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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.1914 | Ali Mohammad-Djafari | Ali Mohammad-Djafari | Approche variationnelle pour le calcul bay\'esien dans les probl\`emes
inverses en imagerie | 4 pages, 1 figure, accepted for GRETSI 2007
(http://www.gretsi2007.org), Troys, France | null | null | null | physics.data-an physics.comp-ph | null | In a non supervised Bayesian estimation approach for inverse problems in
imaging systems, one tries to estimate jointly the unknown image pixels $\fb$
and the hyperparameters $\thetab$. This is, in general, done through the joint
posterior law $p(\fb,\thetab|\gb)$. The expression of this joint law is often
very complex and its exploration through sampling and computation of the point
estimators such as MAP and posterior means need either optimization of non
convex criteria or int\'egration of non Gaussian and multi variate probability
laws. In any of these cases, we need to do approximations. We had explored
before the possibilities of Laplace approximation and sampling by MCMC. In this
paper, we explore the possibility of approximating this joint law by a
separable one in $\fb$ and in $\thetab$. This gives the possibility of
developing iterative algorithms with more reasonable computational cost, in
particular, if the approximating laws are choosed in the exponential conjugate
families. The main objective of this paper is to give details of different
algorithms we obtain with different choices of these families.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 14:36:58 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Mohammad-Djafari",
"Ali",
""
]
] |
0706.1915 | Mat\'ias Gra\~na | Matias Gra\~na, Jorge A. Guccione, Juan J. Guccione | How to disentangle two braided Hopf algebras | 4 pages | null | null | null | math.QA | null | We show how to define the tensor product of two braided Hopf algebras.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:01:09 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Graña",
"Matias",
""
],
[
"Guccione",
"Jorge A.",
""
],
[
"Guccione",
"Juan J.",
""
]
] |
0706.1916 | Philip E. Hardee | Philip Hardee, Yosuke Mizuno and Ken-Ichi Nishikawa | GRMHD/RMHD Simulations and Stability of Magnetized Spine-Sheath
Relativistic Jets | 5 pages, 5 figures, accepted for publication in Astrophysics and
Space Science | Astrophys.Space Sci.311:281-286,2007 | 10.1007/s10509-007-9529-1 | null | astro-ph | null | A new general relativistic magnetohydrodynamics (GRMHD) code ``RAISHIN'' used
to simulate jet generation by rotating and non-rotating black holes with a
geometrically thin Keplarian accretion disk finds that the jet develops a
spine-sheath structure in the rotating black hole case. Spine-sheath structure
and strong magnetic fields significantly modify the Kelvin-Helmholtz (KH)
velocity shear driven instability. The RAISHIN code has been used in its
relativistic magnetohydrodynamic (RMHD) configuration to study the effects of
strong magnetic fields and weakly relativistic sheath motion, c/2, on the KH
instability associated with a relativistic, Lorentz factor equal 2.5, jet
spine-sheath interaction. In the simulations sound speeds up to c/1.7 and
Alfven wave speeds up to 0.56 c are considered. Numerical simulation results
are compared to theoretical predictions from a new normal mode analysis of the
RMHD equations. Increased stability of a weakly magnetized system resulting
from c/2 sheath speeds and stabilization of a strongly magnetized system
resulting from c/2 sheath speeds is found.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 14:44:09 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Hardee",
"Philip",
""
],
[
"Mizuno",
"Yosuke",
""
],
[
"Nishikawa",
"Ken-Ichi",
""
]
] |
0706.1917 | Liu Quanxing | Fen-Ni Si, Quan-Xing Liu, Jin-Zhong Zhang and Lu-Qun Zhou | Propagation of travelling waves in sub-excitable systems driven by noise
and periodic forcing | Some references and information are added in the modified version.
