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0704.2001 | Nabil Youssef L | M. I. Wanas, N. L. Youssef and A. M. Sid-Ahmed | Geometry of Parallelizable Manifolds in the Context of Generalized
Lagrange Spaces | 20 pages, LaTeX file, Presented in "The International Conference on
Finsler Extensions of Relativity Theory" held at Cairo, Egypt, November
4-10,2006. AMS Subject Classification: 53B40, 53A40, 53B50 (References have
been modified) | Balkan J. Geom. Appl., 13,2 (2008), 120-139. | null | null | gr-qc math.DG | null | In this paper, we deal with a generalization of the geometry of
parallelizable manifolds, or the absolute parallelism (AP-) geometry, in the
context of generalized Lagrange spaces. All geometric objects defined in this
geometry are not only functions of the positional argument $x$, but also depend
on the directional argument $y$. In other words, instead of dealing with
geometric objects defined on the manifold $M$, as in the case of classical
AP-geometry, we are dealing with geometric objects in the pullback bundle
$\pi^{-1}(TM)$ (the pullback of the tangent bundle $TM$ by $ \pi: T
M\longrightarrow M$). Many new geometric objects, which have no counterpart in
the classical AP-geometry, emerge in this more general context. We refer to
such a geometry as generalized AP-geometry (GAP-geometry). In analogy to
AP-geometry, we define a $d$-connection in $\pi^{-1}(TM)$ having remarkable
properties, which we call the canonical $d$-connection, in terms of the unique
torsion-free Riemannian $d$-connection. In addition to these two
$d$-connections, two more $d$-connections are defined, the dual and the
symmetric $d$-connections. Our space, therefore, admits twelve curvature
tensors (corresponding to the four defined $d$-connections), three of which
vanish identically. Simple formulae for the nine non-vanishing curvatures
tensors are obtained, in terms of the torsion tensors of the canonical
$d$-connection. The different $W$-tensors admitted by the space are also
calculated. All contractions of the $h$- and $v$-curvature tensors and the
$W$-tensors are derived. Second rank symmetric and skew-symmetric tensors,
which prove useful in physical applications, are singled out.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 12:26:25 GMT"
},
{
"version": "v2",
"created": "Fri, 30 Nov 2007 17:09:33 GMT"
}
] | 2008-05-02T00:00:00 | [
[
"Wanas",
"M. I.",
""
],
[
"Youssef",
"N. L.",
""
],
[
"Sid-Ahmed",
"A. M.",
""
]
] |
0704.2002 | Alexander Schekochihin | A. A. Schekochihin (Imperial), A. B. Iskakov (UCLA), S. C. Cowley
(UCLA), J. C. McWilliams (UCLA), M. R. E. Proctor (Cambridge), T. A. Yousef
(Cambridge) | Fluctuation dynamo and turbulent induction at low magnetic Prandtl
numbers | IoP latex, 27 pages, 25 figures, 3 tables. Accepted by New J. Physics | New J.Phys.9:300,2007 | 10.1088/1367-2630/9/8/300 | null | physics.flu-dyn astro-ph nlin.CD physics.plasm-ph | null | This paper is a detailed report on a programme of simulations used to settle
a long-standing issue in the dynamo theory and demonstrate that the fluctuation
dynamo exists in the limit of large magnetic Reynolds number Rm>>1 and small
magnetic Prandtl number Pm<<1. The dependence of the critical Rm_c vs. the
hydrodynamic Reynolds number Re is obtained for 1<Re<6700. In the limit Pm<<1,
Rm_c is ~3 times larger than for Pm>1. The stability curve Rm_c(Re) (and, it is
argued, the nature of the dynamo) is substantially different from the case of
the simulations and liquid-metal experiments with a mean flow. It is not as yet
possible to determine numerically whether the growth rate is ~Rm^{1/2} in the
limit Re>>Rm>>1, as should be the case if the dynamo is driven by the
inertial-range motions. The magnetic-energy spectrum in the low-Pm regime is
qualitatively different from the Pm>1 case and appears to develop a negative
spectral slope, although current resolutions are insufficient to determine its
asymptotic form. At 1<Rm<Rm_c, the magnetic fluctuations induced via the
tangling by turbulence of a weak mean field are investigated and the
possibility of a k^{-1} spectrum above the resistive scale is examined. At low
Rm<1, the induced fluctuations are well described by the quasistatic
approximation; the k^{-11/3} spectrum is confirmed for the first time in direct
numerical simulations.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 12:37:39 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Schekochihin",
"A. A.",
"",
"Imperial"
],
[
"Iskakov",
"A. B.",
"",
"UCLA"
],
[
"Cowley",
"S. C.",
"",
"UCLA"
],
[
"McWilliams",
"J. C.",
"",
"UCLA"
],
[
"Proctor",
"M. R. E.",
"",
"Cambridge"
],
[
"Yousef",
"T. A.",
"",
"Cambridge"
]
] |
0704.2003 | Fabrizio Lillo | Gabriella Vaglica, Fabrizio Lillo, Esteban Moro, Rosario N. Mantegna | Scaling laws of strategic behaviour and size heterogeneity in agent
dynamics | 6 pages, 3 figures | null | 10.1103/PhysRevE.77.036110 | null | q-fin.ST physics.soc-ph | null | The dynamics of many socioeconomic systems is determined by the decision
making process of agents. The decision process depends on agent's
characteristics, such as preferences, risk aversion, behavioral biases, etc..
In addition, in some systems the size of agents can be highly heterogeneous
leading to very different impacts of agents on the system dynamics. The large
size of some agents poses challenging problems to agents who want to control
their impact, either by forcing the system in a given direction or by hiding
their intentionality. Here we consider the financial market as a model system,
and we study empirically how agents strategically adjust the properties of
large orders in order to meet their preference and minimize their impact. We
quantify this strategic behavior by detecting scaling relations of allometric
nature between the variables characterizing the trading activity of different
institutions. We observe power law distributions in the investment time
horizon, in the number of transactions needed to execute a large order and in
the traded value exchanged by large institutions and we show that heterogeneity
of agents is a key ingredient for the emergence of some aggregate properties
characterizing this complex system.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 12:38:12 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Vaglica",
"Gabriella",
""
],
[
"Lillo",
"Fabrizio",
""
],
[
"Moro",
"Esteban",
""
],
[
"Mantegna",
"Rosario N.",
""
]
] |
0704.2004 | Oliver Melchert | O. Melchert and A. K. Hartmann | Fractal dimension of domain walls in two-dimensional Ising spin glasses | 8 pages, 8 figures, submitted to Phys. Rev. B; v2: shortened version | null | 10.1103/PhysRevB.76.174411 | null | cond-mat.dis-nn | null | We study domain walls in 2d Ising spin glasses in terms of a minimum-weight
path problem. Using this approach, large systems can be treated exactly. Our
focus is on the fractal dimension $d_f$ of domain walls, which describes via
$<\ell >\simL^{d_f}$ the growth of the average domain-wall length with %%
systems size $L\times L$. %% 20.07.07 OM %% Exploring systems up to L=320 we
yield $d_f=1.274(2)$ for the case of Gaussian disorder, i.e. a much higher
accuracy compared to previous studies. For the case of bimodal disorder, where
many equivalent domain walls exist due to the degeneracy of this model, we
obtain a true lower bound $d_f=1.095(2)$ and a (lower) estimate $d_f=1.395(3)$
as upper bound. Furthermore, we study the distributions of the domain-wall
lengths. Their scaling with system size can be described also only by the
exponent $d_f$, i.e. the distributions are monofractal. Finally, we investigate
the growth of the domain-wall width with system size (``roughness'') and find a
linear behavior.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:06:00 GMT"
},
{
"version": "v2",
"created": "Tue, 28 Aug 2007 12:45:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Melchert",
"O.",
""
],
[
"Hartmann",
"A. K.",
""
]
] |
0704.2005 | Peter Schenzel | Peter Schenzel | On the formal cohomology of local rings | 26 pages | null | null | null | math.AC math.AG | null | Let $\mathfrak a$ denote an ideal of a local ring $(R, \mathfrak m).$ Let $M$
be a finitely generated $R$-module. There is a systematic study of the formal
cohomology modules $\varprojlim \HH^i(M/\mathfrak a^nM), i \in \mathbb Z.$ We
analyze their $R$-module structure, the upper and lower vanishing and
non-vanishing in terms of intrinsic data of $M,$ and its functorial behavior.
These cohomology modules occur in relation to the formal completion of the
punctured spectrum $\Spec R \setminus V(\mathfrak m).$ As a new cohomological
data there is a description on the formal grade $\fgrade(\mathfrak a, M)$
defined as the minimal non-vanishing of the formal cohomology modules. There
are various exact sequences concerning the formal cohomology modules. Among
them a Mayer-Vietoris sequence for two ideals. It applies to new connectedness
results. There are also relations to local cohomological dimensions.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 12:42:10 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Schenzel",
"Peter",
""
]
] |
0704.2006 | M. C. Goorden | M. C. Goorden, M. Buttiker | Two-particle scattering matrix of two interacting mesoscopic conductors | 4 pages, 2 figures | Phys. Rev. Lett. 99, 146801 (2007) | 10.1103/PhysRevLett.99.146801 | null | cond-mat.mes-hall | null | We consider two quantum coherent conductors interacting weakly via long range
Coulomb forces. We describe the interaction in terms of two-particle collisions
described by a two-particle scattering matrix. As an example we determine the
transmission probability and correlations in a two-particle scattering
experiment and find that the results can be expressed in terms of the
density-of-states matrices of the non-interacting scatterers.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:29:23 GMT"
},
{
"version": "v2",
"created": "Fri, 5 Oct 2007 07:21:15 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Goorden",
"M. C.",
""
],
[
"Buttiker",
"M.",
""
]
] |
0704.2007 | Peter Schenzel | Peter Schenzel | On Lyubeznik's invariants and endomorphisms of local cohomology modules | Revised, extended and corrected version | null | null | null | math.AC math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Let $(R, \mathfrak m)$ denote an $n$-dimensional Gorenstein ring. For an
ideal $I \subset R$ of height $c$ we are interested in the endomorphism ring $B
= \Hom_R(H^c_I(R), H^c_I(R)).$ It turns out that $B$ is a commutative ring. In
the case of $(R,\mathfrak m)$ a regular local ring containing a field $B$ is a
Cohen-Macaulay ring. Its properties are related to the highest Lyubeznik number
$l = \dim_k \Ext_R^d(k,H^c_I(R)).$ In particular $R \simeq B$ if and only if $l
= 1.$ Moreover, we show that the natural homomorphism $\Ext_R^d(k, H^c_I(R))
\to k$ is non-zero.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 12:47:19 GMT"
},
{
"version": "v2",
"created": "Tue, 17 Apr 2007 08:41:59 GMT"
},
{
"version": "v3",
"created": "Thu, 7 May 2009 06:37:24 GMT"
}
] | 2009-05-07T00:00:00 | [
[
"Schenzel",
"Peter",
""
]
] |
0704.2008 | Valentin Rantsev-Kartinov A. | Valentin. A. Rantsev-Kartinov | Observations of Manifestations of Skeletal Structures of a Filamentary
Matter on the Sun | 10 pages, 5 figures, the materials of this paper was been partially
published in Proc. Conf.: 32-th EPS on Plasma Phys. and Contr. Fusion,
(2005); 4ICPDP, (2005); the 13th General Conference of the European Physical
Society, (2005) | AIP Conf.Proc.799:287-290,2005 | 10.1063/1.2134621 | null | astro-ph | null | The analysis of databases of photographic images of the Sun (obtained in
region of soft x-ray) by means of a method of multilevel dynamical contrasting,
has shown presence of skeletal structures of the Sun as outside (chromo-sphere
flashes and powerful coronal mass ejections) and on the Sun (structures in its
atmosphere, protuberances and of solar a stains). Moreover the structures which
radius of rotation is less than radius of a solar disk on breadth of their
observation have been revealed. On the basis of the obtained results of this
analysis, the author puts forward a hypothesis about an opportunity of
existence of some filamentary matter as inside, so outside of the Sun.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 12:59:49 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Rantsev-Kartinov",
"Valentin. A.",
""
]
] |
0704.2009 | Hsian-Hua Tseng | Yunfeng Jiang, Hsian-Hua Tseng | On Virasoro Constraints for Orbifold Gromov-Witten Theory | Typos and mistakes corrected | International Mathematics Research Notices, Vol. 2010, no. 4,
756--781 | null | null | math.AG math.SG | null | Virasoro constraints for orbifold Gromov-Witten theory are described. These
constraints are applied to the degree zreo, genus zero orbifold Gromov-Witten
potentials of the weighted projective stacks $\mathbb{P}(1,N)$,
$\mathbb{P}(1,1,N)$ and $\mathbb{P}(1,1,1,N)$ to obtain formulas of descendant
cyclic Hurwitz-Hodge integrals.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:03:51 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Apr 2007 12:35:40 GMT"
},
{
"version": "v3",
"created": "Mon, 21 May 2007 23:03:26 GMT"
}
] | 2010-04-09T00:00:00 | [
[
"Jiang",
"Yunfeng",
""
],
[
"Tseng",
"Hsian-Hua",
""
]
] |
0704.2010 | Juliana Bernardes | Juliana S Bernardes, Alberto Davila, Vitor Santos Costa, Gerson
Zaverucha | A study of structural properties on profiles HMMs | 6 pages, 7 figures | null | null | null | cs.AI | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Motivation: Profile hidden Markov Models (pHMMs) are a popular and very
useful tool in the detection of the remote homologue protein families.
Unfortunately, their performance is not always satisfactory when proteins are
in the 'twilight zone'. We present HMMER-STRUCT, a model construction algorithm
and tool that tries to improve pHMM performance by using structural information
while training pHMMs. As a first step, HMMER-STRUCT constructs a set of pHMMs.
Each pHMM is constructed by weighting each residue in an aligned protein
according to a specific structural property of the residue. Properties used
were primary, secondary and tertiary structures, accessibility and packing.
HMMER-STRUCT then prioritizes the results by voting. Results: We used the SCOP
database to perform our experiments. Throughout, we apply leave-one-family-out
cross-validation over protein superfamilies. First, we used the MAMMOTH-mult
structural aligner to align the training set proteins. Then, we performed two
sets of experiments. In a first experiment, we compared structure weighted
models against standard pHMMs and against each other. In a second experiment,
we compared the voting model against individual pHMMs. We compare method
performance through ROC curves and through Precision/Recall curves, and assess
significance through the paired two tailed t-test. Our results show significant
performance improvements of all structurally weighted models over default
HMMER, and a significant improvement in sensitivity of the combined models over
both the original model and the structurally weighted models.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:10:35 GMT"
},
{
"version": "v2",
"created": "Thu, 11 Dec 2008 18:47:26 GMT"
}
] | 2008-12-11T00:00:00 | [
[
"Bernardes",
"Juliana S",
""
],
[
"Davila",
"Alberto",
""
],
[
"Costa",
"Vitor Santos",
""
],
[
"Zaverucha",
"Gerson",
""
]
] |
0704.2011 | Alexander Semke | M.F.M. Lutz, C.L. Korpa and A. Semke | Self consistency in hadron physics | Invited talk presented by M.F.M.L. at YKIS 2006, 9 pages, 3 figures | Prog.Theor.Phys.Suppl.168:23-31,2007 | 10.1143/PTPS.168.23 | null | nucl-th | null | In this talk we discuss at hand of two examples the crucial role played by
self consistency in hadron physics. The first example concerns the quark-mass
dependence of the baryon octet and decuplet masses. It is shown that within a
self consistent one-loop approach based on the chiral Lagrangian the
'mysterious' quark-mass dependence of the $\Xi$ mass predicted by the MILC
collaboration may be recovered in terms of a discontinuous chiral
extrapolation. This is a consequence of self consistency imposed on the partial
summation, i.e. the masses used in the loop functions are identical to those
obtained from the baryon self energies. In the second example we discuss recent
studies on the properties of D mesons in cold nuclear matter as they are
predicted by coupled-channel dynamics. Here a self consistent many-body
approach reveals the close interlink of the properties of D meson and
open-charm baryon resonances in nuclear matter. The relevance of exotic baryon
resonances for the spectral distortion of the $D_s^\pm$ in nuclear matter is
pointed out.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:32:21 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lutz",
"M. F. M.",
""
],
[
"Korpa",
"C. L.",
""
],
[
"Semke",
"A.",
""
]
] |
0704.2012 | Goverdhan Khadekar S | Sanjeev Kumar and Ravendra Singh | Symmetry and Numerical Solutions for Systems of Non-linear Reaction
Diffusion Equations | 7 pages, 2 figures | null | null | null | math-ph math.MP math.NA | null | Many important applications are available for nonlinear reaction-diffusion
equation especially in the area of biology and engineering. Therefore a
mathematical model for Lie symmetry reduction of system of nonlinear
reaction-diffusion equation with respect to one-dimensional Algebra is carried
out in this work. Some classes of analytical and numerical solutions are
obtained and expressed using suitable graphs.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:33:46 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kumar",
"Sanjeev",
""
],
[
"Singh",
"Ravendra",
""
]
] |
0704.2013 | Marcelo Alves | M. Alves | The conical singularity method and the energy-momentum tensor near the
black hole horizon using the Kruskal coordinates | null | Mod.Phys.Lett.A22:3057-3063,2007 | 10.1142/S0217732307023651 | null | gr-qc hep-th | null | We apply the conical singularity method to the two dimensional version of the
Schwarzschild metric to obtain the Kruskal coordinates of the black hole in a
very simple and direct way. Then we make use of this metric in an approximated
version and calculate the expected value of energy-momentum tensor of a
massless quantum field near the horizon, resulting in regular expressions for
its components.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:34:49 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Alves",
"M.",
""
]
] |
0704.2014 | Leandro R\^ego | Joseph Y. Halpern, Leandro C. R\^ego | Extensive Games with Possibly Unaware Players | 45 pages, 3 figures, a preliminary version was presented at AAMAS06 | null | null | null | cs.GT cs.MA | null | Standard game theory assumes that the structure of the game is common
knowledge among players. We relax this assumption by considering extensive
games where agents may be unaware of the complete structure of the game. In
particular, they may not be aware of moves that they and other agents can make.
