at null infinity, for isolated gravitational sources,
the Liu-Yau quasi-local energy is shown to recover the Bondi mass and Bondi
news flux, in space-times that are asymptotically empty and flat at null
infinity. The physical validity of the Liu-Yau model in view of these results
is discussed.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:49:14 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Yu",
"P. P.",
""
]
] |
0706.1082 | Alfredo Suzuki T | Alfredo Takashi Suzuki | Analytic result for the one-loop massless triangle Feynman diagram | Added reference 4 pages, 1 figure Extended abstract, added reference,
added figure with caption, 5 pages, 2 figures | null | null | null | hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Different mathematical methods have been applied to obtain the analytic
result for the massless triangle Feynman diagram yielding a sum of four
linearly independent hypergeometric functions $F_4$. In this paper I work out
the diagram and show that that result, though mathematically sound, is not
physically correct, because it misses a fundamental physical constraint imposed
by the conservation of momentum, which should reduce by one the total number of
linearly independent (l.i.) functions $F_4$ in the overall solution. Taking
into account that the momenta flowing along the three legs of the diagram are
constrained by momentum conservation, the number of overall l.i. functions that
enter the most general solution must reduce accordingly.
To determine the exact structure and content of the analytic solution for the
three-point function, I use the analogy that exists between Feynman diagrams
and electric circuit networks, in which the electric current flowing in the
network plays the role of the momentum flowing in the lines of a Feynman
diagram. This analogy is employed to define exactly which three out of the four
hypergeometric functions are relevant to the analytic solution for the Feynman
diagram. The analogy is built based on the equivalence between electric
resistance circuit networks of type "Y" and "Delta" in which flows a conserved
current. The equivalence is established via the theorem of minimum energy
dissipation within circuits having these structures.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:49:43 GMT"
},
{
"version": "v2",
"created": "Tue, 16 Oct 2007 02:52:06 GMT"
},
{
"version": "v3",
"created": "Tue, 12 Aug 2008 12:43:32 GMT"
}
] | 2008-08-12T00:00:00 | [
[
"Suzuki",
"Alfredo Takashi",
""
]
] |
0706.1083 | Laura Brenneman | L.W. Brenneman (1), C.S. Reynolds (1), J. Wilms (2), M.E. Kaiser (3)
((1) Dept. of Astronomy, University of Maryland, College Park; (2) University
of Erlangen-Nuremburg; (3) Dept. of Physics and Astronomy, Johns Hopkins
University) | An X-ray Spectral Analysis of the Central Regions of NGC 4593 | Accepted for publication by ApJ, 6/6/07 | Astrophys.J.666:817-827,2007 | 10.1086/520763 | null | astro-ph | null | We present a detailed analysis of XMM-Newton EPIC-pn data for the Seyfert-1
galaxy NGC 4593. We discuss the X-ray spectral properties of this source as
well as its variations with time. The 0.5-10 keV spectrum shows significant
complexity beyond a simple power-law form, with clear evidence existing for a
"soft excess" as well as absorption by highly ionized plasma (a warm absorber)
within the central engine of this active galactic nucleus. We show that the
soft excess is best described as originating from thermal Comptonization by
plasma that is appreciably cooler than the primary X-ray emitting plasma; we
find that the form of the soft excess cannot be reproduced adequately by
reflection from an ionized accretion disk. The only measurable deviation from
the power-law continuum in the hard spectrum comes from the presence of cold
and ionized fluorescent iron-K emission lines at 6.4 and 6.97 keV,
respectively. While constraints on the ionized iron line are weak, the cold
line is found to be narrow at CCD-resolution with a flux that does not track
the temporal changes in the underlying continuum, implying an origin in the
outer radii of the accretion disk or the putative molecular torus of Seyfert
unification schemes. The X-ray continuum itself varies on all accessible time
scales. We detect a ~230-second time-lag between soft and hard EPIC-pn bands
that, if interpreted as scattering timescales within a Comptonizing disk
corona, can be used to constrain the physical size of the primary X-ray source
to a characteristic length scale of ~2 gravitational radii. Taken together, the
small implied coronal size and the large implied iron line emitting region
indicate a departure from the current picture of a "typical" AGN geometry.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 20:57:30 GMT"
}
] | 2011-02-11T00:00:00 | [
[
"Brenneman",
"L. W.",
""
],
[
"Reynolds",
"C. S.",
""
],
[
"Wilms",
"J.",
""
],
[
"Kaiser",
"M. E.",
""
]
] |
0706.1084 | Adam D. Smith | Sofya Raskhodnikova and Dana Ron and Ronitt Rubinfeld and Adam Smith | Sublinear Algorithms for Approximating String Compressibility | To appear in the proceedings of RANDOM 2007 | null | null | null | cs.DS | null | We raise the question of approximating the compressibility of a string with
respect to a fixed compression scheme, in sublinear time. We study this
question in detail for two popular lossless compression schemes: run-length
encoding (RLE) and Lempel-Ziv (LZ), and present sublinear algorithms for
approximating compressibility with respect to both schemes. We also give
several lower bounds that show that our algorithms for both schemes cannot be
improved significantly.