Accepted, The European Physical Journal B | Eur. Phys. J. B 60, 507-513 (2007) | 10.1140/epjb/e2008-00009-1 | null | nlin.CD nlin.PS physics.flu-dyn physics.med-ph | null | It has been reported that traveling waves propagate periodically and stably
in sub-excitable systems driven by noise [Phys. Rev. Lett. \textbf{88}, 138301
(2002)]. As a further investigation, here we observe different types of
traveling waves under different noises and periodic forces, using a simplified
Oregonator model. Depending on different noises and periodic forces, we have
observed different types of wave propagation (or their disappearance).
Moreover, the reversal phenomena are observed in this system based on the
numerical experiments in the one-dimensional space. As an explanation, we
regard it as the effect of periodic forces. Thus, we give qualitative
explanations to how reversal phenomena stably appear, which seem to arise from
the mixing function of the periodic force and the noise. And the output period
and three velocities (the normal, the positive and the negative) of the
travelling waves are defined and their relationship with the periodic forces,
along with the types of waves, are also studied in sub-excitable system under a
fixed noise intensity.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 14:44:54 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Jul 2007 00:32:35 GMT"
},
{
"version": "v3",
"created": "Fri, 23 Nov 2007 09:49:05 GMT"
}
] | 2008-01-17T00:00:00 | [
[
"Si",
"Fen-Ni",
""
],
[
"Liu",
"Quan-Xing",
""
],
[
"Zhang",
"Jin-Zhong",
""
],
[
"Zhou",
"Lu-Qun",
""
]
] |
0706.1918 | Michael Joswig | Michael Joswig, Bernd Sturmfels, and Josephine Yu | Affine Buildings and Tropical Convexity | 22 pages, 4 figures | Albanian J. Math. 1 (2007), no. 4, 187--211 | null | null | math.MG math.CO | null | The notion of convexity in tropical geometry is closely related to notions of
convexity in the theory of affine buildings. We explore this relationship from
a combinatorial and computational perspective. Our results include a convex
hull algorithm for the Bruhat--Tits building of SL$_d(K)$ and techniques for
computing with apartments and membranes. While the original inspiration was the
work of Dress and Terhalle in phylogenetics, and of Faltings, Kapranov, Keel
and Tevelev in algebraic geometry, our tropical algorithms will also be
applicable to problems in other fields of mathematics.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 14:49:57 GMT"
}
] | 2012-02-13T00:00:00 | [
[
"Joswig",
"Michael",
""
],
[
"Sturmfels",
"Bernd",
""
],
[
"Yu",
"Josephine",
""
]
] |
0706.1919 | J. M. Pitarke | Lucian A. Constantin and J. M. Pitarke | Simple dynamic exchange-correlation kernel of the uniform electron gas | 6 pages, 8 figures, to appear in Phys. Rev. B | null | 10.1103/PhysRevB.75.245127 | null | cond-mat.mtrl-sci | null | We propose a simple dynamic exchange-correlation kernel of the uniform
electron gas. We model the reduction of the electron-electron interaction due
to short-range exchange-correlation effects by introducing a
frequency-dependent error-function effective interaction. By imposing the
fulfillment of the compresibility and the third-frequency-moment sum rules, as
well as the correct asymptotic behavior at large wave vectors, we find an
accurate and simple dynamic exchange-correlation kernel that accurately
reproduces the wave-vector analysis and the imaginary-frequency analysis of the
correlation energy of the uniform electron gas.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 14:52:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Constantin",
"Lucian A.",
""
],
[
"Pitarke",
"J. M.",
""
]
] |
0706.1920 | Jacob Fox | Jacob Fox and Benny Sudakov | On a problem of Duke-Erdos-Rodl on cycle-connected subgraphs | 7 pages | null | null | null | math.CO math.NT | null | In this short note, we prove that for \beta < 1/5 every graph G with n
vertices and n^{2-\beta} edges contains a subgraph G' with at least
cn^{2-2\beta} edges such that every pair of edges in G' lie together on a cycle
of length at most 8. Moreover edges in G' which share a vertex lie together on
a cycle of length at most 6. This result is best possible up to the constant
factor and settles a conjecture of Duke, Erdos, and Rodl.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:09:03 GMT"
},
{
"version": "v2",
"created": "Fri, 17 Aug 2007 23:18:20 GMT"
},
{
"version": "v3",
"created": "Sun, 11 Nov 2007 22:29:26 GMT"
}
] | 2007-11-12T00:00:00 | [