We show how such games can be represented; the key idea is to describe the game
from the point of view of every agent at every node of the game tree. We
provide a generalization of Nash equilibrium and show that every game with
awareness has a generalized Nash equilibrium. Finally, we extend these results
to games with awareness of unawareness, where a player i may be aware that a
player j can make moves that i is not aware of, and to subjective games, where
payers may have no common knowledge regarding the actual game and their beliefs
are incompatible with a common prior.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:58:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Halpern",
"Joseph Y.",
""
],
[
"Rêgo",
"Leandro C.",
""
]
] |
0704.2015 | Patrick Slane | Patrick Slane | Supernova Remnants and GLAST | 5 pages, to be published in "The Proceedings of the First
International GLAST Symposium", February 5-8, 2007, Stanford University, AIP,
Eds. S. Ritz, P. F. Michelson, and C. Meegan | AIP Conf.Proc.921:57-61,2007 | 10.1063/1.2757267 | null | astro-ph | null | It has long been speculated that supernova remnants represent a major source
of cosmic rays in the Galaxy. Observations over the past decade have
ceremoniously unveiled direct evidence of particle acceleration in SNRs to
energies approaching the knee of the cosmic ray spectrum. Nonthermal X-ray
emission from shell-type SNRs reveals multi-TeV electrons, and the dynamical
properties of several SNRs point to efficient acceleration of ions.
Observations of TeV gamma-ray emission have confirmed the presence of energetic
particles in several remnants as well, but there remains considerable debate as
to whether this emission originates with high energy electrons or ions. Equally
uncertain are the exact conditions that lead to efficient particle
acceleration.
Based on the catalog of EGRET sources, we know that there is a large
population of Galactic gamma-ray sources whose distribution is similar to that
of SNRs. With the increased resolution and sensitivity of GLAST, the gamma-ray
SNRs from this population will be identified. Their detailed emission
structure, along with their spectra, will provide the link between their
environments and their spectra in other wavebands to constrain emission models
and to potentially identify direct evidence of ion acceleration in SNRs. Here I
summarize recent observational and theoretical work in the area of cosmic ray
acceleration by SNRs, and discuss the contributions GLAST will bring to our
understanding of this problem.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:42:43 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Slane",
"Patrick",
""
]
] |
0704.2016 | Michael Creutz | Michael Creutz | The author replies | 3 pages. Rebuttal to arXiv:hep-lat/0603027. To appear in Physics
Letters B | Phys.Lett.B649:241-242,2007 | 10.1016/j.physletb.2007.04.017 | null | hep-lat | null | I respond to the Bernard et al. comment on my letter ``Chiral anomalies and
rooted staggered fermions.''
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:48:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Creutz",
"Michael",
""
]
] |
0704.2017 | Giacomo Bacci | G. Bacci, M. Luise, H.V. Poor | Large System Analysis of Game-Theoretic Power Control in UWB Wireless
Networks with Rake Receivers | To appear in the Proceedings of the 8th IEEE International Workshop
on Signal Processing Advances in Wireless Communications (SPAWC), Helsinki,
Finland, June 17-20, 2007 | null | 10.1109/SPAWC.2007.4401311 | null | cs.IT cs.GT math.IT | null | This paper studies the performance of partial-Rake (PRake) receivers in
impulse-radio ultrawideband wireless networks when an energy-efficient power
control scheme is adopted. Due to the large bandwidth of the system, the
multipath channel is assumed to be frequency-selective. By using noncooperative
game-theoretic models and large system analysis, explicit expressions are
derived in terms of network parameters to measure the effects of self- and
multiple-access interference at a receiving access point. Performance of the
PRake is compared in terms of achieved utilities and loss to that of the
all-Rake receiver.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:44:23 GMT"
}
] | 2016-11-17T00:00:00 | [
[
"Bacci",
"G.",
""
],
[
"Luise",
"M.",
""
],
[
"Poor",
"H. V.",
""
]
] |
0704.2018 | Alberto Lanconelli | Alberto Lanconelli | On a new version of the Ito's formula for the stochastic heat equation | 10 pages | null | null | null | math.PR | null | We derive an It\^o's-type formula for the one dimensional stochastic heat
equation driven by a space-time white noise. The proof is based on elementary
properties of the $\mathcal{S}$-transform and on the explicit representation of
the solution process. We also discuss the relationship with other versions of
this It\^o's-type formula existing in literature.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:53:34 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lanconelli",
"Alberto",
""
]
] |
0704.2019 | Michel Fliess | Michel Fliess (LIX, Inria Futurs) | Probabilit\'es et fluctuations quantiques (Probabilities and quantum
fluctuations) | null | Comptes rendus de l'acad\'emie des sciences, Math\'ematiques 344
(2007) 663-668 | null | null | quant-ph math-ph math.LO math.MP math.PR | null | This note is sketching a simple and natural mathematical construction for
explaining the probabilistic nature of quantum mechanics. It employs
nonstandard analysis and is based on Feynman's interpretation of the Heisenberg
uncertainty principle, i.e., of the quantum fluctuations, which was brought to
the forefront in some fractal approaches. It results, as in Nelson's stochastic
mechanics, in stochastic differential equations which are deduced from
infinitesimal random walks. An extended english abstract gives most of the
details.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 13:55:36 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Fliess",
"Michel",
"",
"LIX, Inria Futurs"
]
] |
0704.2020 | Peihong Gu | Pei-Hong Gu, Hong-Jian He, Utpal Sarkar | Neutrino Dark Energy and Baryon Asymmetry from Higgs Sector | 5 pages, 2 figures. Version accepted by PLB | Phys.Lett.B653:419-423,2007 | 10.1016/j.physletb.2007.07.014 | null | hep-ph | null | We propose a new model to explain the neutrino masses, the dark energy and
the baryon asymmetry altogether. In this model, neutrinos naturally acquire
small Majorana masses via type-II seesaw mechanism, while the
pseudo-Nambu-Goldstone bosons associated with the neutrino mass-generation
mechanism provide attractive candidates for dark energy. The baryon asymmetry
of the universe is produced from the Higgs triplets decay with CP-violation.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 14:01:16 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 08:52:04 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gu",
"Pei-Hong",
""
],
[
"He",
"Hong-Jian",
""
],
[
"Sarkar",
"Utpal",
""
]
] |
0704.2021 | Kenji Morita | Kenji Morita and Su Houng Lee | Mass Shift and Width Broadening of J/psi in hot gluonic plasma from QCD
Sum Rules | 4 pages, 5 figures, version to appear in Physical Review Letters | Phys.Rev.Lett.100:022301,2008 | 10.1103/PhysRevLett.100.022301 | null | nucl-th hep-ph | null | We investigate possible mass shift and width broadening of J/psi in hot
gluonic matter using QCD sum rule. Input values of gluon condensates at finite
temperature are extracted from lattice QCD data for the energy density and
pressure. Although stability of the moment ratio is achieved only up to T/Tc ~
1.05, the gluon condensates cause a decrease of the moment ratio, which results
in change of spectral properties. Using the Breit-Wigner form for the
phenomenological side, we find that mass shift of J/psi just above Tc can reach
maximally 200 MeV and width can broaden to dozens of MeV.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 14:01:49 GMT"
},
{
"version": "v2",
"created": "Wed, 21 Nov 2007 07:48:11 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Morita",
"Kenji",
""
],
[
"Lee",
"Su Houng",
""
]
] |
0704.2022 | C. Ryan Vinroot | Rod Gow and C. Ryan Vinroot | Extending real-valued characters of finite general linear and unitary
groups on elements related to regular unipotents | 27 pages | null | null | null | math.RT math.GR | null | When n is odd, consider the finite general linear and unitary groups of rank
n, extended by the inverse transpose automorphism. There are elements in the
extended groups which square to a regular unipotent element, and we evaluate
the values of irreducible characters of the extended groups on these elements.
Several intermediate results on real conjugacy classes and real-valued
characters of these groups are obtained along the way.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 14:18:18 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gow",
"Rod",
""
],
[
"Vinroot",
"C. Ryan",
""
]
] |
0704.2023 | Gurpur Prabhu | Chandru Iyer and G. M. Prabhu | Ordered addition of two Lorentz boosts through spatial and space-time
rotations | 9 pages, Content changed, Typo fixed, One reference added | null | null | null | physics.class-ph | null | The ordered addition of two Lorentz boosts is normally shown to result in a
boost by utilizing concepts from group theory and non-Euclidian geometry. We
present a method for achieving this addition by performing a sequence of
spatial rotations and uni-dimensional Lorentz transformations. The method is
first developed for two-dimensional space and it is then extended to
three-dimensional space by utilizing the commutative property of the rotation
of the y-z plane and a boost along the x-axis. The method employs only matrix
multiplication and certain invariant quantities that are natural consequences
of spatial rotations and Lorentz transformations. The combining of two boosts
in different directions into a single boost cannot be expected a priori because
we show that the converse of this statement is not true. That is, two rotations
interspersed with a boost cannot always be reduced to a single rotation
preceded and followed by boosts.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 14:20:12 GMT"
},
{
"version": "v2",
"created": "Thu, 3 May 2007 16:18:14 GMT"
},
{
"version": "v3",
"created": "Tue, 8 May 2007 14:35:24 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Iyer",
"Chandru",
""
],
[
"Prabhu",
"G. M.",
""
]
] |
0704.2024 | Francois Ducastelle | Hakim Amara (LPS, PCPM, CERMIN), Christophe Bichara (CRMCN),
Fran\c{c}ois Ducastelle (LEM) | A Tight-Binding Grand Canonical Monte Carlo Study of the Catalytic
Growth of Carbon Nanotubes | null | null | null | null | cond-mat.mtrl-sci | null | The nucleation of carbon nanotubes on small nickel clusters is studied using
a tight binding model coupled to grand canonical Monte Carlo simulations. This
technique closely follows the conditions of the synthesis of carbon nanotubes
by chemical vapor deposition. The possible formation of a carbon cap on the
catalyst particle is studied as a function of the carbon chemical potential,
for particles of different size, either crystalline or disordered. We show that
these parameters strongly influence the structure of the cap/particle interface
which in turn will have a strong effect on the control of the structure of the
nanotube. In particular, we discuss the presence of carbon on surface or in
subsurface layers.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 14:25:05 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Amara",
"Hakim",
"",
"LPS, PCPM, CERMIN"
],
[
"Bichara",
"Christophe",
"",
"CRMCN"
],
[
"Ducastelle",
"François",
"",
"LEM"
]
] |
0704.2025 | Peng Gao | Peng Gao | A Note on Sums of Powers | 4 pages | null | null | null | math.CA | null | We improve a result of Bennett concerning certain sequences involving sums of
powers of positive integers.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 14:33:27 GMT"
},
{
"version": "v2",
"created": "Tue, 17 Apr 2007 18:19:33 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Gao",
"Peng",
""
]
] |
0704.2026 | Sandrine Bec | Christelle Guerret-Piecourt (PCP, IFoS), Sandrine Bec (LTDS),
Fr\'ed\'eric S\'egault (LTDS), Denyse Juv\'e (IFoS), Daniel Tr\'eheux (IFoS),
Andr\'e Tonck (LTDS) | Adhesion forces due to nano-triboelectrification between similar
materials | null | The European Physical Journal : Applied Physics 28 (2004) 65-72 | 10.1051/epjap:2004152 | null | physics.class-ph | null | Contact electrification and triboelectrification are well-known in the case
of dissimilar materials, however the case of charge exchange during friction
between nominally identical insulating materials is less documented. We
experimentally investigated the triboelectrification between two smooth
monocrystalline α-Al 2O 3 (sapphire) antagonists by surface force
measurements with a Surface Force Apparatus (SFA). The force between a sphere
and a plane, both in sapphire, was measured as a function of the sphere-plane
distance D, before and after nano-friction tests, under dry argon atmosphere.
Respective contributions of van der Waals, water meniscus and electrostatic
forces were determined. The estimated Hamaker constant was in good agreement
with the Lifshitz theory, and the dominant meniscus attraction at low
separation could be overcome with small radius sphere. We demonstrated that
electrostatic forces were generated by the nano-friction test and we quantified
the adhesion that results from this contact-electrification. In the first stage
of the unloading process, the short range electrostatic force was found to vary
both with time and distance D. Experimental results were correlated with
surface densities of mobile charges on the two surfaces, and the
time-dependence was related to classical surface transport phenomena on alumina
surfaces.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 14:37:01 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Guerret-Piecourt",
"Christelle",
"",
"PCP, IFoS"
],
[
"Bec",
"Sandrine",
"",
"LTDS"
],
[
"Ségault",
"Frédéric",
"",
"LTDS"
],
[
"Juvé",
"Denyse",
"",
"IFoS"
],
[
"Tréheux",
"Daniel",
"",
"IFoS"
],
[
"Tonck",
"André",
"",
"LTDS"
]
] |
0704.2027 | Christian Roos | M. Riebe, M. Chwalla, J. Benhelm, H. Haeffner, W. Haensel, C. F. Roos,
and R. Blatt | Quantum teleportation with atoms: quantum process tomography | null | New J. Phys. 9, 211 (2007) | 10.1088/1367-2630/9/7/211 | null | quant-ph | null | The performance of a quantum teleportation algorithm implemented on an ion
trap quantum computer is investigated. First the algorithm is analyzed in terms
of the teleportation fidelity of six input states evenly distributed over the
Bloch sphere. Furthermore, a quantum process tomography of the teleportation
algorithm is carried out which provides almost complete knowledge about the
algorithm.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 14:44:43 GMT"
}
] | 2011-11-09T00:00:00 | [
[
"Riebe",
"M.",
""
],
[
"Chwalla",
"M.",
""
],
[
"Benhelm",
"J.",
""
],
[
"Haeffner",
"H.",
""
],
[
"Haensel",
"W.",
""
],
[
"Roos",
"C. F.",
""
],
[
"Blatt",
"R.",
""
]
] |
0704.2028 | Manuel J. Schmidt | M.J. Schmidt, K. Pappert, C. Gould, G. Schmidt, R. Oppermann, L.W.