Our investigation of LZ yields results whose interest goes beyond the initial
questions we set out to study. In particular, we prove combinatorial structural
lemmas that relate the compressibility of a string with respect to Lempel-Ziv
to the number of distinct short substrings contained in it. In addition, we
show that approximating the compressibility with respect to LZ is related to
approximating the support size of a distribution.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 02:58:28 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Raskhodnikova",
"Sofya",
""
],
[
"Ron",
"Dana",
""
],
[
"Rubinfeld",
"Ronitt",
""
],
[
"Smith",
"Adam",
""
]
] |
0706.1085 | Danny Marfatia | V. Barger, D. Marfatia, K. Whisnant | Challenging Lorentz noninvariant neutrino oscillations without neutrino
masses | 19 pages, 6 figures, 1 table. Version to appear in PLB | Phys.Lett.B653:267-277,2007 | 10.1016/j.physletb.2007.07.047 | null | hep-ph hep-ex | null | We show that the combined data from solar, long-baseline and reactor neutrino
experiments can exclude the generalized bicycle model of Lorentz noninvariant
direction-dependent and/or direction-independent oscillations of massless
neutrinos. This model has five parameters, which is more than is needed in
standard oscillation phenomenology with neutrino masses. Solar data alone are
sufficient to exclude the pure direction-dependent case. The combination of
solar and long-baseline data rules out the pure direction-independent case.
With the addition of KamLAND data, a mixture of direction-dependent and
direction-independent terms in the effective Hamiltonian is also excluded.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 19:11:51 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Jul 2007 17:11:37 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Barger",
"V.",
""
],
[
"Marfatia",
"D.",
""
],
[
"Whisnant",
"K.",
""
]
] |
0706.1086 | Massimo Turatto | M. Turatto, S. Benetti, A. Pastorello | Supernova Classes and Subclasses | 10 pages, 2 figure, review for "Supernova 1987A: 20 Years After:
Supernovae and Gamma-Ray Bursters" AIP, New York, eds. S. Immler, K.W.
Weiler, and R. McCray | AIPConf.Proc.937:187-197,2007 | 10.1063/1.2803562 | null | astro-ph | null | The discovery of many objects with unprecedented, amazing observational
characteristics caused the last decade to be the most prolific period for the
supernova research. Many of these new supernovae are transitional objects
between existing classes, others well enter within the defined classes, but
still show unique properties. This makes the traditional classification scheme
inadequate to take into account the overall SN variety and, consequently,
requires the introduction of new subclasses.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 15:29:45 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Turatto",
"M.",
""
],
[
"Benetti",
"S.",
""
],
[
"Pastorello",
"A.",
""
]
] |
0706.1087 | Matthias Brust R. | Matthias R. Brust, Steffen Rothkugel | On Anomalies in Annotation Systems | The Third International Workshop on E-learning and Mobile Learning on
Telecommunications (ELETE 2007) | null | null | null | cs.HC cs.CY | null | Today's computer-based annotation systems implement a wide range of
functionalities that often go beyond those available in traditional
paper-and-pencil annotations. Conceptually, annotation systems are based on
thoroughly investigated psycho-sociological and pedagogical learning theories.
They offer a huge diversity of annotation types that can be placed in textual
as well as in multimedia format. Additionally, annotations can be published or
shared with a group of interested parties via well-organized repositories.