[
"Fox",
"Jacob",
""
],
[
"Sudakov",
"Benny",
""
]
] |
0706.1921 | Ralph Engel | Ralph Engel (for the Pierre Auger Collaboration) | Test of hadronic interaction models with data from the Pierre Auger
Observatory | Contribution to the 30th International Cosmic Ray Conference, Merida,
Mexico, July 2007 | null | null | null | astro-ph | null | The Pierre Auger Observatory allows the measurement of both longitudinal
profiles and lateral particle distributions of high-energy showers. The former
trace the overall shower development, mainly of the electromagnetic component
close to the core where the latter reflect the particle densities in the tail
of the shower far away from the core and are sensitive to both the muonic and
electromagnetic components. Combining the two complementary measurements,
predictions of air shower simulations are tested. In particular the muon
component of the tank signals, which is sensitive to hadronic interactions at
high energy, is studied with several independent methods. Implications for the
simulation of hadronic interactions at ultra-high energy are discussed.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:04:46 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Engel",
"Ralph",
"",
"for the Pierre Auger Collaboration"
]
] |
0706.1922 | Jasper van Wezel | Jasper van Wezel and Jeroen van den Brink | Spontaneous Symmetry Breaking and Decoherence in Superconductors | 11 pages, 4 figures; corrected typos | Phys. Rev. B, 77, 064523 (2008) | 10.1103/PhysRevB.77.064523 | null | cond-mat.supr-con | null | We show that superconductors have a thin spectrum associated with spontaneous
symmetry breaking similar to that of antiferromagnets, while still being in
full agreement with Elitzur's theorem, which forbids the spontaneous breaking
of local (gauge) symmetries. This thin spectrum in the superconductors consists
of in-gap states that are associated with the spontaneous breaking of a global
phase symmetry. In qubits based on mesoscopic superconducting devices, the
presence of the thin spectrum implies a maximum coherence time which is
proportional to the number of Cooper pairs in the device. Here we present the
detailed calculations leading up to these results and discuss the relation
between spontaneous symmetry breaking in superconductors and the Meissner
effect, the Anderson-Higgs mechanism and the Josephson effect. Whereas for the
Meissner effect a symmetry breaking of the phase of the superconductor is not
required, it is essential for the Josephson effect.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:05:22 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 07:54:21 GMT"
}
] | 2010-04-29T00:00:00 | [
[
"van Wezel",
"Jasper",
""
],
[
"Brink",
"Jeroen van den",
""
]
] |
0706.1923 | Abouzeid Shalaby Dr. | Abouzeid M. Shalaby | A Novel phase in the phase structure of the $(g\phi^4 + h\phi^6)_{1+1}$
field theoretic model | 13 pages, 4 figures | Phys.Rev.D76:041702,2007 | 10.1103/PhysRevD.76.041702 | null | hep-th | null | In view of the newly discovered and physically acceptable $PT$ symmetric and
non-Hermitian models, we reinvestigated the phase structure of the
($g\phi^{4}+h\phi^{6}$)$_{1+1}$ Hermitian model. The reinvestigation concerns
the possibility of a phase transition from the original Hermitian and $PT$
symmetric phase to a non-Hermitian and $PT$ symmetric one. This kind of phase
transition, if verified experimentally, will lead to the first proof that
non-Hermitian and $PT$ symmetric models are not just a mathematical research
framework but are a nature desire. To do the investigation, we calculated the
effective potential up to second order in the couplings and found a Hermitian
to Non-Hermitian phase transition. This leads us to introduce, for the first
time, hermiticity as a symmetry which can be broken due to quantum corrections,
\textit{i.e.}, when starting with a model which is Hermitian in the classical
level, quantum corrections can break hermiticity while the theory stays
physically acceptable. In fact, ignoring this phase will lead to violation of
universality when comparing this model predictions with other models in the
same class of universality. For instance, in a previous work we obtained a
second order phase transition for the $PT$ symmetric and non-Hermitian
$(-g\phi^{4})$ and according to universality, this phase should exist in the
phase structure of the ($g\phi^{4}+h\phi^{6}$) model for negative $g$. Finally,
among the novelties in this letter, in our calculation for the effective