Molenkamp | Bound hole states in a ferromagnetic (Ga,Mn)As environment | 9 pages, 10 figures | PHYSICAL REVIEW B Volume: 76 Issue: 12 Article Number: 125206
Published: 2007 | 10.1103/PhysRevB.76.035204 | null | cond-mat.mtrl-sci cond-mat.dis-nn | null | A numerical technique is developed to solve the Luttinger-Kohn equation for
impurity states directly in k-space and is applied to calculate bound hole wave
functions in a ferromagnetic (Ga,Mn)As host. The rich properties of the band
structure of an arbitrarily strained, ferromagnetic zinc-blende semiconductor
yields various features which have direct impact on the detailed shape of a
valence band hole bound to an active impurity. The role of strain is discussed
on the basis of explicit calculations of bound hole states.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 14:45:22 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Schmidt",
"M. J.",
""
],
[
"Pappert",
"K.",
""
],
[
"Gould",
"C.",
""
],
[
"Schmidt",
"G.",
""
],
[
"Oppermann",
"R.",
""
],
[
"Molenkamp",
"L. W.",
""
]
] |
0704.2029 | Bertfried Fauser | Bertfried Fauser, Peter D. Jarvis, and Ronald C. King | The Hopf Algebra Structure of the Character Rings of Classical Groups | 38 pages, uses pstricks; new version is a major update, new title,
new material on rational characters | null | null | MPI-MIS 36/2007 | math.RT math.CO math.RA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The character ring \CGL of covariant irreducible tensor representations of
the general linear group admits a Hopf algebra structure isomorphic to the Hopf
algebra \Sym$ of symmetric functions. Here we study the character rings \CO and
\CSp of the orthogonal and symplectic subgroups of the general linear group
within the same framework of symmetric functions. We show that \CO and \CSp
also admit natural Hopf algebra structures that are isomorphic to that of \CGL,
and hence to \Sym. The isomorphisms are determined explicitly, along with the
specification of standard bases for \CO and \CSp analogous to those used for
\Sym. A major structural change arising from the adoption of these bases is the
introduction of new orthogonal and symplectic Schur-Hall scalar products.
Significantly, the adjoint with respect to multiplication no longer coincides,
as it does in the \CGL case, with a Foulkes derivative or skew operation. The
adjoint and Foulkes derivative now require separate definitions, and their
properties are explored here in the orthogonal and symplectic cases. Moreover,
the Hopf algebras \CO and \CSp are not self-dual. The dual Hopf algebras \CO^*
and \CSp^* are identified. Finally, the Hopf algebra of the universal rational
character ring \CGLrat of mixed irreducible tensor representations of the
general linear group is introduced and its structure maps identified.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:22:05 GMT"
},
{
"version": "v2",
"created": "Thu, 26 Jul 2012 15:17:23 GMT"
}
] | 2012-07-27T00:00:00 | [
[
"Fauser",
"Bertfried",
""
],
[
"Jarvis",
"Peter D.",
""
],
[
"King",
"Ronald C.",
""
]
] |
0704.2030 | Nikolai Durov | Nikolai Durov (Max Planck Institute for Mathematics, St.Petersburg
State University) | New Approach to Arakelov Geometry | 568 pages, with hyperlinks | null | null | null | math.AG math.NT | null | This work is dedicated to a new completely algebraic approach to Arakelov
geometry, which doesn't require the variety under consideration to be
generically smooth or projective. In order to construct such an approach we
develop a theory of generalized rings and schemes, which include classical
rings and schemes together with "exotic" objects such as F_1 ("field with one
element"), Z_\infty ("real integers"), T (tropical numbers) etc., thus
providing a systematic way of studying such objects.
This theory of generalized rings and schemes is developed up to construction
of algebraic K-theory, intersection theory and Chern classes. Then existence of
Arakelov models of algebraic varieties over Q is shown, and our general results
are applied to such models.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 17:38:22 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Durov",
"Nikolai",
"",
"Max Planck Institute for Mathematics, St.Petersburg\n State University"
]
] |
0704.2031 | Graziano Guerra Dr | Rinaldo M. Colombo and Graziano Guerra | Hyperbolic Balance Laws with a Non Local Source | 26 pages | Comm. Partial Differential Equations., 32(12):1917-1939, 2007. | 10.1080/03605300701318849 | null | math.AP | null | This paper is devoted to hyperbolic systems of balance laws with non local
source terms. The existence, uniqueness and Lipschitz dependence proved here
comprise previous results in the literature and can be applied to physical
models, such as Euler system for a radiating gas and Rosenau regularization of
the Chapman-Enskog expansion.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 15:02:45 GMT"
}
] | 2007-12-13T00:00:00 | [
[
"Colombo",
"Rinaldo M.",
""
],
[
"Guerra",
"Graziano",
""
]
] |
0704.2032 | Gustavo A. Lanfranchi | Gustavo A. Lanfranchi (1), Francesca Matteucci (2,3), ((1)Nucleo de
Astrofisica Teorica-UNICSUL, Brazil (2) Dipartimento di Astronomia-Universita
di Trieste, Italy, (3) I.N.A.F. Osservatorio Astronomico di Trieste, Italy) | Effects of the galactic winds on the stellar metallicity distribution of
dwarf spheroidal galaxies | 11 pages, 7 figures, accepted for publication in Asttronomy &
Astrophysics | null | 10.1051/0004-6361:20066576 | null | astro-ph | null | To study the effects of galactic winds on the stellar metallicity
distributions and on the evolution of Draco and Ursa Minor dwarf spheroidal
galaxies, we compared the predictions of several chemical evolution models,
adopting different prescriptions for the galactic winds, with the
photometrically-derived stellar metallicity distributions of both galaxies. The
chemical evolution models for Draco and Ursa Minor, which are able to reproduce
several observational features of these two galaxies, such as the several
abundance ratios, take up-to-date nucleosynthesis into account for
intermediate-mass stars and supernovae of both types, as well as the effect of
these objects on the energetics of the systems. For both galaxies, the model
that best fits the data contains an intense continuous galactic wind, occurring
at a rate proportional to the star formation rate. Models with a wind rate
assumed to be proportional only to the supernova rate also reproduce the
observed SMD, but do not match the gas mass, whereas the models with no
galactic winds fail to reproduce the observed SMDs. In the case of Ursa Minor,
the same model as in previous works reproduces the observed distribution very
well with no need to modify the main parameters of the model. The model for
Draco, on the other hand, is slightly modified. The observed SMD requires a
model with a lower supernova type Ia thermalization efficiency ($\eta_{SNeIa}$
= 0.5 instead of $\eta_{SNeIa}$ = 1.0) in order to delay the galactic wind,
whereas all the other parameters are kept the same. The model results, compared
to observations, strongly suggest that intense and continuous galactic winds
play a very important role in the evolution of local dSphs.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 15:07:12 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lanfranchi",
"Gustavo A.",
""
],
[
"Matteucci",
"Francesca",
""
]
] |
0704.2033 | Anwar Shiekh Dr. | A.Y. Shiekh | The Quantum Interference Computer: an experimental proposal | 6 pages, 1 figure | Int. Jour. of Theo. Phys., 47, 2176, 2008 | 10.1007/s10773-008-9664-7 | null | quant-ph | null | An experiment is proposed to test the interference aspect of the Quantum
Interference Computer approach
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 15:34:25 GMT"
},
{
"version": "v2",
"created": "Sat, 21 Jul 2007 21:00:24 GMT"
},
{
"version": "v3",
"created": "Tue, 2 Oct 2007 19:57:44 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Shiekh",
"A. Y.",
""
]
] |
0704.2034 | Tom Coates | Tom Coates, Alessio Corti, Hiroshi Iritani, Hsian-Hua Tseng | The Crepant Resolution Conjecture for Type A Surface Singularities | 19 pages. v2: references updated; corrected our description of the
work of Davesh Maulik. v3: please note that this preprint has been superseded
by arXiv:math/0702234v3. The material here, with various typos corrected,
appears as Appendix A there | null | null | null | math.AG math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Let X be an orbifold with crepant resolution Y. The Crepant Resolution
Conjectures of Ruan and Bryan-Graber assert, roughly speaking, that the quantum
cohomology of X becomes isomorphic to the quantum cohomology of Y after
analytic continuation in certain parameters followed by the specialization of
some of these parameters to roots of unity. We prove these conjectures in the
case where X is a surface singularity of type A. The key ingredient is mirror
symmetry for toric orbifolds.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 18:56:34 GMT"
},
{
"version": "v2",
"created": "Mon, 22 Oct 2007 07:47:57 GMT"
},
{
"version": "v3",
"created": "Thu, 10 Jul 2008 06:46:10 GMT"
}
] | 2008-07-10T00:00:00 | [
[
"Coates",
"Tom",
""
],
[
"Corti",
"Alessio",
""
],
[
"Iritani",
"Hiroshi",
""
],
[
"Tseng",
"Hsian-Hua",
""
]
] |
0704.2035 | Petr Marek | Petr Marek, Jinhyoung Lee, M. S. Kim | Vacuum as a less hostile environment to entanglement | Replaced by the published version | Phys. Rev. A 77, 032302 (2008) | 10.1103/PhysRevA.77.032302 | null | quant-ph | null | We derive sufficient conditions for infinite-dimensional systems whose
entanglement is not completely lost in a finite time during its decoherence by
a passive interaction with local vacuum environments. The sufficient conditions
allow us to clarify a class of bipartite entangled states which preserve their
entanglement or, in other words, are tolerant against decoherence in a vacuum.
We also discuss such a class for entangled qubits.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 15:36:40 GMT"
},
{
"version": "v2",
"created": "Wed, 2 May 2007 16:10:08 GMT"
},
{
"version": "v3",
"created": "Wed, 5 Mar 2008 10:53:04 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Marek",
"Petr",
""
],
[
"Lee",
"Jinhyoung",
""
],
[
"Kim",
"M. S.",
""
]
] |
0704.2036 | Karen Johnston | Karen Johnston and Risto M. Nieminen | Polymer adhesion: first-principles calculations of the adsorption of
organic molecules onto Si surfaces | 8 pages, 13 figures | null | 10.1103/PhysRevB.76.085402 | null | cond-mat.mtrl-sci | null | The structures and energetics of organic molecules adsorbed onto clean and
H-passivated Si(001)-(2$\times$1) surfaces have been calculated using density
functional theory. For benzene adsorbed on the clean Si surface the
tight-bridge structure was found to be stable and the butterfly structure
metastable. Both carbonic acid H$_2$CO$_3$ and propane C$_3$H$_8$ dissociate on
contact with the surface. Passivation of the Si surface with H-atoms has a
dramatic effect on the surface properties. The passivated surface is very inert
and the binding energy of all the molecules is very weak.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 15:38:53 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Johnston",
"Karen",
""
],
[
"Nieminen",
"Risto M.",
""
]
] |
0704.2037 | Tom Girard | T. Morlata, M. Felizardo, F. Giuliani, TA Girard, G. Waysand, R.F.
Payne, H.S. Miley, A.R. Ramos, J.G. Marques, R.C. Martins, D. Limagne | A CF3I-based SDD Prototype for Spin-independent Dark Matter Searches | revised and updated; accepted Astrop. Phys | null | null | null | astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The application of Superheated Droplet Detectors (SDDs) to dark matter
searches has so far been confined to the light nuclei refrigerants C2ClF5 and
C4F10 (SIMPLE and PICASSO, respectively), with a principle sensitivity to
spin-dependent interactions. Given the competitive results of these devices, as
a result of their intrinsic insensitivity to backgrounds, we have developed a
prototype trifluoroiodomethane (CF3I)-loaded SDD with increased sensitivity to
spin-independent interactions as well. A low (0.102 kgd) exposure test
operation of two high concentration, 1 liter devices is described, and the
results compared with leading experiments in both spin-dependent and
-independent sectors. Although competitive in both sectors when the difference
in exposures is accounted for, a problem with fracturing of the detector gel
must be addressed before significantly larger exposures can be envisioned.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 17:55:35 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Aug 2008 13:39:50 GMT"
}
] | 2008-08-26T00:00:00 | [
[
"Morlata",
"T.",
""
],
[
"Felizardo",
"M.",
""
],
[
"Giuliani",
"F.",
""
],
[
"Girard",
"TA",
""
],
[
"Waysand",
"G.",
""
],
[
"Payne",
"R. F.",
""
],
[
"Miley",
"H. S.",
""
],
[
"Ramos",
"A. R.",
""
],
[
"Marques",
"J. G.",
""
],
[
"Martins",
"R. C.",
""
],
[
"Limagne",
"D.",
""
]
] |
0704.2038 | Marc Holman | M. Holman | Non-Viability of a Counter-Argument to Bell's Theorem | 2 pages, no figures; v2, two minor semantical changes - in order to
resolve some apparent confusion in the mind of some reader - conclusion
remains unaffected | null | null | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is demonstrated that a recently suggested model for the EPR-Bohm spin
experiment, based on Clifford algebra valued local variables and observables,
runs into very serious difficulties and can therefore not be taken as
constituting a viable counter-example to Bell's theorem.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 19:45:29 GMT"
},
{
"version": "v2",
"created": "Fri, 25 Sep 2009 17:47:31 GMT"
}
] | 2009-09-25T00:00:00 | [
[
"Holman",
"M.",
""
]
] |
0704.2039 | Peter Van | P. V\'an and T. S. Bir\'o | Relativistic hydrodynamics - causality and stability | 14 pages, 2 figures, completely revised | Eur.Phys.J.ST155:201-212,2008 | 10.1140/epjst/e2008-00602-6 | null | nucl-th | null | Causality and stability in relativistic dissipative hydrodynamics are
important conceptual issues. We argue that causality is not restricted to
hyperbolic set of differential equations. E.g. heat conduction equation can be
causal considering the physical validity of the theory. Furthermore we propose
a new concept of relativistic internal energy that clearly separates the
dissipative and non-dissipative effects. We prove that with this choice we
remove all known instabilities of the linear response approximation of viscous
and heat conducting relativistic fluids. In this paper the Eckart choice of the
velocity field is applied.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 15:53:43 GMT"
},
{
"version": "v2",
"created": "Sun, 11 Nov 2007 17:45:34 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ván",
"P.",
""
],
[
"Biró",
"T. S.",
""
]
] |
0704.2040 | Wanke Yin | Xiaojun Huang, Wanke Yin | A Bishop surface with a vanishing Bishop invariant | null | null | null | null | math.CV math.DG | null | We derive a complete set of invariants for a formal Bishop surface near a
point of complex tangent with a vanishing Bishop invariant under the action of
formal transformations. We prove that the modular space of Bishop surfaces with
a vanishing Bishop invariant and with a fixed Moser invariant $s<\infty$ is of
infinite dimension. We also prove that the equivalence class of the germ of a
generic real analytic Bishop surface near a complex tangent with a vanishing
Bishop invariant can not be determined by a finite part of the Taylor expansion
of its defining equation. This answers, in the negative, a problem raised by J.