Although highly sophisticated annotation systems exist both conceptually as
well as technologically, we still observe that their acceptance is somewhat
limited. In this paper, we argue that nowadays annotation systems suffer from
several fundamental problems that are inherent in the traditional
paper-and-pencil annotation paradigm. As a solution, we propose to shift the
annotation paradigm for the implementation of annotation system.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 21:23:40 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Brust",
"Matthias R.",
""
],
[
"Rothkugel",
"Steffen",
""
]
] |
0706.1088 | Alexander Panchenko | Alexander Panchenko | G-convergence and homogenization of viscoelastic flows | null | null | null | null | math.AP math-ph math.MP | null | The paper is devoted to homogenization of two-phase incompressible
viscoelastic flows with disordered microstructure. We study two cases. In the
first case, both phases are modeled as Kelvin-Voight viscoelastic materials. In
the second case, one phase is a Kelvin-Voight material, and the other is a
viscous Newtonian fluid. The microscale system contains the conservation of
mass and balance of momentum equations. The inertial terms in the momentum
equation incorporate the actual interface advected by the flow. In the
constitutive equations, a frozen interface is employed. The interface geometry
is arbitrary: we do not assume periodicity, statistical homogeneity or scale
separation. The problem is homogenized using G-convergence and oscillating test
functions. Since the microscale system is not parabolic, previously known
constructions of the test functions do not work here. The test functions
developed in the paper are non-local in time and satisfy divergence-free
constraint exactly. The latter feature enables us to avoid working with
pressure directly. We show that the effective medium is a single phase
viscoelastic material that is not necessarily of Kelvin-Voight type. The
effective constitutive equation contains a long memory viscoelastic term, as
well as instantaneous elastic and viscous terms.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 21:23:07 GMT"
},
{
"version": "v2",
"created": "Fri, 22 Jun 2007 21:18:37 GMT"
}
] | 2007-06-23T00:00:00 | [
[
"Panchenko",
"Alexander",
""
]
] |
0706.1089 | Xuezhao Bao | Xuezhao Bao and Ali Zhang | Geochemistry of U and Th and its Influence on the Origin and Evolution
of the Crust of Earth and the Biological Evolution | 18 pages, 3 figures, 2 tables. Language correction | ActaPetrolog.Mineral.17:160-172,1998 | null | null | physics.geo-ph astro-ph q-bio.PE | null | We have investigated the migration behaviors of uranium (U) and thorium (Th)
in Earth and other terrestrial planets. Theoretical models of U and Th
migration have been proposed. These models suggest that the unique features of
Earth are closely connected with its unique U and Th migration models and
distribution patterns. In the Earth, U and Th can combine with oxidative
volatile components and water, migrate up to the asthenosphere position to form
an enrichment zone (EZ) of U and Th first, and then migrate up further to the
crusts through magmatism and metamorphism. We emphasize that the formation of
an EZ of U, Th and other heat-producing elements is a prerequisite for the
formation of a plate tectonic system. The heat-producing elements, currently
mainly U and Th, in the EZ are also the energy sources that drive the formation
and evolution of the crust of Earth and create special granitic continental
crusts. In other terrestrial planets, including Mercury, Venus, and Mars, an EZ
can not be formed because of a lack of oxidative volatile components and water.
For this reason, a plate tectonic system can not been developed in these
planets. We also emphasize the influence of U and Th in EZ on the development
and evolution of life on Earth. We propose that since the Earth and planets
were born in a united solar system, there should be some common mechanisms to
create the similarities and differences between them. We have tried to develop
an integrated view to explain some problems in the tectonics of Earth and
evolution, bio-evolution, and planetary dynamics through U and Th geochemistry.
We believe that a comprehensive exploration on energy sources and their
evolution is a good way to build bridges between different disciplines of
science in order to better understand the Earth and planets.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 21:23:22 GMT"
},
{
"version": "v2",
"created": "Sat, 9 Jun 2007 12:30:29 GMT"
},
{
"version": "v3",
"created": "Tue, 12 Jun 2007 17:01:57 GMT"
},
{
"version": "v4",
"created": "Mon, 23 Jul 2007 03:45:26 GMT"
},
{
"version": "v5",
"created": "Wed, 15 Aug 2007 19:36:47 GMT"
},
{
"version": "v6",
"created": "Thu, 16 Aug 2007 04:49:51 GMT"
},
{
"version": "v7",
"created": "Mon, 10 Sep 2007 17:55:24 GMT"
},
{
"version": "v8",
"created": "Sat, 15 Sep 2007 17:17:36 GMT"
},
{
"version": "v9",
"created": "Tue, 16 Oct 2007 19:08:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bao",
"Xuezhao",
""
],
[
"Zhang",
"Ali",
""
]
] |
0706.1090 | Daniel F. V. James | Daniel F. V. James and Jonathan Jerke | Effective Hamiltonian Theory and Its Applications in Quantum Information | 5 pages, 3 figures, to be published in Canadian Journal of Physics | null | 10.1139/P07-060 | null | quant-ph | null | This paper presents a useful compact formula for deriving an effective
Hamiltonian describing the time-averaged dynamics of detuned quantum systems.
The formalism also works for ensemble-averaged dynamics of stochastic systems.
To illustrate the technique we give examples involving Raman processes,
Bloch-Siegert shifts and Quantum Logic Gates.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 21:23:39 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"James",
"Daniel F. V.",
""
],
[
"Jerke",
"Jonathan",
""
]
] |
0706.1091 | Boris Tsirelson | Boris Tsirelson | Some extremal problems related to Bell-type inequalities | 6 pages | null | null | null | math.CA | null | The best approximation by bounded product functions is calculated for some
very simple two-valued functions of two variables.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 15:36:16 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Tsirelson",
"Boris",
""
]
] |
0706.1092 | Martin Klazar | Vit Jelinek and Martin Klazar | Generalizations of Khovanskii's theorems on growth of sumsets in abelian
semigroups | 21 pages | null | null | null | math.CO math.NT | null | We show that if $P$ is a lattice polytope in the nonnegative orthant of
$\R^k$ and $\chi$ is a coloring of the lattice points in the orthant such that
the color $\chi(a+b)$ depends only on the colors $\chi(a)$ and $\chi(b)$, then
the number of colors of the lattice points in the dilation $nP$ of $P$ is for
large $n$ given by a polynomial (or, for rational $P$, by a quasipolynomial).