potential, we introduced a new renormalization group equation which describes
the invariance of the bare vacuum energy under the change of the scale. We
showed that without this invariance, the original theory and the effective one
are inequivalent.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:13:31 GMT"
},
{
"version": "v2",
"created": "Thu, 14 Jun 2007 12:45:08 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Shalaby",
"Abouzeid M.",
""
]
] |
0706.1924 | Nicolas Sangouard | Nicolas Sangouard, Christoph Simon, Jiri Minar, Hugo Zbinden, Hugues
de Riedmatten, and Nicolas Gisin | Long-Distance Entanglement Distribution with Single-Photon Sources | 4 pages, 1 figure, 1 table | Phys. Rev. A 76, 050301(R) (2007) | 10.1103/PhysRevA.76.050301 | null | quant-ph | null | We present an efficient architecture for quantum repeaters based on
single-photon sources in combination with quantum memories for photons. Errors
inherent to previous repeater protocols using photon-pair sources are
eliminated, leading to a significant gain in efficiency. We establish the
requirements on the single-photon sources and on the photon detectors.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:13:39 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sangouard",
"Nicolas",
""
],
[
"Simon",
"Christoph",
""
],
[
"Minar",
"Jiri",
""
],
[
"Zbinden",
"Hugo",
""
],
[
"de Riedmatten",
"Hugues",
""
],
[
"Gisin",
"Nicolas",
""
]
] |
0706.1925 | Xin Tao | Xin Tao, Anthony Chan, Alain Brizard | Hamiltonian Theory of Adiabatic Motion of Relativistic Charged Particles | 20 pages, LaTeX, to appear in Physics of Plasmas (Aug, 2007) | null | 10.1063/1.2773702 | null | physics.plasm-ph physics.space-ph | null | A general Hamiltonian theory for the adiabatic motion of relativistic charged
particles confined by slowly-varying background electromagnetic fields is
presented based on a unified Lie-transform perturbation analysis in extended
phase space (which includes energy and time as independent coordinates) for all
three adiabatic invariants. First, the guiding-center equations of motion for a
relativistic particle are derived from the particle Lagrangian. Covariant
aspects of the resulting relativistic guiding-center equations of motion are
discussed and contrasted with previous works. Next, the second and third
invariants for the bounce motion and drift motion, respectively, are obtained
by successively removing the bounce phase and the drift phase from the
guiding-center Lagrangian. First-order corrections to the second and third
adiabatic invariants for a relativistic particle are derived. These results
simplify and generalize previous works to all three adiabatic motions of
relativistic magnetically-trapped particles.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:13:54 GMT"
},
{
"version": "v2",
"created": "Tue, 31 Jul 2007 17:42:54 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Tao",
"Xin",
""
],
[
"Chan",
"Anthony",
""
],
[
"Brizard",
"Alain",
""
]
] |
0706.1926 | Michele Bezzi | Michele Bezzi, Robin Groenevelt | Towards understanding and modelling office daily life | 5 pages, ECHISE 2006 - 2nd International Workshop on Exploiting
Context Histories in Smart Environments - Infrastructures and Design, 8th
International Conference of Ubiquitous Computing (Ubicomp 2006), Orange
County, CA, 17-21 September 2006 | null | null | null | cs.CV cs.CY | null | Measuring and modeling human behavior is a very complex task. In this paper
we present our initial thoughts on modeling and automatic recognition of some
human activities in an office. We argue that to successfully model human
activities, we need to consider both individual behavior and group dynamics. To
demonstrate these theoretical approaches, we introduce an experimental system
for analyzing everyday activity in our office.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:15:00 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Bezzi",
"Michele",
""
],
[
"Groenevelt",
"Robin",
""
]
] |
0706.1927 | Eric Sedgwick | Yoav Moriah, Eric Sedgwick | The Heegaard structure of Dehn filled manifolds | This is the version published by Geometry & Topology Monographs on 3
December 2007 | Geom. Topol. Monogr. 12 (2007) 233-263 | 10.2140/gtm.2007.12.233 | null | math.GT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We expect manifolds obtained by Dehn filling to inherit properties from the
knot manifold. To what extent does that hold true for the Heegaard structure?