Moser in 1985 after his joint work with Webster in 1983 and his own work in
1985.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 15:58:40 GMT"
},
{
"version": "v2",
"created": "Tue, 17 Apr 2007 06:35:42 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Huang",
"Xiaojun",
""
],
[
"Yin",
"Wanke",
""
]
] |
0704.2041 | Walter D. Neumann | Lev Birbrair, Alexandre Fernandes, Walter D. Neumann | Bi-Lipschitz geometry of weighted homogeneous surface singularities | 5 pages. Added result that nonhomogeneous cyclic quotients are not
conical | Math. Ann. 342 (2008), 139--144 | 10.1007/s00208-008-0225-4 | null | math.AG math.GT math.MG | null | We show that a weighted homogeneous complex surface singularity is metrically
conical (i.e., bi-Lipschitz equivalent to a metric cone) only if its two lowest
weights are equal. We also give an example of a pair of weighted homogeneous
complex surface singularities that are topologically equivalent but not
bi-Lipschitz equivalent.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:03:09 GMT"
},
{
"version": "v2",
"created": "Tue, 14 Aug 2007 17:26:18 GMT"
},
{
"version": "v3",
"created": "Fri, 7 Dec 2007 14:41:11 GMT"
}
] | 2008-09-04T00:00:00 | [
[
"Birbrair",
"Lev",
""
],
[
"Fernandes",
"Alexandre",
""
],
[
"Neumann",
"Walter D.",
""
]
] |
0704.2042 | Tim Clunan | Tim Clunan | The No-Boundary Probability for the Universe starting at the top of the
hill | 8 pages, 3 figures | null | null | DAMTP-2007-35 | hep-th | null | We use the Hartle-Hawking No-Boundary Proposal to make a comparison between
the probabilities of the universe starting near, and at, the top of a hill in
the effective potential. In the context of top-down cosmology, our calculation
finds that the universe doesn't start at the top.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:05:35 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Clunan",
"Tim",
""
]
] |
0704.2043 | Oded Hod | Oded Hod, Veronica Barone, Juan E. Peralta, and Gustavo E. Scuseria | Enhanced Half-Metallicity in Edge-Oxidized Zigzag Graphene Nanoribbons | 5 pages,5 figures, 1 table | Nano Letters 7, 2295-2299 (2007) | 10.1021/nl0708922 | null | cond-mat.mtrl-sci cond-mat.other | null | We present a novel comprehensive first-principles theoretical study of the
electronic properties and relative stabilities of edge-oxidized zigzag graphene
nanoribbons. The oxidation schemes considered include hydroxyl, carboxyl,
ether, and ketone groups. Using screened exchange density functional theory, we
show that these oxidized ribbons are more stable than hydrogen-terminated
nanoribbons except for the case of the etheric groups. The stable oxidized
configurations maintain a spin-polarized ground state with antiferromagnetic
ordering localized at the edges, similar to the fully hydrogenated
counterparts. More important, edge oxidation is found to lower the onset
electric field required to induce half-metallic behavior and extend the overall
field range at which the systems remain half-metallic. Once the half-metallic
state is reached, further increase of the external electric field intensity
produces a rapid decrease in the spin magnetization up to a point where the
magnetization is quenched completely. Finally, we find that oxygen containing
edge groups have a minor effect on the energy difference between the
antiferromagnetic ground state and the above-lying ferromagnetic state.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:15:24 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Hod",
"Oded",
""
],
[
"Barone",
"Veronica",
""
],
[
"Peralta",
"Juan E.",
""
],
[
"Scuseria",
"Gustavo E.",
""
]
] |
0704.2044 | Edouard Brezin | E. Brezin and S. Hikami | Vertices from replica in a random matrix theory | null | null | 10.1088/1751-8113/40/45/005 | null | math-ph hep-th math.MP | null | Kontsevitch's work on Airy matrix integrals has led to explicit results for
the intersection numbers of the moduli space of curves. In a subsequent work
Okounkov rederived these results from the edge behavior of a Gaussian matrix
integral. In our work we consider the correlation functions of vertices in a
Gaussian random matrix theory, with an external matrix source, in a scaling
limit in which the powers of the matrices and their sizes go to infinity
simultaneously in a specified scale. We show that the replica method applied to
characteristic polynomials of the random matrices, together with a duality
exchanging N and the number of points, allows one to recover Kontsevich's
results on the intersection numbers, through a simple saddle-point analysis.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:17:41 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Brezin",
"E.",
""
],
[
"Hikami",
"S.",
""
]
] |
0704.2045 | Chris Quigg | Chris Quigg | Higgs Bosons, Electroweak Symmetry Breaking, and the Physics of the
Large Hadron Collider | 15 pages, 6 figures, uses Contemporary Physics macros (included) | Contemp.Phys.48:1-11,2007 | 10.1080/00107510701292187 | FERMILAB-PUB-07/002-T | hep-ph hep-ex | null | The Large Hadron Collider, a 7 + 7 TeV proton-proton collider under
construction at CERN (the European Laboratory for Particle Physics in Geneva),
will take experiments squarely into a new energy domain where mysteries of the
electroweak interaction will be unveiled. What marks the 1-TeV scale as an
important target? Why is understanding how the electroweak symmetry is hidden
important to our conception of the world around us? What expectations do we
have for the agent that hides the electroweak symmetry? Why do particle
physicists anticipate a great harvest of discoveries within reach of the LHC?
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:26:07 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Quigg",
"Chris",
""
]
] |
0704.2046 | Anne Schilling | Anne Schilling | Combinatorial structure of Kirillov-Reshetikhin crystals of type D_n(1),
B_n(1), A_{2n-1}(2) | 23 pages; version 3: references added, role of [27] clarified | J.Algebra319:2938-2962,2008 | 10.1016/j.jalgebra.2007.10.020 | null | math.QA math.CO | null | We provide the explicit combinatorial structure of the Kirillov-Reshetikhin
crystals B^{r,s} of type D_n(1), B_n(1), and A_{2n-1}(2). This is achieved by
constructing the crystal analogue sigma of the automorphism of the D_n(1)
(resp. B_n(1) or A_{2n-1}(2)) Dynkin diagram that interchanges the 0 and 1
node. The involution sigma is defined in terms of new plus-minus diagrams that
govern the D_n to D_{n-1} (resp. B_n to B_{n-1}, or C_n to C_{n-1}) branching.
It is also shown that the crystal B^{r,s} is perfect. These crystals have been
implemented in MuPAD-Combinat; the implementation is discussed in terms of many
examples.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:26:31 GMT"
},
{
"version": "v2",
"created": "Thu, 3 May 2007 06:46:14 GMT"
},
{
"version": "v3",
"created": "Wed, 24 Oct 2007 22:44:16 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Schilling",
"Anne",
""
]
] |
0704.2047 | Oleg Smirnov | A.Derbin, A.Ianni, and O.Smirnov | Comment on the statistical analysis in "A new experimental limit for the
stability of the electron" by H.V. Klapdor-Kleingrothaus, I.V. Krivosheina
and I.V. Titkova | 4 pages, 2 tables | null | null | null | hep-ex | null | We point out the evident errors in statistical analysis of the data,
performed by Klapdor-Kleingrothaus et al in recently published paper to
establish a limit on the stability of electron with respect to the decay into
$\nu+\gamma$. We performed the reestimation of the sensitivity of the
experimental setups to the 256 keV gamma emitted in the hypothetical electron
decay, and show that in [1] the limits on the electron stability and charge
nonconservation parameter $\epsilon_{e\nu\gamma}^{2}$ are overestimated by at
least a factor of 5. We have revealed evident errors in the statistical
analysis, performed by Klapdor-Kleingrothaus et al in a recently published
paper [1] to establish a limit on the stability of electron with respect to the
decay into $\nu+\gamma$. The performed reestimation of the sensitivity of the
experimental setups to the 256 keV gamma emitted in the hypothetical electron
decay, has shown that the limits on the electron stability and charge
nonconservation parameter $\epsilon_{e\nu\gamma}^{2}$ presented in [1], have
been overestimated by at least a factor of 5.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:32:44 GMT"
},
{
"version": "v2",
"created": "Tue, 1 May 2007 13:12:23 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Derbin",
"A.",
""
],
[
"Ianni",
"A.",
""
],
[
"Smirnov",
"O.",
""
]
] |
0704.2048 | Toufik Mansour Dr. | W.M.B. Dukes, Mark F. Flanagan, Toufik Mansour, V. Vajnovszki | Combinatorial Gray codes for classes of pattern avoiding permutations | 18 pages | null | null | null | math.CO | null | The past decade has seen a flurry of research into pattern avoiding
permutations but little of it is concerned with their exhaustive generation.
Many applications call for exhaustive generation of permutations subject to
various constraints or imposing a particular generating order. In this paper we
present generating algorithms and combinatorial Gray codes for several families
of pattern avoiding permutations. Among the families under consideration are
those counted by Catalan, Schr\"oder, Pell, even index Fibonacci numbers and
the central binomial coefficients. Consequently, this provides Gray codes for
$\s_n(\tau)$ for all $\tau\in \s_3$ and the obtained Gray codes have distances
4 and 5.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:35:17 GMT"
},
{
"version": "v2",
"created": "Wed, 9 Jan 2008 17:32:39 GMT"
}
] | 2008-01-09T00:00:00 | [
[
"Dukes",
"W. M. B.",
""
],
[
"Flanagan",
"Mark F.",
""
],
[
"Mansour",
"Toufik",
""
],
[
"Vajnovszki",
"V.",
""
]
] |
0704.2049 | Mattias Marklund | M. Marklund, B. Eliasson, P. K. Shukla | Magnetosonic solitons in a Fermionic quantum plasma | 8 pages, 3 figures, version to appear in Physical Review E | Phys. Rev. E 76, 067401 (2007) | 10.1103/PhysRevE.76.067401 | null | physics.plasm-ph | null | Starting from the governing equations for a quantum magnetoplasma including
the quantum Bohm potential and electron spin-1/2 effects, we show that the
system of quantum magnetohydrodynamic (QMHD) equations admit rarefactive
solitons due to the balance between nonlinearities and quantum
diffraction/tunneling effects. It is found that the electron spin-1/2 effect
introduces a pressure-like term with negative sign in the QMHD equations, which
modifies the shape of the solitary magnetosonic waves and makes them wider and
shallower. Numerical simulations of the time-dependent system shows the
development of rarefactive QMHD solitary waves that are modified by the spin
effects.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:36:20 GMT"
},
{
"version": "v2",
"created": "Wed, 14 Nov 2007 19:22:33 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Marklund",
"M.",
""
],
[
"Eliasson",
"B.",
""
],
[
"Shukla",
"P. K.",
""
]
] |
0704.2050 | Dorin Ervin Dutkay | Dorin Ervin Dutkay and Palle E.T. Jorgensen | A duality approach to representations of Baumslag-Solitar groups | v2, technical problem around Corollary 7.5 was corected | A duality approach to representations of Baumslag-Solitar groups.
Group representations, ergodic theory, and mathematical physics: a tribute to
George W. Mackey, 99--127, Contemp. Math., 449, Amer. Math. Soc., Providence,
RI, 2008. | null | null | math.OA math.FA | null | We give an operator theoretic approach to the constructions of
multiresolutions as they are used in a number of basis constructions with
wavelets, and in Hilbert spaces on fractals. Our approach starts with the
following version of the classical Baumslag-Solitar relations $u t = t^2 u$
where $t$ is a unitary operator in a Hilbert space $\mathcal H$ and $u$ is an
isometry in $\mathcal H$. There are isometric dilations of this system into a
bigger Hilbert space, relevant for wavelets. For a variety of carefully
selected dilations, the ``bigger'' Hilbert space may be $L^2(\br)$, and the
dilated operators may be the unitary operators which define a dyadic wavelet
multiresolutions of $L^2(\br)$ with the subspace $\mathcal H$ serving as the
corresponding resolution subspace. That is, the initialized resolution which is
generated by the wavelet scaling function(s). In the dilated Hilbert space, the
Baumslag-Solitar relations then take the more familiar form $u t u^{-1} = t^2$.
We offer an operator theoretic framework including the standard construction;
and we show how the representations of certain discrete semidirect group
products serve to classify the possibilities. For this we analyze and compare
several types of unitary representations of these semidirect products: the
induced representations in Mackey's theory, the wavelet representations on
$L^2(\br)$, the irreducible representation on the dual, the finite dimensional
representations, and the the regular representation.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:38:47 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Apr 2007 23:31:59 GMT"
},
{
"version": "v3",
"created": "Mon, 25 Jun 2007 19:32:30 GMT"
}
] | 2008-12-29T00:00:00 | [
[
"Dutkay",
"Dorin Ervin",
""
],
[
"Jorgensen",
"Palle E. T.",
""
]
] |
0704.2051 | Derek Moss | D. Moss, N. Seymour, I. M. McHardy, T. Dwelly, M. J. Page, N. S.
Loaring | A 610 MHz Survey of the 1H XMM-Newton/Chandra Survey Field | 13 pages, 8 figures, 2 tables. Accepted for publication in MNRAS | null | null | null | astro-ph | null | We present the results of a deep 610 MHz survey of the 1^H XMM/Chandra survey
area with the GMRT. The resulting maps have a resolution of ~7 arcsec and an
rms noise limit of 60 microJy. To a 5 sigma detection limit of 300 microJy we
detect 223 sources within a survey area of diameter 64 arcmin. We compute the
610 MHz source counts and compare them to those measured at other radio
wavelengths. The well know flattening of the Euclidean-normalised 1.4 GHz
source counts below ~2 mJy, usually explained by a population of starburst
galaxies undergoing luminosity evolution, is seen at 610 MHz. The 610 MHz
source counts can be modelled by the same populations that explain the 1.4 GHz
source counts, assuming a spectral index of -0.7 for the starburst galaxies and
the steep spectrum AGN population. We find a similar dependence of luminosity
evolution on redshift for the starburst galaxies at 610 MHz as is found at 1.4
GHz (i.e. 'Q'= 2.45 (+0.3,-0.4)).
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 17:10:54 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Moss",
"D.",
""
],
[
"Seymour",
"N.",
""
],
[
"McHardy",
"I. M.",
""
],
[
"Dwelly",
"T.",
""
],
[
"Page",
"M. J.",
""
],
[
"Loaring",
"N. S.",
""
]
] |
0704.2052 | Vladimir Romanovsky | V. I. Romanovsky (1), S. A. Akimenko (1), G. I. Britvich (1), K. V.
Datsko (1), A. P. Filin (1), A. V. Inyakin (1), A. S. Konstantinov (1), I. Y.
Korolkov (1), V. A. Khmelnikov (1), V. M. Leontiev (1), V. P. Novikov (1), V.
F. Obraztsov (1), V. A. Polyakov (1), V. I. Shelikhov (1), O. G. Tchikilev
(1), V. A. Uvarov (1), O.P. Yushchenko (1), V. N. Bolotov (2), V. A. Duk (2),
S. V. Laptev (2), A. Yu. Polyarush (2) ((1) Institute for High Energy Physics
Protvino Russia, (2) Institute for Nuclear Research Moscow Russia) | Measurement of K^{-}_{e3} branching ratio | 10 pages, 8 figures | null | null | IHEP-2007-5 | hep-ex | null | The branching fraction for the decay $K^{-} \to \pi^{0} e \bar \nu$ is
measured using in-flight decays detected with {\bf ISTRA+} setup working at the
25 GeV negative secondary beam of the U-70 PS:\linebreak $Br_{K_{e3}}= (5.124
\pm 0.009 (stat) \pm 0.029(norm) \pm 0.030(syst))%$. From this value the
$|V_{us}|$ element of the CKM matrix is extracted, using previously measured
$f_{+}(t)$ form factor: $|V_{us}|=0.227 \pm 0.002$. The results are in
agreement with recent measurements by BNL E865, FNAL KTeV, KLOE.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 16:56:50 GMT"
},
{
"version": "v2",
"created": "Tue, 22 May 2007 07:30:23 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Romanovsky",
"V. I.",
""
],
[
"Akimenko",
"S. A.",
""
],
[
"Britvich",
"G. I.",
""
],
[
"Datsko",
"K. V.",
""
],
[
"Filin",
"A. P.",
""
],
[
"Inyakin",
"A. V.",
""
],
[
"Konstantinov",
"A. S.",
""
],
[
"Korolkov",
"I. Y.",
""
],
[
"Khmelnikov",
"V. A.",
""
],
[
"Leontiev",
"V. M.",
""
],
[
"Novikov",
"V. P.",
""
],
[
"Obraztsov",
"V. F.",
""
],
[
"Polyakov",
"V. A.",
""
],
[
"Shelikhov",
"V. I.",
""
],
[
"Tchikilev",
"O. G.",
""
],
[
"Uvarov",
"V. A.",
""
],
[
"Yushchenko",
"O. P.",
""
],
[
"Bolotov",
"V. N.",
""
],
[
"Duk",
"V. A.",
""
],
[
"Laptev",
"S. V.",
""
],
[
"Polyarush",
"A. Yu.",
""
]
] |
0704.2053 | Ran Wang | Ran Wang, Chris Carilli, Alexandre Beelen, Frank Bertoldi, Xiaohui
Fan, Fabian Walter, Karl M. Menten, Alain Omont, Pierre Cox, Michael A.