This unifies a classical result of Ehrhart and Macdonald on lattice points in
polytopes and a result of Khovanski\u\i{} on sumsets in semigroups. We also
prove a strengthening of multivariate generalizations of Khovanski\u\i's
theorem. Another result of Khovanski\u\i{} states that the size of the image of
a finite set after $n$ applications of mappings from a finite family of
mutually commuting mappings is for large $n$ a polynomial. We give a
combinatorial proof of a multivariate generalization of this theorem.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 22:29:11 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Jelinek",
"Vit",
""
],
[
"Klazar",
"Martin",
""
]
] |
0706.1093 | Maria Larraga | M. E. Larraga and L. Alvarez-Icaza | Cellular automata for traffic flow simulation with safety embedded
notions | 14 pages, 10 figures, Submitted | null | null | null | cond-mat.stat-mech | null | In this paper a cellular automata model for one-lane traffic flow is
presented. A new set of rules is proposed to better capture driver reactions to
traffic that are intended to preserve safety on the highway. As a result,
drivers behavior is derived from an analysis that determines the most
appropriate action for a vehicle based on the distance from the vehicle ahead
of it and the velocities of the two neighbor vehicles. The model preserves
simplicity of CA rules and at the same time makes the results closer to real
highway behavior. Simulation results exhibit the three states observed in real
traffic flow: Free-flow states, synchronized states, and stop-and-go states.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 22:30:15 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Larraga",
"M. E.",
""
],
[
"Alvarez-Icaza",
"L.",
""
]
] |
0706.1094 | Dean M. Townsley | D. M. Townsley (1), A. C. Calder (1,2), S. M. Asida (3), I. R.
Seitenzahl (1), F. Peng (1,4), N. Vladimirova (1), D. Q. Lamb (1), J. W.
Truran (1,5) ((1) U of Chicago, (2) SUNY StonyBrook, (3) Hebrew U, Jerusalem,
(4) Caltech, (5) Argonne) | Flame Evolution During Type Ia Supernovae and the Deflagration Phase in
the Gravitationally Confined Detonation Scenario | 14 pages, 10 figures, accepted to the Astrophysical Journal | null | 10.1086/521013 | null | astro-ph | null | We develop an improved method for tracking the nuclear flame during the
deflagration phase of a Type Ia supernova, and apply it to study the variation
in outcomes expected from the gravitationally confined detonation (GCD)
paradigm. A simplified 3-stage burning model and a non-static ash state are
integrated with an artificially thickened advection-diffusion-reaction (ADR)
flame front in order to provide an accurate but highly efficient representation
of the energy release and electron capture in and after the unresolvable flame.
We demonstrate that both our ADR and energy release methods do not generate
significant acoustic noise, as has been a problem with previous ADR-based
schemes. We proceed to model aspects of the deflagration, particularly the role
of buoyancy of the hot ash, and find that our methods are reasonably
well-behaved with respect to numerical resolution. We show that if a detonation
occurs in material swept up by the material ejected by the first rising bubble
but gravitationally confined to the white dwarf (WD) surface (the GCD
paradigm), the density structure of the WD at detonation is systematically
correlated with the distance of the deflagration ignition point from the center
of the star. Coupled to a suitably stochastic ignition process, this
correlation may provide a plausible explanation for the variety of nickel
masses seen in Type Ia Supernovae.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 22:52:56 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Townsley",
"D. M.",
""
],
[
"Calder",
"A. C.",
""
],
[
"Asida",
"S. M.",
""
],
[
"Seitenzahl",
"I. R.",
""
],
[
"Peng",
"F.",
""
],
[
"Vladimirova",
"N.",
""
],
[
"Lamb",
"D. Q.",
""
],
[
"Truran",
"J. W.",
""
]
] |
0706.1095 | Alexios P. Polychronakos | Alexios P. Polychronakos | Noncommutative Fluids | To appear in "Seminaire Poincare X", Institut Henri Poincare, Paris;
references added | null | 10.1007/978-3-7643-8522-4_3 | CCNY-HEP-07/6 | hep-th cond-mat.mes-hall math-ph math.MP physics.flu-dyn | null | We review the connection between noncommutative gauge theory, matrix models
and fluid mechanical systems. The noncommutative Chern-Simons description of
the quantum Hall effect and bosonization of collective fermion states are used
as specific examples.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 22:46:55 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 22:13:45 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Polychronakos",
"Alexios P.",
""
]
] |
0706.1096 | Matthias Brust R. | Matthias R. Brust, Steffen Rothkugel, Carlos H.C. Ribeiro | Inquiring the Potential of Evoking Small-World Properties for
Self-Organizing Communication Networks | null | Published in: Proceedings of 5th International Conference on
Networking (ICN 06), 2006, IEEE Computer Society Press | 10.1109/ICNICONSMCL.2006.124 | null | cs.NI | null | Mobile multi-hop ad hoc networks allow establishing local groups of
communicating devices in a self-organizing way. However, in a global setting