We study four changes to the Heegaard structure that may occur after filling:
(1) Heegaard genus decreases, (2) a new Heegaard surface is created, (3) a
non-stabilized Heegaard surface destabilizes, and (4) two or more non-isotopic
Heegaard surfaces become isotopic. We survey general results that give quite
satisfactory restrictions to phenomena (1) and (2) and, in a parallel thread,
give a complete classification of when all four phenomena occur when filling
most torus knot exteriors. This latter thread yields sufficient (and perhaps
necessary) conditions for the occurrence of phenomena (3) and (4).
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:22:29 GMT"
},
{
"version": "v2",
"created": "Tue, 31 Mar 2009 20:15:27 GMT"
}
] | 2009-03-31T00:00:00 | [
[
"Moriah",
"Yoav",
""
],
[
"Sedgwick",
"Eric",
""
]
] |
0706.1928 | Vassili Kolokoltsov | Vassili N. Kolokoltsov | Generalized Continuous-Time Random Walks (CTRW), Subordination by
Hitting Times and Fractional Dynamics | null | Theory of Probability and its Applications 53:4 (2009), 594-609 | 10.1137/S0040585X97983857 | null | math.PR math.AP | null | Functional limit theorem for continuous-time random walks (CTRW) are found in
general case of dependent waiting times and jump sizes that are also position
dependent. The limiting anomalous diffusion is described in terms of fractional
dynamics. Probabilistic interpretation of generalized fractional evolution is
given in terms of the random time change (subordination) by means of hitting
times processes.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:24:22 GMT"
}
] | 2022-05-03T00:00:00 | [
[
"Kolokoltsov",
"Vassili N.",
""
]
] |
0706.1929 | Jinzhu Han | Jinzhu Han | Proof of Riemann Hypothesis | null | null | null | null | math.GM | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this article, we will prove Riemann Hypothesis by using the mean value
theorem of integrals. The function $ \xi(s) $ is introduced by Riemann, which
zeros are identical equal to non-trivial zeros of zeta function.The function $
\xi(s) $ is an entire function, and its real part and imaginary part can be
represented as infinite integral form. In the special condition, the mean value
theorem of integrals is established for infinite integral. Using the mean value
theorem of integrals and the isolation of zeros of analytic function, we
determined that all zeros of the function $ \xi(s) $ have real part equal
to$\frac{1}{2}$, namely, all non-trivial zeros of zeta function lies on the
critical line. Riemann Hypothesis is true.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 16:21:17 GMT"
},
{
"version": "v10",
"created": "Wed, 29 Nov 2017 06:46:05 GMT"
},
{
"version": "v11",
"created": "Tue, 30 Oct 2018 02:56:17 GMT"
},
{
"version": "v12",
"created": "Sun, 10 Mar 2019 04:16:18 GMT"
},
{
"version": "v13",
"created": "Tue, 3 Sep 2019 05:43:31 GMT"
},
{
"version": "v2",
"created": "Thu, 11 Oct 2007 14:41:24 GMT"
},
{
"version": "v3",
"created": "Thu, 10 Jan 2008 00:14:45 GMT"
},
{
"version": "v4",
"created": "Sat, 12 Jan 2008 01:02:01 GMT"
},
{
"version": "v5",
"created": "Sat, 15 Mar 2008 01:34:48 GMT"
},
{
"version": "v6",
"created": "Sun, 11 May 2008 11:15:08 GMT"
},
{
"version": "v7",
"created": "Tue, 29 Mar 2011 06:09:20 GMT"
},
{
"version": "v8",
"created": "Mon, 12 Sep 2011 12:54:41 GMT"
},
{
"version": "v9",
"created": "Thu, 3 Nov 2016 14:31:13 GMT"
}
] | 2019-09-04T00:00:00 | [
[
"Han",
"Jinzhu",
""
]
] |
0706.1930 | Lorenzo Iorio | Lorenzo Iorio | LARES/WEBER-SAT and the equivalence principle | LaTex, 4 pages, no figures, no tables, 26 references. Proofs
corrections included. To appear in EPL (Europhysics Letters) | Europhys.Lett.80:40007,2007 | 10.1209/0295-5075/80/40007 | null | gr-qc astro-ph hep-ph physics.space-ph | null | It has often been claimed that the proposed Earth artificial satellite