Strauss, Linhua Jiang | Millimeter and Radio Observations of z~6 Quasars | 27 pages including 6 figures. AJ accepted | null | 10.1086/518867 | null | astro-ph | null | We present millimeter and radio observations of 13 SDSS quasars at reshifts
z~6. We observed eleven of them with the Max-Planck Millimeter Bolometer Array
(MAMBO-2) at the IRAM 30m-telescope at 250 GHz and all of them with the Very
Large Array (VLA) at 1.4 GHz. Four sources are detected by MAMBO-2 and six are
detected by the VLA at >=3 sigma level. These sources, together with another 6
published in previous papers,yield a submillimeter/millimeter and radio
observed SDSS quasar sample at z~6. We use this sample to investigate the
far-infrared (FIR) andradio properties of optically bright quasars in the early
universe. We compare this sample to lower redshift samples of quasars observed
inthe submillimeter and millimeter wavelengths ((sub)mm), and find that the
distribution of the FIR to B band optical luminosity ratio (L_FIR/L_B) is
similar from z~2 to 6. We find a weak correlation between the FIR luminosity
(L_FIR) and B band optical luminosity (L_B) byincluding the (sub)mm observed
samples at all redshifts. Some strong (sub)mm detections in the z~6 sample have
radio-to-FIR ratios within the range defined by star forming galaxies, which
suggests possible co-eval star forming activity with the powerful AGN in these
sources. We calculate the rest frame radio to optical ratios (R*_1.4=L_{v,
1.4GHz}/L_{v, 4400A}) for all of the VLA observed sources in the z~6 quasar
sample. Only one radio detection in this sample, J083643.85+005453.3, has
R*_1.4~40 and can be considered radio loud. There are no strong radio sources
(R*_1.4>=100) among these SDSS quasars at z~6. These data are consistent with,
although do not set strong constraints on, a decreasing radio-loud quasar
fraction with increasing redshift.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 17:04:22 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wang",
"Ran",
""
],
[
"Carilli",
"Chris",
""
],
[
"Beelen",
"Alexandre",
""
],
[
"Bertoldi",
"Frank",
""
],
[
"Fan",
"Xiaohui",
""
],
[
"Walter",
"Fabian",
""
],
[
"Menten",
"Karl M.",
""
],
[
"Omont",
"Alain",
""
],
[
"Cox",
"Pierre",
""
],
[
"Strauss",
"Michael A.",
""
],
[
"Jiang",
"Linhua",
""
]
] |
0704.2054 | David Scherer | David R. Scherer | Vortex Formation by Merging and Interference of Multiple Trapped
Bose-Einstein Condensates | Ph.D. dissertation submitted to the University of Arizona, 178 pages
including 53 heavily compressed images; high resolution version is available
at http://www.optics.arizona.edu/Anderson/ | null | null | null | cond-mat.other | null | An apparatus for producing atomic-gas Bose-Einstein condensates (BECs) of
87-Rb atoms is described. The apparatus produces 87-Rb BECs in a dual-chamber
vacuum system that incorporates magnetic transport of trapped atoms from the
magneto-optical trapping cell to the BEC production cell via the operation of a
series of overlapping magnet coils. The design, construction, and operation of
the apparatus are described in detail. The apparatus is used to study the
creation of quantized vortices in BECs by the merging and interference of
multiple trapped condensates. In this experiment, a single harmonic potential
well is partitioned into three sections by an optical barrier, enabling the
simultaneous formation of three independent, uncorrelated BECs. The BECs may
either merge together during their growth, or, for high-energy barriers, the
BECs can be merged together by barrier removal after their formation. Either
process may instigate vortex formation in the resulting BEC, depending on the
initially indeterminate relative phases of the condensates and the merging
rate.
| [
{
"version": "v1",
"created": "Sun, 15 Apr 2007 21:39:23 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Scherer",
"David R.",
""
]
] |
0704.2055 | Paul Seidel | Paul Seidel | A biased view of symplectic cohomology | 37 pages, 2 figures; v2 has added references, slightly expanded
discussion of algorithmic recognizability, more balanced account of early
developments; v3 has clarifications in the discussion of equivariant
symplectic cohomology; v4 with terminology change (Liouville instead of
Weinstein), by popular request; v5, one nasty typo removed | null | null | null | math.SG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | These are lecture notes from my talks at the "Current Developments in
Mathematics" conference (Harvard, 2006). They cover a variety of topics
involving symplectic cohomology. In particular, a discussion of (algorithmic)
classification issues in symplectic and contact topology is included.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 18:00:36 GMT"
},
{
"version": "v2",
"created": "Sat, 21 Apr 2007 15:41:01 GMT"
},
{
"version": "v3",
"created": "Thu, 26 Apr 2007 19:54:06 GMT"
},
{
"version": "v4",
"created": "Mon, 2 Jul 2007 15:05:35 GMT"
},
{
"version": "v5",
"created": "Fri, 12 Feb 2010 17:44:43 GMT"
},
{
"version": "v6",
"created": "Mon, 15 Feb 2010 15:36:49 GMT"
}
] | 2010-02-15T00:00:00 | [
[
"Seidel",
"Paul",
""
]
] |
0704.2056 | Mohammadreza Hadizadeh | M. R. Hadizadeh and S. Bayegan | Bound State Calculations of the Three-Dimensional Yakubovsky Equations
with the inclusion of Three-Body Forces | 23 pages, 2 eps figures, 5 tables. Major changes; version to appear
in European Physical Journal A | Eur. Phys. J. A 36, 201-209 (2008) | 10.1140/epja/i2008-10583-8 | null | nucl-th | null | The four-body Yakubovsky equations in a Three-Dimensional approach with the
inclusion of the three-body forces is proposed. The four-body bound state with
two- and three-body interactions is formulated in Three-Dimensional approach
for identical particles as function of vector Jacobi momenta, specifically the
magnitudes of the momenta and the angles between them. The modified three
dimensional Yakubovsky integral equations is successfully solved with the
scalar two-meson exchange three-body force where the Malfliet-Tjon-type
two-body force is implemented. The three-body force effects on the energy
eigenvalue and the four-body wave function, as well as accuracy of our
numerical calculations are presented.The four-body Yakubovsky equations in a
Three-Dimensional approach with the inclusion of the three-body forces is
proposed. The four-body bound state with two- and three-body interactions is
formulated in Three-Dimensional approach for identical particles as function of
vector Jacobi momenta, specifically the magnitudes of the momenta and the
angles between them. The modified three dimensional Yakubovsky integral
equations is successfully solved with the scalar two-meson exchange three-body
force where the Malfliet-Tjon-type two-body force is implemented. The
three-body force effects on the energy eigenvalue and the four-body wave
function, as well as accuracy of our numerical calculations are presented.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 18:01:09 GMT"
},
{
"version": "v2",
"created": "Tue, 29 Apr 2008 14:37:08 GMT"
}
] | 2008-05-25T00:00:00 | [
[
"Hadizadeh",
"M. R.",
""
],
[
"Bayegan",
"S.",
""
]
] |
0704.2057 | Pauline Barmby | P. Barmby, D.E. McLaughlin, W.E. Harris, G.L.H. Harris, D.A. Forbes | Structural parameters for globular clusters in M31 and generalizations
for the fundamental plane | AJ in press; 59 pages including 16 figures | Astron.J.133:2764-2786,2007 | 10.1086/516777 | null | astro-ph | null | The structures of globular clusters (GCs) reflect their dynamical states and
past histories. High-resolution imaging allows the exploration of morphologies
of clusters in other galaxies. Surface brightness profiles from new Hubble
Space Telescope observations of 34 globular clusters in M31 are presented,
together with fits of several different structural models to each cluster. M31
clusters appear to be adequately fit by standard King models, and do not
obviously require alternate descriptions with relatively stronger halos, such
as are needed to fit many GCs in other nearby galaxies. The derived structural
parameters are combined with corrected versions of those measured in an earlier
survey to construct a comprehensive catalog of structural and dynamical
parameters for M31 GCs with a sample size similar to that for the Milky Way.
Clusters in M31, the Milky Way, Magellanic Clouds, Fornax dwarf spheroidal and
NGC 5128 define a very tight fundamental plane with identical slopes. The
combined evidence for these widely different galaxies strongly reinforces the
view that old globular clusters have near-universal structural properties
regardless of host environment.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 18:01:15 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Barmby",
"P.",
""
],
[
"McLaughlin",
"D. E.",
""
],
[
"Harris",
"W. E.",
""
],
[
"Harris",
"G. L. H.",
""
],
[
"Forbes",
"D. A.",
""
]
] |
0704.2058 | Craig DeForest | Craig E. DeForest, Charles C. Kankelborg | The Sensitivity of Hybrid Differential Stereoscopy for Spectral Imaging | Submitted to APJ Suppl. Ser | null | null | null | astro-ph | null | Stereoscopic spectral imaging is an observing technique that affords rapid
acquisition of limited spectral information over an entire image plane
simultaneously. Light from a telescope is dispersed into multiple spectral
orders, which are imaged separately, and two or more of the dispersed images
are combined using an analogy between the (x,y,\lambda) spectral data space and
conventional (x,y,z) three-space. Because no photons are deliberately destroyed
during image acquisition, the technique is much more photon-efficient in some
observing regimes than existing techniques such as scanned-filtergraph or
scanned-slit spectral imaging. Hybrid differential stereoscopy, which uses a
combination of conventional cross-correlation stereoscopy and linear
approximation theory to extract the central wavelength of a spectral line, has
been used to produce solar Stokes-V (line-of-sight) magnetograms in the 617.34
nm Fe I line, and more sophisticated inversion techniques are currently being
used to derive Doppler and line separation data from EUV images of the solar
corona collected in the neighboring lines of He-II and Si-XI at 30.4 nm. In
this paper we develop an analytic a priori treatment of noise in the line shift
signal derived from hybrid differential stereoscopy. We use the analysis to
estimate the noise level and measurement precision in a high resolution solar
magnetograph based on stereoscopic spectral imaging, compare those estimates to
a test observation made in 2003, and discuss implications for future
instruments.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 19:48:27 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"DeForest",
"Craig E.",
""
],
[
"Kankelborg",
"Charles C.",
""
]
] |
0704.2059 | Joannah L. Hinz | J. L. Hinz, M. J. Rieke, G. H. Rieke, C. N. A. Willmer, K. Misselt, C.
W. Engelbracht, M. Blaylock (U. Arizona), T. E. Pickering (MMTO) | Spitzer Observations of Low Luminosity Isolated and Low Surface
Brightness Galaxies | 20 pages, 8 figures, accepted to ApJ | Astrophys.J.663:895-907,2007 | 10.1086/518817 | null | astro-ph | null | We examine the infrared properties of five low surface brightness galaxies
(LSBGs) and compare them with related but higher surface brightness galaxies,
using Spitzer Space Telescope images and spectra. All the LSBGs are detected in
the 3.6 and 4.5um bands, representing the stellar population. All but one are
detected at 5.8 and 8.0um, revealing emission from hot dust and aromatic
molecules, though many are faint or point-like at these wavelengths. Detections
of LSBGs at the far-infrared wavelengths, 24, 70, and 160um, are varied in
morphology and brightness, with only two detections at 160um, resulting in
highly varied spectral energy distributions. Consistent with previous
expectations for these galaxies, we find that detectable dust components exist
for only some LSBGs, with the strength of dust emission dependent on the
existence of bright star forming regions. However, the far-infrared emission
may be relatively weak compared with normal star-forming galaxies.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 18:18:40 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Hinz",
"J. L.",
"",
"U. Arizona"
],
[
"Rieke",
"M. J.",
"",
"U. Arizona"
],
[
"Rieke",
"G. H.",
"",
"U. Arizona"
],
[
"Willmer",
"C. N. A.",
"",
"U. Arizona"
],
[
"Misselt",
"K.",
"",
"U. Arizona"
],
[
"Engelbracht",
"C. W.",
"",
"U. Arizona"
],
[
"Blaylock",
"M.",
"",
"U. Arizona"
],
[
"Pickering",
"T. E.",
"",
"MMTO"
]
] |
0704.2060 | Tayseer Abu Alrub T. Abu Alrub | T. R. Abu Alrub, S. H. Curnoe | Symmetry properties of the nodal superconductor PrOs4Sb12 | to appear in Phys. Rev. B 76 | Phys. Rev. B 76, 054514 (2007) | 10.1103/PhysRevB.76.054514 | null | cond-mat.supr-con | null | We present a theoretical study of the superconducting gap function in
PrOs4Sb12 using a symmetry-based approach. A three-component order parameter in
the triplet channel best describes superconductivity. The gap function is
non-degenerate and the lower branch has four cusp nodes at unusual points of
the Fermi surface, which lead to power law behaviours in the density of states,
specific heat and nuclear spin relaxation rate.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 19:25:41 GMT"
},
{
"version": "v2",
"created": "Mon, 6 Aug 2007 01:07:25 GMT"
}
] | 2011-11-09T00:00:00 | [
[
"Alrub",
"T. R. Abu",
""
],
[
"Curnoe",
"S. H.",
""
]
] |
0704.2061 | Fedir Kyrychenko | F.V. Kyrychenko and C.A. Ullrich | Memory function formalism approach to electrical conductivity and
optical response of dilute magnetic semiconductors | Proceedings of the 13th Brazilian Workshop on Semiconductors Physics | null | null | null | cond-mat.mtrl-sci | null | A combination of the memory function formalism and time-dependent
density-functional theory is applied to transport in dilute magnetic
semiconductors. The approach considers spin and charge disorder and
electron-electron interaction on an equal footing. Within the weak disorder
limit and using a simple parabolic approximation for the valence band we show
that Coulomb and exchange scattering contributions to the resistivity in GaMnAs
are of the same order of magnitude. The positional correlations of defects
result in a significant increase of Coulomb scattering, while the suppression
of localized spin fluctuations in the ferromagnetic phase contributes
substantially to the experimentally observed drop of resistivity below T_c. A
proper treatment of dynamical screening and collective excitations is essential
for an accurate description of infrared absorption.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 19:34:15 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Kyrychenko",
"F. V.",
""
],
[
"Ullrich",
"C. A.",
""
]
] |
0704.2062 | Sergiu Vacaru I. | Sergiu I. Vacaru | Nonholonomic Ricci Flows: III. Curve Flows and Solitonic Hierarchies | 47 pages, latex2e [12pt], version 2 with minor grammar modifications | null | null | null | math.DG gr-qc hep-th math-ph math.MP nlin.SI | null | The geometric constructions are elaborated on (semi) Riemannian manifolds and
vector bundles provided with nonintegrable distributions defining nonlinear
connection structures induced canonically by metric tensors. Such spaces are
called nonholonomic manifolds and described by two equivalent linear
connections also induced in unique forms by a metric tensor (the Levi Civita
and the canonical distinguished connection, d-connection). The lifts of
geometric objects on tangent bundles are performed for certain classes of
d-connections and frame transforms when the Riemann tensor is parametrized by
constant matrix coefficients. For such configurations, the flows of
non-stretching curves and corresponding bi-Hamilton and solitonic hierarchies
encode information about Ricci flow evolution, Einstein spaces and exact
solutions in gravity and geometric mechanics. The applied methods were
elaborated formally in Finsler geometry and allows us to develop the formalism
for generalized Riemann-Finsler and Lagrange spaces. Nevertheless, all
geometric constructions can be equivalently re-defined for the Levi Civita
connections and holonomic frames on (semi) Riemannian manifolds.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 23:08:08 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Apr 2007 22:36:47 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Vacaru",
"Sergiu I.",
""
]
] |
0704.2063 | Tsvi Piran | Yi-Zhong Fan, Tsvi Piran, Ramesh Narayan and Da-Ming Wei | High Energy Afterglow from Gamma-ray Bursts | 15 pages, 15 eps figures and 1 table, slightly modified version to
appear in MNRAS. Fig.12 is added to illustrate the difference of the EIC
emission lightcurves with and without the anisotropic correction in the
comoving frame of the blast wave | Mon.Not.Roy.Astron.Soc. 384 (2008) 1483-1501 | 10.1111/j.1365-2966.2007.12765.x | null | astro-ph | null | We calculate the very high energy (sub-GeV to TeV) inverse Compton emission
of GRB afterglows. We argue that this emission provides a powerful test of the
currently accepted afterglow model. We focus on two processes: synchrotron
self-Compton (SSC) emission within the afterglow blast wave, and external
inverse Compton (EIC) emission which occurs when flare photons (produced by an
internal process) pass through the blast wave. We show that if our current
interpretations of the Swift XRT data are correct, there should be a canonical
high energy afterglow emission light curve. Our predictions can be tested with
high energy observatories such as GLAST, Whipple, H.E.S.S. and MAGIC. Under
favorable conditions we expect afterglow detections in all these detectors.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 08:09:01 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Dec 2007 16:42:22 GMT"
},
{
"version": "v3",
"created": "Wed, 26 Dec 2007 12:18:49 GMT"
}
] | 2008-03-04T00:00:00 | [
[
"Fan",
"Yi-Zhong",
""
],
[
"Piran",
"Tsvi",
""
],
[
"Narayan",
"Ramesh",
""
],
[
"Wei",
"Da-Ming",
""
]
] |
0704.2064 | Eric Linder | Eric V. Linder | The Dynamics of Quintessence, The Quintessence of Dynamics | 15 pages, 6 figures, review article for General Relativity and
Gravitation; v2 minor changes to match journal version | Gen.Rel.Grav.40:329-356,2008 | 10.1007/s10714-007-0550-z | null | astro-ph | null | Quintessence theories for cosmic acceleration imbue dark energy with a
non-trivial dynamics that offers hope in distinguishing the physical origin of
the component. We review quintessence models with an emphasis on this dynamics
and discuss classifications of the different physical behaviors. The pros and
cons of various parameterizations are examined as well as the extension from
scalar fields to other modifications of the Friedmann expansion equation. New
results on the ability of cosmological data to distinguish among and between
thawing and freezing fields are presented.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 20:00:05 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 19:36:11 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Linder",
"Eric V.",
""
]
] |
0704.2065 | Jonathan A. Jones | J. A. Jones | Comment on "NMR Experiment Factors Numbers with Gauss Sums" | 1 page RevTex4; submitted to PRL | null | null | null | quant-ph | null | Mehring et al. have recently described an elegant nuclear magnetic resonance
(NMR) experiment implementing an algorithm to factor numbers based on the
properties of Gauss sums. Similar experiments have also been described by
Mahesh et al. In fact these algorithms do not factor numbers directly, but
rather check whether a trial integer $\ell$ is a factor of a given integer $N$.