such networks fail to work properly due to network partitioning. Providing that
devices are capable of communicating both locally-e.g. using Wi-Fi or
Bluetooth-and additionally also with arbitrary remote devices-e.g. using
GSM/UMTS links-the objective is to find efficient ways of inter-linking
multiple network partitions. Tackling this problem of topology control, we
focus on the class of small-world networks that obey two distinguishing
characteristics: they have a strong local clustering while still retaining a
small average distance between two nodes. This paper reports on results gained
investigating the question if small-world properties are indicative for an
efficient link management in multiple multi-hop ad hoc network partitions.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 22:40:40 GMT"
},
{
"version": "v2",
"created": "Mon, 11 Jun 2007 05:34:49 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Brust",
"Matthias R.",
""
],
[
"Rothkugel",
"Steffen",
""
],
[
"Ribeiro",
"Carlos H. C.",
""
]
] |
0706.1097 | Pablo Alberca Bjerregaard | Pablo Alberca Bjerregaard and Candido Martin Gonzalez | Computational techniques for proving identities in symmetric
compositions | 19 pages | null | null | null | math.RA | null | We present in this work a complete session in a Mathematica notebook. The aim
of this notebook is to check identities in symmetric compositions. This
notebook is a complement of our work [1] and it has all the explicit
computations. We refer the reader to that paper which can be seen in
http://www.uibk.ac.at/mathematik/loos/jordan/index.html. First of all we will
present a few number of comands in order to simplify identities by extracting
scalars, SOut. The rest of the strategy holds on the powerfull of using
patterns and rules.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 23:03:27 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Bjerregaard",
"Pablo Alberca",
""
],
[
"Gonzalez",
"Candido Martin",
""
]
] |
0706.1098 | Chun-Yen Shen | Chang-Pao Chen, Hao-Wei Huang, and Chun-Yen Shen | Characterization of the matrix whose norm is determined by its action on
decreasing sequences | null | null | null | null | math.FA | null | Let $A=(a_{j,k})_{j,k \ge 1}$ be a non-negative matrix. In this paper, we
characterize those $A$ for which $\|A\|_{E, F}$ are determined by their actions
on decreasing sequences, where $E$ and $F$ are suitable normed Riesz spaces of
sequences.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 23:05:46 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Chen",
"Chang-Pao",
""
],
[
"Huang",
"Hao-Wei",
""
],
[
"Shen",
"Chun-Yen",
""
]
] |
0706.1099 | Chun-Yen Shen | Chun-Yen Shen | A slight improvement to Korenblum's constant | null | null | 10.1016/j.jmaa.2007.04.015 | null | math.CV | null | Let $A^2(D)$ be the Bergman space over the open unit disk $D$ in the complex
plane. Korenblum conjectured that there is an absolute constant $c \in (0,1)$
such that whenever $|f(z)|\le |g(z)|$ in the annulus $c<|z|<1$ then $||f(z)||
\le ||g(z)||$.In 2004 C.Wang gave an upper bound on $c$,that is, $c < 0.67795$,
and in 2006 A.Schuster gave a lower bound ,$c > 0.21 $ .In this paper we
slightly improve the upper bound for $c$.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 23:21:00 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Shen",
"Chun-Yen",
""
]
] |
0706.1100 | Shao-Long Chen | Shao-Long Chen, Xiao-Gang He, A. Hovhannisyan and Ho-Chin Tsai | SUSY R-parity violating contributions to the width differences for
$D-\bar{D}$ and $B_{d,s}-\bar B_{d,s}$ systems | 19 pages, 1 figure. submitted to JHEP | JHEP 0709:044,2007 | 10.1088/1126-6708/2007/09/044 | null | hep-ph | null | We study R-parity violating contributions to the mixing parameter $y$ for
$D^0 -\bar D^0$ and $B^0_{d,s} - \bar B^0_{d,s}$ systems. We first obtain
general expressions for new physics contributions to $y$ from effective four
fermion operators. We then use them to study R-parity contributions. We find
that R-parity violating contributions to $D^0 - \bar D^0$ mixing, and $B_{d}^0
- \bar B_{d}^0$ to be small. There may be sizable contribution to $B_s^0 -\bar
B_s^0$ mixing. We also obtain some interesting bounds on R-parity violating
parameters using known Standard Model predictions and experimental data.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 05:47:06 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Jul 2007 09:05:58 GMT"
},
{
"version": "v3",
"created": "Mon, 20 Aug 2007 03:41:06 GMT"
},
{
"version": "v4",
"created": "Thu, 30 Aug 2007 08:27:00 GMT"
}
] | 2009-01-06T00:00:00 | [
[
"Chen",
"Shao-Long",
""
],
[
"He",
"Xiao-Gang",
""
],
[
"Hovhannisyan",
"A.",
""
],
[
"Tsai",
"Ho-Chin",
""
]
] |
0706.1101 | Christian Remling | Christian Remling | The absolutely continuous spectrum of Jacobi matrices | (slightly) revised version | null | null | null | math.SP math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | I explore some consequences of a groundbreaking result of Breimesser and
Pearson on the absolutely continuous spectrum of one-dimensional Schr"odinger
operators. These include an Oracle Theorem that predicts the potential and
rather general results on the approach to certain limit potentials. In
particular, we prove a Denisov-Rakhmanov type theorem for the general finite
gap case.