LARES/WEBER-SAT-whose primary goal is, in fact, the measurement of the general
relativistic Lense-Thirring effect at a some percent level-would allow to
greatly improve, among (many) other things, the present-day (10^-13) level of
accuracy in testing the equivalence principle as well. Recent claims point
towards even two orders of magnitude better, i.e. 10^-15. In this note we show
that such a goal is, in fact, unattainable by many orders of magnitude being,
instead, the achievable level of the order of 10^-9.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:25:22 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 23:31:16 GMT"
},
{
"version": "v3",
"created": "Fri, 3 Aug 2007 16:10:56 GMT"
},
{
"version": "v4",
"created": "Wed, 26 Sep 2007 22:50:06 GMT"
},
{
"version": "v5",
"created": "Fri, 12 Oct 2007 18:41:01 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Iorio",
"Lorenzo",
""
]
] |
0706.1931 | Ali Vanderveld | R. Ali Vanderveld, Eanna E. Flanagan, Ira Wasserman | Systematic corrections to the measured cosmological constant as a result
of local inhomogeneity | 28 pages, 3 figures, revtex4; v2: corrected comments and the section
on previous work; v3: clarified wording. References added | Phys.Rev.D76:083504,2007 | 10.1103/PhysRevD.76.083504 | null | astro-ph gr-qc | null | We calculate the systematic inhomogeneity-induced correction to the
cosmological constant that one would infer from an analysis of the luminosities
and redshifts of Type Ia supernovae, assuming a homogeneous universe. The
calculation entails a post-Newtonian expansion within the framework of second
order perturbation theory, wherein we consider the effects of subhorizon
density perturbations in a flat, dust dominated universe. Within this
formalism, we calculate luminosity distances and redshifts along the past light
cone of an observer. The resulting luminosity distance-redshift relation is fit
to that of a homogeneous model in order to deduce the best-fit cosmological
constant density Omega_Lambda. We find that the luminosity distance-redshift
relation is indeed modified, by a small fraction of order 10^{-5}. When fitting
this perturbed relation to that of a homogeneous universe, we find that the
inferred cosmological constant can be surprisingly large, depending on the
range of redshifts sampled. For a sample of supernovae extending from z=0.02
out to z=0.15, we find that Omega_Lambda=0.004. The value of Omega_Lambda has a
large variance, and its magnitude tends to get larger for smaller redshifts,
implying that precision measurements from nearby supernova data will require
taking this effect into account. However, we find that this effect is likely
too small to explain the observed value of Omega_Lambda=0.7. There have been
previous claims of much larger backreaction effects. By contrast to those
calculations, our work is directly related to how observers deduce cosmological
parameters from astronomical data.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:25:37 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 21:15:46 GMT"
},
{
"version": "v3",
"created": "Tue, 19 Jun 2007 20:21:37 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Vanderveld",
"R. Ali",
""
],
[
"Flanagan",
"Eanna E.",
""
],
[
"Wasserman",
"Ira",
""
]
] |
0706.1932 | Petr Marek | Petr Marek and Radim Filip | Probabilistic purification of noisy coherent states | 11 pages, 4 figures, typo in the abstract corrected | QIC Vol.7 No.7, pp609 (2007) | null | null | quant-ph | null | A basic feasible probabilistic purification of unknown noisy coherent states,
outgoing from different state preparations with unknown mean number of thermal
photons, is proposed. The scheme is based only on a linear-optical network with
an avalanche photo-diode or heterodyne (homodyne) detection used to post-select