Here I show that these NMR schemes cannot be used for factor checking without
first implicitly determining whether or not $\ell$ is a factor of $N$.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 20:00:42 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Jones",
"J. A.",
""
]
] |
0704.2066 | Dominic William Berry | Dominic W. Berry | Lower bounds for communication capacities of two-qudit unitary
operations | 9 pages, 2 figures, comments welcome | null | 10.1103/PhysRevA.76.062302 | null | quant-ph | null | We show that entangling capacities based on the Jamiolkowski isomorphism may
be used to place lower bounds on the communication capacities of arbitrary
bipartite unitaries. Therefore, for these definitions, the relations which have
been previously shown for two-qubit unitaries also hold for arbitrary
dimensions. These results are closely related to the theory of the
entanglement-assisted capacity of channels. We also present more general
methods for producing ensembles for communication from initial states for
entanglement creation.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 06:34:13 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Berry",
"Dominic W.",
""
]
] |
0704.2067 | Spyros Avramis | Spyros D. Avramis, Konstadinos Sfetsos, Dimitrios Zoakos | Complex marginal deformations of D3-brane geometries, their Penrose
limits and giant gravitons | 53 pages, 5 figures; v3: version to appear in Nucl. Phys. B | Nucl.Phys.B787:55-97,2007 | 10.1016/j.nuclphysb.2007.07.017 | null | hep-th | null | We apply the Lunin--Maldacena construction of gravity duals to beta-deformed
gauge theories to a class of Type IIB backgrounds with U(1)^3 global symmetry,
which include the multicenter D3-brane backgrounds dual to the Coulomb branch
of N=4 super Yang-Mills and the rotating D3-brane backgrounds dual to the
theory at finite temperature and chemical potential. After a general
discussion, we present the full form of the deformed metrics for three special
cases, which can be used for the study of various aspects of the
marginally-deformed gauge theories. We also construct the Penrose limits of the
solutions dual to the Coulomb branch along a certain set of geodesics and, for
the resulting PP--wave metrics, we examine the effect of beta-deformations on
the giant graviton states. We find that giant gravitons exist only up to a
critical value of the sigma-deformation parameter, are not degenerate in energy
with the point graviton, and remain perturbatively stable. Finally, we probe
the sigma-deformed multicenter solutions by examining the static heavy-quark
potential by means of Wilson loops. We find situations that give rise to
complete screening as well as linear confinement, with the latter arising is an
intriguing way reminiscent of phase transitions in statistical systems.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 20:24:49 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Apr 2007 11:04:51 GMT"
},
{
"version": "v3",
"created": "Thu, 16 Aug 2007 20:18:43 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Avramis",
"Spyros D.",
""
],
[
"Sfetsos",
"Konstadinos",
""
],
[
"Zoakos",
"Dimitrios",
""
]
] |
0704.2068 | Vianney Lebouteiller | V. Lebouteiller, B. Brandl, J. Bernard-Salas, D. Devost, J. R. Houck | PAH Strength and the Interstellar Radiation Field around the Massive
Young Cluster NGC3603 | Accepted for publication in ApJ. Corrected typos | Astrophys.J.665:390-401,2007 | 10.1086/519014 | null | astro-ph | null | We present spatial distribution of polycyclic aromatic hydrocarbons and
ionized gas within the Galactic giant HII region NGC3603. Using the IRS
instrument on board the Spitzer Space Telescope, we study in particular the PAH
emission features at ~5.7, 6.2, 7.7, 8.6, and 11.3um, and the [ArII] 6.99um,
[NeII] 12.81um, [ArIII] 8.99um, and [SIV] 10.51um forbidden emission lines. The
observations probe both ionized regions and photodissociation regions. Silicate
emission is detected close to the central cluster while silicate absorption is
seen further away. We find no significant variation of the PAH ionization
fraction across the whole region. The emission of very small grains lies closer
to the central stellar cluster than emission of PAHs. The PAH/VSG ratio
anticorrelates with the hardness of the interstellar radiation field suggesting
a destruction mechanism of the molecules within the ionized gas, as shown for
low-metallicity galaxies by Madden et al. (2006).
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 20:03:35 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Apr 2007 15:40:20 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Lebouteiller",
"V.",
""
],
[
"Brandl",
"B.",
""
],
[
"Bernard-Salas",
"J.",
""
],
[
"Devost",
"D.",
""
],
[
"Houck",
"J. R.",
""
]
] |
0704.2069 | Charles Young | C. A. S. Young | q-Deformed Supersymmetry and Dynamic Magnon Representations | 15 pages, LaTeX; (v2) references added | J.Phys.A40:9165-9176,2007 | 10.1088/1751-8113/40/30/033 | DCPT-07/09 | hep-th | null | It was recently noted that the dispersion relation for the magnons of planar
N=4 SYM can be identified with the Casimir of a certain deformation of the
Poincare algebra, in which the energy and momentum operators are supplemented
by a boost generator J. By considering the relationship between J and su(2|2) x
R^2, we derive a q-deformed super-Poincare symmetry algebra of the kinematics.
Using this, we show that the dynamic magnon representations may be obtained by
boosting from a fixed rest-frame representation. We comment on aspects of the
coalgebra structure and some implications for the question of boost-covariance
of the S-matrix.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 16:23:24 GMT"
},
{
"version": "v2",
"created": "Tue, 24 Apr 2007 10:39:45 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Young",
"C. A. S.",
""
]
] |
0704.2070 | Elias C. Vagenas | M. R. Setare, Elias C. Vagenas | The Cosmological Dynamics of Interacting Holographic Dark Energy Model | v1: 9 pages, LaTeX; v2: 12 pages, comments and clarifications added,
to appear in IJMPD | Int.J.Mod.Phys.D18:147-157,2009 | 10.1142/S0218271809014303 | null | hep-th astro-ph gr-qc | null | Motivated by the recent observations for the cosmic acceleration and the
suitable evolution of the Universe provided an interaction (decay of dark
energy to matter) is incorporated in a cosmological model, we study the
cosmological evolution of the Interacting Holographic Dark Energy scenario.
Critical points are derived and their corresponding cosmological models are
presented. The dynamical character of these models is revealed.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 20:59:40 GMT"
},
{
"version": "v2",
"created": "Tue, 29 Apr 2008 05:30:24 GMT"
}
] | 2009-03-24T00:00:00 | [
[
"Setare",
"M. R.",
""
],
[
"Vagenas",
"Elias C.",
""
]
] |
0704.2071 | Tomasz Taylor | Tomasz R. Taylor | Non-commutative Field Theory with Twistor-like Coordinates | Momentum-dependence of the propagator and more details. Final version
for Physics Letters B | Phys.Lett.B656:141-144,2007 | 10.1016/j.physletb.2007.09.014 | null | hep-th gr-qc math-ph math.MP | null | We consider quantum field theory in four-dimensional Minkowski spacetime,
with the position coordinates represented by twistors instead of the usual
world-vectors. Upon imposing canonical commutation relations between twistors
and dual twistors, quantum theory of fields described by non-holomorphic
functions of twistor variables becomes manifestly non-commutative, with Lorentz
symmetry broken by a time-like vector. We discuss the free field propagation
and its impact on the short- and long-distance behavior of physical amplitudes
in perturbation theory. In the ultraviolet limit, quantum field theories in
twistor space are generically less divergent than their commutative
counterparts. Furthermore, there is no infrared--ultraviolet mixing problem.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 21:00:24 GMT"
},
{
"version": "v2",
"created": "Sun, 16 Sep 2007 23:01:12 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Taylor",
"Tomasz R.",
""
]
] |
0704.2072 | Peter Kammel | V.A. Andreev, T.I. Banks, T.A. Case, D.B. Chitwood, S.M. Clayton, K.M.
Crowe, J. Deutsch, J. Egger, S.J. Freedman, V.A. Ganzha, T. Gorringe, F.E.
Gray, D.W. Hertzog, M. Hildebrandt, P. Kammel, B. Kiburg, S. Knaack, P.A.
Kravtsov, A.G. Krivshich, B. Lauss, K.L. Lynch, E.M. Maev, O.E. Maev, F.
Mulhauser, C.S. \"Ozben, C. Petitjean, G.E. Petrov, R. Prieels, G.N.
Schapkin, G.G. Semenchuk, M.A. Soroka, V. Tishchenko, A.A. Vasilyev, A.A.
Vorobyov, M.E. Vznuzdaev, P. Winter | Measurement of the Rate of Muon Capture in Hydrogen Gas and
Determination of the Proton's Pseudoscalar Coupling $g_P$ | submitted to Phys.Rev.Lett | Phys.Rev.Lett.99:032002,2007 | 10.1103/PhysRevLett.99.032002 | null | nucl-ex | null | The rate of nuclear muon capture by the proton has been measured using a new
experimental technique based on a time projection chamber operating in
ultra-clean, deuterium-depleted hydrogen gas at 1 MPa pressure. The capture
rate was obtained from the difference between the measured $\mu^-$
disappearance rate in hydrogen and the world average for the $\mu^+$ decay
rate. The target's low gas density of 1% compared to liquid hydrogen is key to
avoiding uncertainties that arise from the formation of muonic molecules. The
capture rate from the hyperfine singlet ground state of the $\mu p$ atom is
measured to be $\Lambda_S=725.0 \pm 17.4 s^{-1}$, from which the induced
pseudoscalar coupling of the nucleon, $g_P(q^2=-0.88 m_\mu^2)=7.3 \pm 1.1$, is
extracted. This result is consistent with theoretical predictions for $g_P$
that are based on the approximate chiral symmetry of QCD.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 21:26:49 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Andreev",
"V. A.",
""
],
[
"Banks",
"T. I.",
""
],
[
"Case",
"T. A.",
""
],
[
"Chitwood",
"D. B.",
""
],
[
"Clayton",
"S. M.",
""
],
[
"Crowe",
"K. M.",
""
],
[
"Deutsch",
"J.",
""
],
[
"Egger",
"J.",
""
],
[
"Freedman",
"S. J.",
""
],
[
"Ganzha",
"V. A.",
""
],
[
"Gorringe",
"T.",
""
],
[
"Gray",
"F. E.",
""
],
[
"Hertzog",
"D. W.",
""
],
[
"Hildebrandt",
"M.",
""
],
[
"Kammel",
"P.",
""
],
[
"Kiburg",
"B.",
""
],
[
"Knaack",
"S.",
""
],
[
"Kravtsov",
"P. A.",
""
],
[
"Krivshich",
"A. G.",
""
],
[
"Lauss",
"B.",
""
],
[
"Lynch",
"K. L.",
""
],
[
"Maev",
"E. M.",
""
],
[
"Maev",
"O. E.",
""
],
[
"Mulhauser",
"F.",
""
],
[
"Özben",
"C. S.",
""
],
[
"Petitjean",
"C.",
""
],
[
"Petrov",
"G. E.",
""
],
[
"Prieels",
"R.",
""
],
[
"Schapkin",
"G. N.",
""
],
[
"Semenchuk",
"G. G.",
""
],
[
"Soroka",
"M. A.",
""
],
[
"Tishchenko",
"V.",
""
],
[
"Vasilyev",
"A. A.",
""
],
[
"Vorobyov",
"A. A.",
""
],
[
"Vznuzdaev",
"M. E.",
""
],
[
"Winter",
"P.",
""
]
] |
0704.2073 | Allard Jan van Marle | A. J. van Marle, N. Langer, G. garcia-Segura | Constraints on gamma-ray burst and supernova progenitors through
circumstellar absorption lines. (II): Post-LBV Wolf-Rayet stars | accepted for publication by A&A | null | 10.1051/0004-6361:20077207 | null | astro-ph | null | Van Marle et al. (2005) showed that circumstellar absorption lines in early
Type Ib/c supernova and gamma-ray burst afterglow spectra may reveal the
progenitor evolution of the exploding Wolf-Rayet star. While the quoted paper
deals with Wolf-Rayet stars which evolved through a red supergiant stage, we
investigate here the initially more massive Wolf-Rayet stars which are thought
to evolve through a Luminous Blue Variable (LBV) stage. We perform hydrodynamic
simulations of the evolution of the circumstellar medium around a 60 Msol star,
from the main sequence through the LBV and Wolf-Rayet stages, up to core
collapse. We then compute the column density of the circumstellar matter as a
function of radial velocity, time and angle. This allows a comparison with the
number and blue-shifts, of absorption components in the spectra of LBVs,
Wolf-Rayet stars, Type Ib/c supernovae and gamma-ray burst afterglows. Our
simulation for the post-LBV stage shows the formation of various absorption
components, which are, however, rather short lived; they dissipate on time
scales shorter than 50,000yr. As the LBV stage is thought to occur at the
beginning of core helium burning, the remaining Wolf-Rayet life time is
expected to be one order of magnitude larger. When interpreting the absorption
components in the afterglow spectrum of GRB-021004 as circumstellar, it can be
concluded that the progenitor of this source did most likely not evolve through
an LBV stage. However, a close binary with late common-envelope phase (Case C)
may produce a circumstellar medium that closely resembles the LBV to Wolf-Rayet
evolution, but with a much shorter Wolf-Rayet period.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 21:23:17 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"van Marle",
"A. J.",
""
],
[
"Langer",
"N.",
""
],
[
"garcia-Segura",
"G.",
""
]
] |
0704.2074 | Wim de Vries | W. H. de Vries (1,2), J. A. Hodge (1), R. H. Becker (1,2), R. L. White
(3), and D. J. Helfand (4)((1) University of California, Davis, (2) IGPP,
Lawrence Livermore National Laboratory, Livermore,(3) Space Telescope Science
Institute, Baltimore, (4) Columbia University, New York) | Star-Formation in Low Radio Luminosity AGN from the Sloan Digital Sky
Survey | Accepted for publication in Astronomical Journal; 15 pages, 8 color
figures | Astron.J.134:457-465,2007 | 10.1086/518866 | null | astro-ph | null | We investigate faint radio emission from low- to high-luminosity Active
Galactic Nuclei (AGN) selected from the Sloan Digital Sky Survey (SDSS). Their
radio properties are inferred by co-adding large ensembles of radio image
cut-outs from the FIRST survey, as almost all of the sources are individually
undetected. We correlate the median radio flux densities against a range of
other sample properties, including median values for redshift, [OIII]
luminosity, emission line ratios, and the strength of the 4000A break. We
detect a strong trend for sources that are actively undergoing star-formation
to have excess radio emission beyond the ~10^28 ergs/s/Hz level found for
sources without any discernible star-formation. Furthermore, this additional
radio emission correlates well with the strength of the 4000A break in the
optical spectrum, and may be used to assess the age of the star-forming
component. We examine two subsamples, one containing the systems with emission
line ratios most like star-forming systems, and one with the sources that have
characteristic AGN ratios. This division also separates the mechanism
responsible for the radio emission (star-formation vs. AGN). For both cases we
find a strong, almost identical, correlation between [OIII] and radio
luminosity, with the AGN sample extending toward lower, and the star-formation
sample toward higher luminosities. A clearer separation between the two
subsamples is seen as function of the central velocity dispersion of the host
galaxy. For systems with similar redshifts and velocity dispersions, the
star-formation subsample is brighter than the AGN in the radio by an order of
magnitude. This underlines the notion that the radio emission in star-forming
systems can dominate the emission associated with the AGN.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 21:40:40 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"de Vries",
"W. H.",
""
],
[
"Hodge",
"J. A.",
""
],
[
"Becker",
"R. H.",
""
],
[
"White",
"R. L.",
""
],
[
"Helfand",
"D. J.",
""
]
] |
0704.2075 | Grzegorz Pietrzynski | G. Pietrzynski, W. Gieren, A. Udalski, I. Soszynski, F. Bresolin, R.P.