The main theme is the following: It is extremely difficult to produce
absolutely continuous spectrum in one space dimension and thus its existence
has strong implications.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 00:58:37 GMT"
},
{
"version": "v2",
"created": "Wed, 11 Aug 2010 18:08:41 GMT"
}
] | 2010-08-12T00:00:00 | [
[
"Remling",
"Christian",
""
]
] |
0706.1102 | Piotr Szymczak | P. Szymczak and Marek Cieplak | Influence of Hydrodynamic Interactions on Mechanical Unfolding of
Proteins | to be published in Journal of Physics: Condensed Matter | null | 10.1088/0953-8984/19/28/285224 | null | q-bio.BM | null | We incorporate hydrodynamic interactions in a structure-based model of
ubiquitin and demonstrate that the hydrodynamic coupling may reduce the peak
force when stretching the protein at constant speed, especially at larger
speeds. Hydrodynamic interactions are also shown to facilitate unfolding at
constant force and inhibit stretching by fluid flows.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 01:04:03 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Szymczak",
"P.",
""
],
[
"Cieplak",
"Marek",
""
]
] |
0706.1103 | Pawel Pralat | Pawel Pralat, Jacques Verstraete, Nicholas Wormald | On the threshold for k-regular subgraphs of random graphs | null | null | null | null | math.CO math.PR | null | The $k$-core of a graph is the largest subgraph of minimum degree at least
$k$. We show that for $k$ sufficiently large, the $(k + 2)$-core of a random
graph $\G(n,p)$ asymptotically almost surely has a spanning $k$-regular
subgraph. Thus the threshold for the appearance of a $k$-regular subgraph of a
random graph is at most the threshold for the $(k+2)$-core. In particular, this
pins down the point of appearance of a $k$-regular subgraph in $\G(n,p)$ to a
window for $p$ of width roughly $2/n$ for large $n$ and moderately large $k$.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 01:18:32 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Pralat",
"Pawel",
""
],
[
"Verstraete",
"Jacques",
""
],
[
"Wormald",
"Nicholas",
""
]
] |
0706.1104 | Andrew Frey | Robert H. Brandenberger, Andrew R. Frey, Sugumi Kanno | Emergence of Fluctuations from a Tachyonic Big Bang | 8pg, RevTeX4, 1 fig, v2. added refs, v3. added small clarification, 1
ref | Phys.Rev.D76:083524,2007 | 10.1103/PhysRevD.76.083524 | null | hep-th astro-ph gr-qc hep-ph | null | It has recently been speculated that the end state of a collapsing universe
is a tachyonic big crunch. The time reversal of this process would be the
emergence of an expanding universe from a tachyonic big bang. In this
framework, we study the emergence of cosmological fluctuations. In particular,
we compare the amplitude of the perturbations at tne end of the tachyon phase
with what would be obtained assuming the usual vacuum initial conditions. We
find that cosmological fluctuations emerge in a thermal state. We comment on
the relation to the trans-Planckian problem of inflationary cosmology.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 01:22:11 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Jul 2007 03:12:22 GMT"
},
{
"version": "v3",
"created": "Sun, 19 Aug 2007 18:26:50 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Brandenberger",
"Robert H.",
""
],
[
"Frey",
"Andrew R.",
""
],
[
"Kanno",
"Sugumi",
""
]
] |
0706.1105 | Bruce Dawson | B.R. Dawson (for the Pierre Auger Collaboration) | Hybrid Performance of the Pierre Auger Observatory | Contribution to the 30th International Cosmic Ray Conference, Merida
Mexico, July 2007 | null | null | null | astro-ph | null | A key feature of the Pierre Auger Observatory is its hybrid design, in which
ultra high energy cosmic rays are detected simultaneously by fluorescence
telescopes and a ground array. The two techniques see air showers in
complementary ways, providing important cross-checks and measurement
redundancy. Much of the hybrid capability stems from the accurate geometrical
reconstruction it achieves, with accuracy better than either the ground array
detectors or a single telescope could achieve independently. We have studied
the geometrical and longitudinal profile reconstructions of hybrid events. We
present the results for the hybrid performance of the Observatory, including
trigger efficiency, energy and angular resolution, and the efficiency of the
event selection.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 01:41:42 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Dawson",
"B. R.",
"",
"for the Pierre Auger Collaboration"
]
] |
0706.1106 | Moshe Gai | M. Gai, D.N. McKinsey, K. Ni, D.A.R. Rubin, T. Wongjirad (Yale), R.