a successful processing. The suggested probabilistic method can produce an
output state with a lower noise than both quantum deterministic and classical
probabilistic distillation method. The purification applied in the state
preparation can increase classical capacity of communication and security of
quantum key distribution.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:49:48 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Marek",
"Petr",
""
],
[
"Filip",
"Radim",
""
]
] |
0706.1933 | Morten Bache | M. Bache, O. Bang, J. Moses and F. W. Wise | Nonlocal explanation of stationary and nonstationary regimes in cascaded
soliton pulse compression | 3 pages, 2 figures, published verison in Optics Letters. Contains
revised equations, including an updated model | Opt. Lett. 32, 2490-2492 (2007),
http://www.opticsinfobase.org.globalproxy.cvt.dk/abstract.cfm?URI=ol-32-17-2490 | 10.1364/OL.32.002490 | null | physics.optics | null | We study soliton pulse compression in materials with cascaded quadratic
nonlinearities, and show that the group-velocity mismatch creates two different
temporally nonlocal regimes. They correspond to what is known as the stationary
and nonstationary regimes. The theory accurately predicts the transition to the
stationary regime, where highly efficient pulse compression is possible.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:39:38 GMT"
},
{
"version": "v2",
"created": "Sun, 19 Aug 2007 21:06:02 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bache",
"M.",
""
],
[
"Bang",
"O.",
""
],
[
"Moses",
"J.",
""
],
[
"Wise",
"F. W.",
""
]
] |
0706.1934 | J\"org Ruppert | Jorg Ruppert, Charles Gale, Thorsten Renk, Peter Lichard, Joseph I.
Kapusta | Low Mass Dimuons Produced in Relativistic Nuclear Collisions | 4 pages, 3 figures, updated hadronic analysis | Phys.Rev.Lett.100:162301,2008 | 10.1103/PhysRevLett.100.162301 | null | hep-ph | null | The NA60 experiment has measured low-mass muon pair production in In-In
collisions at 158 A GeV with unprecedented precision. We show that this data is
reproduced very well by a dynamical model with parameters scaled from fits to
measurements of hadronic transverse mass spectra and Hanbury-Brown and Twiss
correlations in Pb-Pb and Pb-Au collisions at the same energy. The data is
consistent with in-medium properties of $\rho$ and $\omega$-mesons at finite
temperature and density as deduced from empirical forward-scattering
amplitudes. Inclusion of the vacuum decay of the $\rho$-meson after freeze-out
is necessary for an understanding of the mass and transverse momentum spectrum
of dimuons with $M \apprle 0.9 {\rm GeV}/c^2$.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:40:26 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 13:29:12 GMT"
},
{
"version": "v3",
"created": "Wed, 10 Oct 2007 18:07:54 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ruppert",
"Jorg",
""
],
[
"Gale",
"Charles",
""
],
[
"Renk",
"Thorsten",
""
],
[
"Lichard",
"Peter",
""
],
[
"Kapusta",
"Joseph I.",
""
]
] |
0706.1935 | Florent Brenguier | Florent Brenguier, Nikolai M. Shapiro, Michel Campillo, Valerie
Ferrazzini, Zacharie Duputel, Olivier Coutant, and Alexandre Nercessian | Toward Forecasting Volcanic Eruptions using Seismic Noise | Supplementary information:
http://www-lgit.obs.ujf-grenoble.fr/~fbrengui/brenguier_SI.pdf Supplementary
video:
http://www-lgit.obs.ujf-grenoble.fr/~fbrengui/brenguierMovieVolcano.avi | null | 10.1038/ngeo104 | null | physics.geo-ph | null | During inter-eruption periods, magma pressurization yields subtle changes of
the elastic properties of volcanic edifices. We use the reproducibility
properties of the ambient seismic noise recorded on the Piton de la Fournaise
volcano to measure relative seismic velocity variations of less than 0.1 % with