Kudritzki, A. Garcia, D. Minniti, R. Mennickent, O. Szewczyk, M. Szymanski,
M. Kubiak, L. Wyrzykowski | The Araucaria Project. The Distance to the Local Group Galaxy WLM from
Cepheid Variables discovered in a Wide-Field Imaging Survey | AJ accepted | Astron.J.134:594-603,2007 | 10.1086/518599 | null | astro-ph | null | We have conducted an extensive wide-field imaging survey for Cepheid
variables in the Local Group irregular galaxy WLM. From data obtained on 101
nights, we have discovered 60 Cepheids which include 14 of the 15 Cepheid
variables previously detected by Sandage and Carlson. Down to a period of 3
days, our Cepheid survey in WLM should be practically complete. Importantly, we
have found for the first time a long-period Cepheid (P=54.2 days) in this
galaxy, alleviating the puzzle that WLM with its many blue, massive stars does
not contain Cepheids with periods longer than about 10 days. Our data define
tight period-luminosity relations in V, I and the reddening-free Wesenheit
magnitude ${\rm W}_{\rm I}$ which are all extremely well fit by the
corresponding slopes of the LMC Cepheid PL relation, suggesting no change of
the PL relation slope down to a Cepheid metal abundance of about -1.0 dex, in
agreement with other recent studies. We derive a true distance modulus to WLM
of 25.144 $\pm$0.03 (r) $\pm$0.07 (s) mag from our data, in good agreement with
the earlier 24.92 $\pm$ 0.21 mag determination of Lee, Freedman and Madore
(1993a) from Cepheid variables. The quoted value of the systematic uncertainty
does not include the contribution from the LMC distance which we have assumed
to be 18.50 mag, as in the previous papers in our project.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 21:49:55 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Pietrzynski",
"G.",
""
],
[
"Gieren",
"W.",
""
],
[
"Udalski",
"A.",
""
],
[
"Soszynski",
"I.",
""
],
[
"Bresolin",
"F.",
""
],
[
"Kudritzki",
"R. P.",
""
],
[
"Garcia",
"A.",
""
],
[
"Minniti",
"D.",
""
],
[
"Mennickent",
"R.",
""
],
[
"Szewczyk",
"O.",
""
],
[
"Szymanski",
"M.",
""
],
[
"Kubiak",
"M.",
""
],
[
"Wyrzykowski",
"L.",
""
]
] |
0704.2076 | Jiannis Pachos | Paolo Maraner and Jiannis K. Pachos | Universal Features of Dimensional Reduction Schemes from General
Covariance Breaking | 16 pages, no figures, references added | AnnalsPhys.323:2044-2072,2008 | 10.1016/j.aop.2007.11.004 | null | hep-th gr-qc math-ph math.DG math.MP quant-ph | null | Many features of dimensional reduction schemes are determined by the breaking
of higher dimensional general covariance associated with the selection of a
particular subset of coordinates. By investigating residual covariance we
introduce lower dimensional tensors --generalizing to one side Kaluza-Klein
gauge fields and to the other side extrinsic curvature and torsion of embedded
spaces-- fully characterizing the geometry of dimensional reduction. We obtain
general formulas for the reduction of the main tensors and operators of
Riemannian geometry. In particular, we provide what is probably the maximal
possible generalization of Gauss, Codazzi and Ricci equations and various other
standard formulas in Kaluza-Klein and embedded spacetimes theories. After
general covariance breaking, part of the residual covariance is perceived by
effective lower dimensional observers as an infinite dimensional gauge group.
This reduces to finite dimensions in Kaluza-Klein and other few remarkable
backgrounds, all characterized by the vanishing of appropriate lower
dimensional tensors.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 21:55:20 GMT"
},
{
"version": "v2",
"created": "Sun, 14 Oct 2007 15:29:45 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Maraner",
"Paolo",
""
],
[
"Pachos",
"Jiannis K.",
""
]
] |
0704.2077 | Jeff Tallon | N. Suresh and J.L. Tallon | Thermodynamic properties of Pb determined from pressure-dependent
critical-field measurements | 5 pages, 6 figures, in press Phys. Rev. B | null | 10.1103/PhysRevB.75.174502 | null | cond-mat.supr-con | null | We have carried out extensive low-temperature (1.5 to 10 K) measurements of
the critical field, $H_c$, for the element Pb up to a pressure of $P=1.2$ GPa.
From this data the electronic entropy, specific heat, thermal expansion
coefficient and compressibility is calculated as a function of temperature,
pressure and magnetic field. The zero-field data is consistent with direct
thermodynamic measurements and the $P$-dependence of $T_c$ and specific heat
coefficient, $\gamma(T,P)$ allows the determination of the $P$-dependence of
the pairing interaction.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 23:17:16 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Suresh",
"N.",
""
],
[
"Tallon",
"J. L.",
""
]
] |
0704.2078 | John Hegseth | John Hegseth | Quantum theory from Hamilton's Principle with imperfect information | 4 pages, 3 figures | null | null | null | quant-ph | null | Many quantization schemes rely on analogs of classical mechanics where the
connections with classical mechanics are indirect. In this work I propose a new
and direct connection between classical mechanics and quantum mechanics where
the quantum mechanical propagator is derived from a variational principle. This
principle allows a physical system to have imperfect information, i.e., there
is incomplete knowledge of the physical state, and many paths are allowed.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 23:13:37 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Hegseth",
"John",
""
]
] |
0704.2079 | George Pavlov | G. G. Pavlov, O. Kargaltsev, G. P. Garmire, A. Wolszczan | X-ray emission from the planet pulsar B1257+12 | 8 pages, 4 figures, emulateapj.sty; accepted for publication in
Astrophysical Journal | Astrophys.J.664:1072-1078,2007 | 10.1086/518926 | null | astro-ph | null | We report the detection of the millisecond pulsar B1257+12 with the Chandra
X-ray Observatory. In a 20 ks exposure we detected 25 photons from the pulsar,
with energies between 0.4 and 2.0 keV, corresponding to the flux F_X=(4.4+/-
0.9)*10^{-15} ergs s^{-1} cm^{-2} in this energy range. The X-ray spectrum can
be described by a power-law model with photon index Gamma = 2.8 and luminosity
L_X \approx 2.5*10^{29} ergs s^{-1} in the 0.3--8 keV band, for a plausible
distance of 500 pc and hydrogen column density N_H=3*10^{20} cm^{-2}.
Alternatively, the spectrum can be fitted by a blackbody model with kT ~ 0.22
keV and projected emitting area ~2000 m^2. If the thermal X-rays are emitted
from two symmetric polar caps, the bolometric luminosity of the two caps is 2
L_bol ~ 3*10^{29} ergs s^{-1}. We compared our results with the data on other
30 millisecond pulsars observed in X-rays and found that the apparent X-ray
efficiency of PSR B1257+12, L_X/Edot ~ 3*10^{-5} for d=500 pc, is lower than
those of most of millisecond pulsars. This might be explained by an unfavorable
orientation of the X-ray pulsar beam if the radiation is magnetospheric, or by
strong asymmetry of polar caps if the radiation is thermal (e.g., one of the
polar caps is much brighter than the other and remains invisible for most part
of the pulsar period). Alternatively, it could be attributed to absorption of
X-rays in circumpulsar matter, such as a flaring debris disk left over after
formation of the planetary system around the pulsar.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 14:59:44 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Pavlov",
"G. G.",
""
],
[
"Kargaltsev",
"O.",
""
],
[
"Garmire",
"G. P.",
""
],
[
"Wolszczan",
"A.",
""
]
] |
0704.2080 | Romulus Godang | The BABAR Collaboration: B. Aubert, et al | Measurement of the Absolute Branching Fraction of D0 --> K- pi+ | Revtex4, 7 pages, 2 figures, accepted by Physical Review Letters | Phys.Rev.Lett.100:051802,2008 | 10.1103/PhysRevLett.100.051802 | BABAR-PUB-07/011, SLAC-PUB-12463 | hep-ex | null | We measure the absolute branching fraction for D0 --> K- pi+ using partial
reconstruction of B0bar --> D^{*+} X \ell^{-} \bar{\nu}_{\ell} decays, in which
only the charged lepton and the pion from the decay D^{*+} --> D0 pi^+ are
used. Based on a data sample of 230 million B Bbar pairs collected at the
Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B
Factory at SLAC, we obtain the absolute branching fractions of D0 --> K- pi+ =
(4.007 \pm 0.037 \pm 0.072)%, where the first uncertainty is statistical and
the second is systematic.
| [
{
"version": "v1",
"created": "Mon, 16 Apr 2007 23:44:50 GMT"
},
{
"version": "v2",
"created": "Thu, 31 Jan 2008 15:00:46 GMT"
}
] | 2010-04-12T00:00:00 | [
[
"The BABAR Collaboration",
"",
""
],
[
"Aubert",
"B.",
""
]
] |
0704.2081 | Jean Cortissoz | Jean Cortissoz | Three-manifolds of positive Ricci curvature and convex weakly umbilic
boundary | 14 pages | null | null | null | math.DG | null | In this paper we consider three-manifolds with weakly umbilic boundary (the
Second Fundamental form of the boundary is a constant multiple of the metric).
We show that if the initial manifold has positive Ricci curvature and the
boundary is convex (nonnegative Second Fundamental form), its metric can be
deformed via the Ricci flow to a metric of constant curvature and totally
geodesic boundary.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 00:14:33 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Cortissoz",
"Jean",
""
]
] |
0704.2082 | Yuki Sato | Yuki Sato, Aditya Joshi, and Richard Packard | Direct measurement of quantum phase gradients in superfluid 4He flow | null | null | 10.1103/PhysRevLett.98.195302 | null | cond-mat.supr-con | null | We report a new kind of experiment in which we generate a known superfluid
velocity in a straight tube and directly determine the phase difference across
the tube's ends using a superfluid matter wave interferometer. By so doing, we
quantitatively verify the relation between the superfluid velocity and the
phase gradient of the condensate macroscopic wave function. Within the
systematic error of the measurement (~10%) we find v_s=(hbar/m_4)*(grad phi).
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 00:51:01 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sato",
"Yuki",
""
],
[
"Joshi",
"Aditya",
""
],
[
"Packard",
"Richard",
""
]
] |
0704.2083 | Hassan Satori | H. Satori, M. Harti and N. Chenfour | Introduction to Arabic Speech Recognition Using CMUSphinx System | 4 pages, 3 figures and 2 tables, was in Information and Communication
Technologies International Symposium proceeding ICTIS07 Fes (2007) | null | null | null | cs.CL cs.AI | null | In this paper Arabic was investigated from the speech recognition problem
point of view. We propose a novel approach to build an Arabic Automated Speech
Recognition System (ASR). This system is based on the open source CMU Sphinx-4,
from the Carnegie Mellon University. CMU Sphinx is a large-vocabulary;
speaker-independent, continuous speech recognition system based on discrete
Hidden Markov Models (HMMs). We build a model using utilities from the
OpenSource CMU Sphinx. We will demonstrate the possible adaptability of this
system to Arabic voice recognition.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 01:04:01 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Satori",
"H.",
""
],
[
"Harti",
"M.",
""
],
[
"Chenfour",
"N.",
""
]
] |
0704.2084 | Neepa Maitra | Neepa T. Maitra and Kieron Burke | Comment on ``Analysis of Floquet formulation of time-dependent
density-functional theory'' [Chem. Phys. Lett. {\bf 433} (2006), 204] | Will appear as a Comment in CPL, on the paper cited above that is
also available at arXiv:cond-mat/0611428 | null | null | null | cond-mat.mtrl-sci | null | We discuss the relationship between modern time-dependent density functional
theory and earlier time-periodic versions, and why the criticisms in a recent
paper (Chem. Phys. Lett. {\bf 433} (2006) 204) of our earlier analysis (Chem.
Phys. Lett. {\bf 359} (2002) 237) are incorrect.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 01:13:32 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Maitra",
"Neepa T.",
""
],
[
"Burke",
"Kieron",
""
]
] |
0704.2085 | Y. M. Pihlstr\"om | Y.M. Pihlstr\"om (1), G.B. Taylor (1), J. Granot (2), S. Doeleman (3)
((1) University of New Mexico, (2) Kavli Institute of Particle Astrophysics
and Cosmology, (3) MIT Haystack Observatory) | Stirring the Embers: High Sensitivity VLBI Observations of GRB030329 | 16 pages, 5 figures, accepted for publication in Astrophysical
Journal | Astrophys.J.664:411-415,2007 | 10.1086/518955 | null | astro-ph | null | We present high sensitivity Very Long Baseline Interferometry (VLBI)
observations 806 days after the gamma-ray burst of 2003 March 29 (GRB030329).
The angular diameter of the radio afterglow is measured to be 0.347 +- 0.09
mas, corresponding to 0.99 +- 0.26 pc at the redshift of GRB030329 (z =
0.1685). The evolution of the image size favors a uniform external density over
an R^-2 wind-like density profile (at distances of R >~10^18 cm from the
source), although the latter cannot be ruled out yet. The current apparent
expansion velocity of the image size is only mildly relativistic, suggesting a
non-relativistic transition time of t_NR ~ 1 yr. A rebrightening, or at least a
significant flattening in the flux decay, is expected within the next several
years as the counter-jet becomes visible (this has not yet been observed). An
upper limit of <1.9c is set on the proper motion of the flux centroid.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 01:38:32 GMT"
}
] | 2010-11-11T00:00:00 | [
[
"Pihlström",
"Y. M.",
""
],
[
"Taylor",
"G. B.",
""
],
[
"Granot",
"J.",
""
],
[
"Doeleman",
"S.",
""
]
] |
0704.2086 | Hyerim Noh | J. Hwang and H. Noh | Third-order cosmological perturbations of zero-pressure multi-component
fluids: Pure general relativistic nonlinear effects | 20 pages, no figure | JCAP 0712:003,2007 | 10.1088/1475-7516/2007/12/003 | null | astro-ph | null | Present expansion stage of the universe is believed to be mainly governed by
the cosmological constant, collisionless dark matter and baryonic matter. The
latter two components are often modeled as zero-pressure fluids. In our
previous work we have shown that to the second-order cosmological
perturbations, the relativistic equations of the zero-pressure, irrotational,
multi-component fluids in a spatially near flat background effectively coincide
with the Newtonian equations. As the Newtonian equations only have quadratic
order nonlinearity, it is practically interesting to derive the potential
third-order perturbation terms in general relativistic treatment which
correspond to pure general relativistic corrections. Here, we present pure
general relativistic correction terms appearing in the third-order
perturbations of the multi-component zero-pressure fluids. We show that, as in
a single component situation, the third-order correction terms are quite small
(~ 5 x10^{-5} smaller compared with the relativistic/Newtonian second-order
terms) due to the weak level anisotropy of the cosmic microwave background
radiation. Still, there do exist pure general relativistic correction terms in
third-order perturbations which could potentially become important in future
development of precision cosmology. We include the cosmological constant in all
our analyses.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 01:40:18 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Hwang",
"J.",
""
],
[
"Noh",
"H.",
""
]
] |
0704.2087 | Dafa Li | D. Li, X. Li, H. Huang, X. Li | The SLOCC invariant and the residual entanglement for n-qubits | 22 pages, no figure, lemma 4 and corollary 3 and the conjecture for
odd n-qubits in the previous version were deleted because they are not always
true | PRA 76, 032304 (2007) | 10.1103/PhysRevA.76.032304 | null | quant-ph | null | In this paper, we find the invariant for $n$-qubits and propose the residual
entanglement for $n$-qubits by means of the invariant. Thus, we establish a
relation between SLOCC entanglement and the residual entanglement. The
invariant and the residual entanglement can be used for SLOCC entanglement
classification for $n$-qubits.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 02:02:12 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Sep 2007 09:34:28 GMT"
}
] | 2012-05-07T00:00:00 | [
[
"Li",
"D.",
""
],
[
"Li",
"X.",
""
],
[
"Huang",
"H.",
""
],
[
"Li",
"X.",
""
]
] |
0704.2088 | Shimul Akhanjee | Shimul Akhanjee | Exact longitudinal plasmon dispersion relations for one and two
dimensional Wigner crystals | 4 pages, 1 figure. Important typos and errors fixed, 2D dispersion
added | Phys. Rev. B 76, 165129 (2007) | 10.1103/PhysRevB.76.165129 | null | cond-mat.str-el | null | We derive the exact longitudinal plasmon dispersion relations, $\omega(k)$ of
classical one and two dimensional Wigner crystals at T=0 from the real space
equations of motion, of which properly accounts for the full unscreened Coulomb
interactions. We make use of the polylogarithm function in order to evaluate
the infinite lattice sums of the electrostatic force constants. From our exact
results we recover the correct long-wavelength behavior of previous approximate
methods. In 1D, $\omega(k) \sim | k |\log ^{1/2} (1/k)$, validating the known
RPA and bosonization form. In 2D $\omega(k) \sim \sqrt k$, agreeing remarkably
with the celebrated Ewald summation result. Additionally, we extend this
analysis to calculate the band structure of tight-binding models of
non-interacting electrons with arbitrary power law hopping.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 02:39:42 GMT"
},
{
"version": "v2",
"created": "Tue, 8 May 2007 08:33:09 GMT"
},
{
"version": "v3",
"created": "Sat, 12 May 2007 04:14:59 GMT"
}
] | 2011-11-09T00:00:00 | [
[
"Akhanjee",
"Shimul",
""
]
] |
0704.2089 | Roman Shvydkoy | A. Cheskidov, S. Friedlander, R. Shvydkoy | On the energy equality for weak solutions of the 3D Navier-Stokes
equations | 7 pages | null | null | null | math.AP math-ph math.MP | null | We prove that the energy equality holds for weak solutions of the 3D
Navier-Stokes equations in the functional class $L^3([0,T);V^{5/6})$, where
$V^{5/6}$ is the domain of the fractional power of the Stokes operator
$A^{5/12}$.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 02:20:50 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Cheskidov",
"A.",
""
],
[
"Friedlander",
"S.",
""
],
[
"Shvydkoy",
"R.",
""
]
] |
0704.2090 | Roman Shvydkoy | R. Shvydkoy | Cocycles and Ma\~{n}e sequences with an application to ideal fluids | 14 pages | Journal of Differential Equations, 229/1 (2006), 49--62 | null | null | math.DS math.AP | null | Exponential dichotomy of a strongly continuous cocycle $\bFi$ is proved to be
equivalent to existence of a Ma\~{n}e sequence either for $\bFi$ or for its
adjoint. As a consequence we extend some of the classical results to general
Banach bundles. The dynamical spectrum of a product of two cocycles, one of
which is scalar, is investigated and applied to describe the essential spectrum
of the Euler equation in an arbitrary spacial dimension.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 02:30:26 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Shvydkoy",
"R.",
""
]
] |
0704.2091 | Ping Dong | Ping Dong, Ming Yang and Zhuo-Liang Cao | Discrete quantum Fourier transform in coupled semiconductor double
quantum dot molecules | 3 pages,2 figures | Physics Letters A 373 (2008) 30-32 | 10.1016/j.physleta.2008.11.005 | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this Letter, we present a physical scheme for implementing the discrete
quantum Fourier transform in a coupled semiconductor double quantum dot system.