Alon, A. Breskin, M. Cortesi, J. Miyamoto, (Weizmann) | Toward Application of a Thick Gas Electron Multiplier (THGEM) Readout
for a Dark Matter Detector | To be published in the Proceedings of the 23rd Winter Workshop on
Nuclear Dynamics, Big Sky, Montana, February 11-18, 2007. This work is
supported by the Yale-Weizmann Collaboration Program of the American
Committee on Weizmann Institute of Science (ACWIS), New York | null | null | null | physics.ins-det astro-ph nucl-ex | null | The Yale-Weizmann collaboration aims to develop a low-radioactivity
(low-background) cryogenic noble liquid detector for Dark-Matter (DM) search in
measurements to be performed deep underground as for example carried out by the
XENON collaboration. A major issue is the background induced by natural
radioactivity of present-detector components including the Photo Multiplier
Tubes (PMT) made from glass with large U-Th content. We propose to use advanced
Thick Gaseous Electron Multipliers (THGEM) recently developed at the Weizmann
Institute of Science (WIS). These "hole-multipliers" will measure in a
two-phase (liquid/gas) Xe detector electrons extracted into the gas phase from
both ionization in the liquid as well as scintillation-induced photoelectrons
from a CsI photocathode immersed in LXe. We report on initial tests (in gas) of
THGEM made out of Cirlex (Kapton) which is well known to have low Ra-Th content
instead of the usual G10 material with high Ra-Th content.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 01:56:32 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Gai",
"M.",
"",
"Yale"
],
[
"McKinsey",
"D. N.",
"",
"Yale"
],
[
"Ni",
"K.",
"",
"Yale"
],
[
"Rubin",
"D. A. R.",
"",
"Yale"
],
[
"Wongjirad",
"T.",
"",
"Yale"
],
[
"Alon",
"R.",
""
],
[
"Breskin",
"A.",
""
],
[
"Cortesi",
"M.",
""
],
[
"Miyamoto",
"J.",
""
]
] |
0706.1107 | Ping Zhang | Zhigang Wang, Ping Zhang, Junren Shi | Orbital magnetization and its effect in antiferromagnets on the
distorted fcc lattice | 18 pages, 6 figures | null | 10.1103/PhysRevB.76.094406 | null | cond-mat.mes-hall cond-mat.str-el | null | We study the intrinsic orbital magnetization (OM) in antiferromagnets on the
distorted face-centered-cubic lattice. The combined lattice distortion and spin
frustration induce nontrivial $k$-space Chern invariant, which turns to result
in profound effects on the OM properties. We derive a specific relation between
the OM and the Hall conductivity, according to which it is found that the
intrinsic OM vanishes when the electron chemical potential lies in the Mott
gap. The distinct behavior of the intrinsic OM in the metallic and insulating
regions is shown. The Berry phase effects on the thermoelectric transport is
also discussed.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 02:14:36 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wang",
"Zhigang",
""
],
[
"Zhang",
"Ping",
""
],
[
"Shi",
"Junren",
""
]
] |
0706.1108 | Andrew Chubykalo | A. Chubykalo, A. Espinoza, R. Alvarado-Flores and A. Gutierrez
Rodriguez | Reply to `Comment on ``Helmholtz Theorem and the V-Gauge in the Problem
of Superluminal and Instantaneous Signals in Classical Electrodynamics" by A.