The main controlled-R gate operation can be decomposed into many simple and
feasible unitary transformations. The current scheme would be a useful step
towards the realization of complex quantum algorithms in the quantum dot
system.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 02:59:24 GMT"
},
{
"version": "v2",
"created": "Fri, 28 Nov 2008 08:00:44 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dong",
"Ping",
""
],
[
"Yang",
"Ming",
""
],
[
"Cao",
"Zhuo-Liang",
""
]
] |
0704.2092 | Jinsong Tan | Jinsong Tan | A Note on the Inapproximability of Correlation Clustering | null | Information Processing Letters, 108: 331-335, 2008 | null | null | cs.LG cs.DS | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider inapproximability of the correlation clustering problem defined
as follows: Given a graph $G = (V,E)$ where each edge is labeled either "+"
(similar) or "-" (dissimilar), correlation clustering seeks to partition the
vertices into clusters so that the number of pairs correctly (resp.
incorrectly) classified with respect to the labels is maximized (resp.
minimized). The two complementary problems are called MaxAgree and MinDisagree,
respectively, and have been studied on complete graphs, where every edge is
labeled, and general graphs, where some edge might not have been labeled.
Natural edge-weighted versions of both problems have been studied as well. Let
S-MaxAgree denote the weighted problem where all weights are taken from set S,
we show that S-MaxAgree with weights bounded by $O(|V|^{1/2-\delta})$
essentially belongs to the same hardness class in the following sense: if there
is a polynomial time algorithm that approximates S-MaxAgree within a factor of
$\lambda = O(\log{|V|})$ with high probability, then for any choice of S',
S'-MaxAgree can be approximated in polynomial time within a factor of $(\lambda
+ \epsilon)$, where $\epsilon > 0$ can be arbitrarily small, with high
probability. A similar statement also holds for $S-MinDisagree. This result
implies it is hard (assuming $NP \neq RP$) to approximate unweighted MaxAgree
within a factor of $80/79-\epsilon$, improving upon a previous known factor of
$116/115-\epsilon$ by Charikar et. al. \cite{Chari05}.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 03:52:41 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Mar 2009 03:22:02 GMT"
}
] | 2009-03-23T00:00:00 | [
[
"Tan",
"Jinsong",
""
]
] |
0704.2093 | Hiroyuki Nishiura | Masaru Doi, Tsuneyuki Kotani, Hiroyuki Nishiura | New Parameterization in Muon Decay and the Type of Emitted Neutrino. II | 21 pages | Prog.Theor.Phys.118:1069-1086, 2007; Erratum-ibid.122:805-805,2009 | 10.1143/PTP.118.1069 10.1143/PTP.122.805 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In a previous paper, new sets of parameters to replace the Michel parameters
were proposed to analyze data for the muon decay $\mu^{+} \to
e^{+}\nu_{e}\bar{\nu_{\mu}}$. Both $(V-A)$ and $(V+A)$ charged currents with
finite neutrino mass have been used to study this decay. In the present paper,
this parameterization is extended to a more general form, and a method for data
analysis (least squares) is discussed for the propose of determining the rate
of contribution from the $(V+A)$ current. We find that there is a simple form
in which the set of parameters is related primitively to the physical
quantities. It is shown that the Michel parameters are one of the other sets
that are obtained from this simple form by rearranging one term. We derive the
condition to obtain the same information regarding unknown physical quantities
in the case that the data are analyzed using these simple and rearranged forms
separately. We find that there is some possibility to get different results
from these analyses, because the equivalent condition is very delicate and the
QED radiative corrections should be treated carefully. We propose a consistent
formula for data analysis. It is useful to compare the value obtained in the
least squares fit using the simple form with that obtained using the prediction
of the standard model, because a large difference is not expected, especially
in the case of the Majorana neutrino. Finally, we point out that the method we
proposed to determine the type of neutrino in the previous paper is incorrect.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 03:18:20 GMT"
},
{
"version": "v2",
"created": "Sun, 18 Nov 2007 01:45:36 GMT"
},
{
"version": "v3",
"created": "Sun, 9 Dec 2007 09:14:55 GMT"
},
{
"version": "v4",
"created": "Fri, 2 Oct 2009 00:49:57 GMT"
}
] | 2010-01-07T00:00:00 | [
[
"Doi",
"Masaru",
""
],
[
"Kotani",
"Tsuneyuki",
""
],
[
"Nishiura",
"Hiroyuki",
""
]
] |
0704.2094 | Haipeng Liu | Ming-Jun Lai, and Haipeng Liu | Prewavelet Solution to Poisson Equations | null | null | null | null | math.NA | null | Finite element method is one of powerful numerical methods to solve PDE.
Usually, if a finite element solution to a Poisson equation based on a
triangulation of the underlying domain is not accurate enough, one will discard
the solution and then refine the triangulation uniformly and compute a new
finite element solution over the refined triangulation. It is wasteful to
discard the original finite element solution. We propose a prewavelet method to
save the original solution by adding a prewavelet subsolution to obtain the
refined level finite element solution. To increase the accuracy of numerical
solution to Poisson equations, we can keep adding prewavelet subsolutions.
Our prewavelets are orthogonal in the $H^1$ norm and they are compactly
supported except for one globally supported basis function in a rectangular
domain. We have implemented these prewavelet basis functions in MATLAB and used
them for numerical solution of Poisson equation with Dirichlet boundary
conditions. Numerical simulation demonstrates that our prewavelet solution is
much more efficient than the standard finite element method.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 03:26:31 GMT"
}
] | 2007-05-23T00:00:00 | [
[
"Lai",
"Ming-Jun",
""
],
[
"Liu",
"Haipeng",
""
]
] |
0704.2095 | I-chin Wang | I-Chin Wang and Kin-Wang Ng | Effects of a pre-inflation radiation-dominated epoch to CMB anisotropy | paper revised,a new figure is added and new references added | Phys.Rev.D77:083501,2008 | 10.1103/PhysRevD.77.083501 | null | astro-ph | null | We consider that the pre-inflation era is radiation-dominated, transiting
smoothly to the inflationary era. We work out in detail the dynamics of
inflaton fluctuations across the phase transition and the proper choices of
initial vacuum states. It is found that this phase transition can suppress
long-wavelength quantum fluctuations of inflaton. This may attribute to the
large-scale CMB anisotropy a lower power than predicted in the standard
$\Lambda$CDM model. In constraining this transitional effect by WMAP anisotropy
data, we use the WMAP best-fit scale-invariant $\Lambda$CDM model with the
density power spectrum replaced by the one found in this work. We find that the
transition occurs at least about 10 e-folds before the comoving scales
comparable to our present horizon size cross the Hubble radius during
inflation.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 04:00:28 GMT"
},
{
"version": "v2",
"created": "Tue, 16 Oct 2007 16:54:20 GMT"
},
{
"version": "v3",
"created": "Wed, 20 Feb 2008 07:20:39 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Wang",
"I-Chin",
""
],
[
"Ng",
"Kin-Wang",
""
]
] |
0704.2096 | Steven Longmore N | S. N. Longmore (1 and 2), M. G. Burton (1), P. J. Barnes (3 and 1), T.
Wong (1 and 2 and 5), C. R. Purcell (1 and 4), J. Ott (2 and 6) ((1) UNSW,
(2) ATNF, (3) Uni. of Sydney, (4) Jodrell Bank Observatory, (5) Uni. of
Illinois, (6) NRAO) | Multi-wavelength observations of Southern Hot Molecular Cores traced by
methanol masers - I. Ammonia and 24 GHz Continuum Data | 25 pages, 14 figures, accepted MNRAS. Shortened versions of Figures
13 and 14 | Mon.Not.Roy.Astron.Soc.379:535-572,2007 | 10.1111/j.1365-2966.2007.11850.x | null | astro-ph | null | We present observations of the (1,1), (2,2), (4,4) and (5,5) inversion
transitions of para-ammonia (NH3) and 24 GHz continuum, taken with the
Australia Telescope Compact Array toward 21 southern Galactic hot molecular
cores traced by 6.7 GHz methanol maser emission. We detect NH3(1,1) emission
toward all 21 regions and 24 GHz continuum emission toward 12 of the regions,
including 6 with no reported 8 GHz continuum counterparts. In total, we find
the 21 regions contain 41 NH3(1,1) cores. We extract characteristic spectra for
every core at each of the NH3 transitions and present both integrated intensity
maps and channel maps for each region. The NH3(4,4)+(5,5) emission is always
unresolved and found at the maser position indicating that the methanol masers
are found at the warmest part of the core. We observe large asymmetries in the
NH3(1,1) hyperfine line profiles and conclude this is due to a number of dense,
small clumps within the beam. We derive properties of the ionised gas and find
the 24 GHz continuum sources not detected at 8 GHz are always coincident with
both NH3 and methanol masers in contrast to those detected at 8 + 24 GHz which
are generally offset from the methanol masers. We investigate the possibility
that the former may be hyper-compact HII regions. Finally, we separate the
cores into five groups, based on their association with NH3, methanol maser and
continuum emission. From the different physical properties of the cores in the
groups, we discuss the possibility that these groups may represent cores at
different evolutionary stages of the massive star formation process.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 04:12:01 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Longmore",
"S. N.",
"",
"1 and 2"
],
[
"Burton",
"M. G.",
"",
"3 and 1"
],
[
"Barnes",
"P. J.",
"",
"3 and 1"
],
[
"Wong",
"T.",
"",
"1 and 2 and 5"
],
[
"Purcell",
"C. R.",
"",
"1 and 4"
],
[
"Ott",
"J.",
"",
"2 and 6"
]
] |
0704.2097 | Stuart Wilson | S.D.Wilson, A.R.R.Carvalho, J.J.Hope and M.R.James | Effects of Measurement back-action in the stabilization of a
Bose-Einstein condensate through feedback | 1 Tex, 4 PS pictures, 1 bbl file | null | 10.1103/PhysRevA.76.013610 | null | quant-ph | null | We apply quantum filtering and control to a particle in a harmonic trap under
continuous position measurement, and show that a simple static feedback law can
be used to cool the system. The final steady state is Gaussian and dependent on
the feedback strength and coupling between the system and probe. In the limit
of weak coupling this final state becomes the ground state. An earlier model by
Haine et. al. (PRA 69, 2004) without measurement back-action showed dark
states: states that did not display error signals, thus remaining unaffected by
the control. This paper shows that for a realistic measurement process this is
not true, which indicates that a Bose-Einstein condensate may be driven towards
the ground state from any arbitrary initial state.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 05:08:46 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wilson",
"S. D.",
""
],
[
"Carvalho",
"A. R. R.",
""
],
[
"Hope",
"J. J.",
""
],
[
"James",
"M. R.",
""
]
] |
0704.2098 | Robert Parviainen | Robert Parviainen | Estimation of Bond Percolation Thresholds on the Archimedean Lattices | 2 figures. Updated Table 1 | J. Phys. A: Math. Theor. 40 (31), 9253-9258, 2007 | 10.1088/1751-8113/40/31/005 | null | cond-mat.stat-mech | null | We give accurate estimates for the bond percolation critical probabilities on
seven Archimedean lattices, for which the critical probabilities are unknown,
using an algorithm of Newman and Ziff.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 05:40:57 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Apr 2007 00:10:59 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Parviainen",
"Robert",
""
]
] |
0704.2099 | Muhammad Sharif | M. Sharif and M. Jamil Amir | Teleparallel Energy-Momentum Distribution of Static Axially Symmetric
Spacetimes | 14 pages, accepted for publication in Mod. Phys. Lett. A | Mod.Phys.Lett.A23:3167-3177,2008 | 10.1142/S0217732308027035 | null | gr-qc | null | This paper is devoted to discuss the energy-momentum for static axially
symmetric spacetimes in the framework of teleparallel theory of gravity. For
this purpose, we use the teleparallel versions of Einstein, Landau-Lifshitz,
Bergmann and M$\ddot{o}$ller prescriptions. A comparison of the results shows
that the energy density is different but the momentum turns out to be constant
in each prescription. This is exactly similar to the results available in
literature using the framework of General Relativity. It is mentioned here that
M$\ddot{o}$ller energy-momentum distribution is independent of the coupling
constant $\lambda$. Finally, we calculate energy-momentum distribution for the
Curzon metric, a special case of the above mentioned spacetime.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 05:43:49 GMT"
}
] | 2009-02-10T00:00:00 | [
[
"Sharif",
"M.",
""
],
[
"Amir",
"M. Jamil",
""
]
] |
0704.2100 | Alessandro Capetti | Alessandro Capetti (1) Barbara Balmaverde (1) ((1)INAF - Osservatorio
Astronomico di Torino, Italy) | The host galaxy/AGN connection. Brightness profiles of early-type
galaxies hosting Seyfert nuclei | Accepted for publication in A&A | null | 10.1051/0004-6361:20066684 | null | astro-ph | null | [ABRIDGED] We recently presented evidence of a connection between the
brightness profiles of nearby early-type galaxies and the properties of the AGN
they host. The radio loudness of the AGN appears to be univocally related to
the host's brightness profile: radio-loud nuclei are only hosted by ``core''
galaxies while radio-quiet AGN are only found in ``power-law'' galaxies. We
extend our analysis here to a sample of 42 nearby (V < 7000 km/s) Seyfert
galaxies hosted by early-type galaxies. We used the available HST images to
study their brightness profiles. Having excluded complex and highly nucleated
galaxies, in the remaining 16 objects the brightness profiles can be
successfully modeled with a Nuker law with a steep nuclear cusp characteristic
of ``power-law'' galaxies (with logarithmic slope 0.51 - 1.07). This result is
what is expected for these radio-quiet AGN based on our previous findings, thus
extending the validity of the connection between brightness profile and radio
loudness to AGN of a far higher luminosity. We explored the robustness of this
result against a different choice of the analytic form for the brightness
profiles, using a Sersic law. In no object could we find evidence of a central
light deficit with respect to a pure Sersic model, the defining feature of
``core'' galaxies in this modeling framework. We conclude that, regardless of
the modeling strategy, the dichotomy of AGN radio loudness can be univocally
related to the host's brightness profile. Our general results can be re-phrased
as ``radio-loud nuclei are hosted by core galaxies, while radio-quiet AGN are
found in non-core galaxies''.
| [
{
"version": "v1",
"created": "Tue, 17 Apr 2007 06:01:32 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Capetti",
"Alessandro",
""
],
[
"Balmaverde",
"Barbara",
""
]
] |
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