Chubykalo Et Al' by J. A. Heras [FOUND. Phys. Lett. vol. 19(6) p. 579 (2006)] | 5 pages, submitted to Foundations of Physics | null | 10.1007/s10701-007-9183-z | null | physics.gen-ph | null | This is the reply to `COMMENT ON ``HELMHOLTZ THEOREM AND THE V-GAUGE IN THE
PROBLEM OF SUPERLUMINAL AND INSTANTANEOUS SIGNALS IN CLASSICAL ELECTRODYNAMICS"
BY A. CHUBYKALO ET AL' BY J. A. HERAS [FOUND. PHYS. LETT. vol. 19(6) p. 579
(2006)]
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 02:28:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Chubykalo",
"A.",
""
],
[
"Espinoza",
"A.",
""
],
[
"Alvarado-Flores",
"R.",
""
],
[
"Rodriguez",
"A. Gutierrez",
""
]
] |
0706.1109 | Roy Kerr | Roy P. Kerr | Discovering the Kerr and Kerr-Schild metrics | 34 pages, 2 figures, cupbook.cls. To appear in "The Kerr Spacetime",
Eds D.L. Wiltshire, M. Visser and S.M. Scott, Cambridge Univ. Press | null | null | null | gr-qc | null | An historical account of the reasoning that led to the discovery of the Kerr
and Kerr-Schild metrics in 1963-1964, and their physical interpretation as
rotating black holes, is presented.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 04:21:18 GMT"
},
{
"version": "v2",
"created": "Mon, 14 Jan 2008 22:52:40 GMT"
}
] | 2008-01-15T00:00:00 | [
[
"Kerr",
"Roy P.",
""
]
] |
0706.1110 | Juergen Reichenbacher | Juergen Reichenbacher | Calculation of the Underground Muon Intensity Crouch Curve from a
Parameterization of the Flux at Surface | Contribution to the 30th International Cosmic Ray Conference, Merida
Mexico, 2007 (new version: DOE contract number DE-AC02-06CH11357 is
explicitly stated in acknowledgments now) | null | null | null | hep-ph | null | Utilizing only the vertical muon intensity of the Gaisser parameterization of
the muon flux at the surface and propagating this energy spectrum underground
according to statistical ionization and radiative energy losses, it is possible
to calculate the underground muon intensity Crouch curve. In addition, the
primary spectral index of the Gaisser parameterization can be adjusted from
$E^{-2.7}$ to $E^{-2.643}$ simply by minimizing the deviation from the Crouch
curve. For chemical compositions other than standard rock, the propagation of
the spectrum underground can be repeated with a different muon energy loss in
the material. The resulting underground muon intensity curve represents a
consistent conversion of the Crouch curve to the local rock, fully accounting
for the energy dependence of the muon $dE/dx$.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 18:23:14 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Reichenbacher",
"Juergen",
""
]
] |
0706.1111 | Joseph Kapusta | Joseph I. Kapusta and Todd Springer | Cosmological Black Hole Formation due to QCD and Electroweak Phase
Transitions | null | null | null | null | astro-ph | null | We solve dynamical equations of motion to determine the conditions under
which an over-dense region in the early universe will lead to collapse to a
black hole, starting from horizon crossing of the over-dense region to the
point of gravitational instability. Here we focus on the sensitivity to QCD and
electroweak phase transitions. We then solve rate equations to determine the
mass distribution of black holes in the present universe. A second order phase
transition or rapid crossover would have significant consequences only if the
index of primordial density fluctuations n > 1.25. However, a first order
transition would lead to a black hole dominated universe for any realistic
value of n including n=1.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 04:47:45 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Kapusta",
"Joseph I.",
""
],
[
"Springer",
"Todd",
""
]
] |
0706.1112 | A. M. Kamchatnov | G.A. El, A. Gammal, E.G. Khamis, R.A. Kraenkel, A.M. Kamchatnov | The theory of optical dispersive shock waves in photorefractive media | 26 pages | Phys. Rev. A 76, 053813 (2007) | 10.1103/PhysRevA.76.053813 | null | nlin.PS | null | The theory of optical dispersive shocks generated in propagation of light
beams through photorefractive media is developed. Full one-dimensional
analytical theory based on the Whitham modulation approach is given for the
simplest case of sharp step-like initial discontinuity in a beam with
one-dimensional strip-like geometry. This approach is confirmed by numerical
simulations which are extended also to beams with cylindrical symmetry. The
theory explains recent experiments where such dispersive shock waves have been
observed.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 04:15:59 GMT"
}
] | 2008-02-09T00:00:00 | [
[
"El",
"G. A.",
""
],
[
"Gammal",
"A.",
""
],
[
"Khamis",
"E. G.",
""
],
[
"Kraenkel",
"R. A.",
""
],
[
"Kamchatnov",
"A. M.",
""
]
] |
0706.1113 | Yusuke Arike | Yusuke Arike | Symmetric linear functions of the restricted quantum group
$\bar{U}_qsl_2(\mathbb{C})$ | 21 pages | null | null | null | math.QA | null | We determine a set of primitive idempotents and the basic algebra of the
restricted quantum group $\bar{U}_qsl_2(\mathbb{C})$. As a result, we can show
the dimension of the space of symmetric linear functions of
$\bar{U}_qsl_2(\mathbb{C})$ is $3p-1$
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 06:17:15 GMT"
}
] | 2007-06-11T00:00:00 | [
[
"Arike",
"Yusuke",
""
]
] |
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