a temporal resolution of one day. Our results show that five studied volcanic
eruptions were preceded by clearly detectable seismic velocity decreases within
the zone of magma injection. These precursors reflect the edifice dilatation
induced by magma pressurization and can be useful indicators to improve the
forecasting of volcanic eruptions.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:41:12 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Brenguier",
"Florent",
""
],
[
"Shapiro",
"Nikolai M.",
""
],
[
"Campillo",
"Michel",
""
],
[
"Ferrazzini",
"Valerie",
""
],
[
"Duputel",
"Zacharie",
""
],
[
"Coutant",
"Olivier",
""
],
[
"Nercessian",
"Alexandre",
""
]
] |
0706.1936 | Nicola Arcozzi | N. Arcozzi, R.Rochberg, E. Sawyer | The characterization of the Carleson measures for analytic Besov spaces:
a simple proof | 12 pages | null | null | null | math.CV | null | We give a simple proof of the characterization of the Carleson measures for
the weighted analytic Besov spaces. Such characterization provides some
information on the radial variation of an analytic Besov function.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:45:31 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Arcozzi",
"N.",
""
],
[
"Rochberg",
"R.",
""
],
[
"Sawyer",
"E.",
""
]
] |
0706.1937 | Denis Perrot | Denis Perrot | Secondary invariants for Frechet algebras, quasihomomorphisms, and the
residue Chern character | Withdrawn, replaced by arXiv:0804.1042 and arXiv:0804.1048 | null | null | null | math.KT math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This paper has been replaced by arXiv:0804.1042 and arXiv:0804.1048
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:47:29 GMT"
},
{
"version": "v2",
"created": "Fri, 28 Nov 2008 11:15:50 GMT"
}
] | 2008-11-28T00:00:00 | [
[
"Perrot",
"Denis",
""
]
] |
0706.1938 | Elias Gyftopoulos | Elias P. Gyftopoulos and Michael R. von Spakovsky | Comments on the Quantum Afterburner | 5 pages | null | null | null | quant-ph | null | A process has been proposed to increase the efficiency of an ideal Otto cycle
via a quantum heat engine that has no cooler reservoir. We show that such a
process is not feasible.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:52:56 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Gyftopoulos",
"Elias P.",
""
],
[
"von Spakovsky",
"Michael R.",
""
]
] |
0706.1939 | Thomas Bania | T. M. Bania, Dana S. Balser, Robert T. Rood, T. L. Wilson and Jennifer
M. LaRocque | 3-He in the Milky Way Interstellar Medium: Ionization Structure | 36 pages, 4 figures To appear Astrophysical Journal, 20 August 2007,
vol 665, no 2 | Astrophys.J.664:915-927,2007 | 10.1086/519453 | null | astro-ph | null | The cosmic abundance of the 3-He isotope has important implications for many
fields of astrophysics. We are using the 8.665 GHz hyperfine transition of
3-He+ to determine the 3-He/H abundance in Milky Way HII regions and planetary
nebulae. This is one in a series of papers in which we discuss issues involved
in deriving accurate 3-He/H abundance ratios from the available measurements.
Here we describe the ionization correction we use to convert the 3-He+/H+
abundance, y3+, to the 3-He/H abundance, y3. In principle the nebular
ionization structure can significantly influence the y3 derived for individual
sources. We find that in general there is insufficient information available to
make a detailed ionization correction. Here we make a simple correction and
assess its validity. The correction is based on radio recombination line
measurements of H+ and 4-He+, together with simple core-halo source models. We
use these models to establish criteria that allow us to identify sources that
can be accurately corrected for ionization and those that cannot. We argue that
this effect cannot be very large for most of the sources in our observational
sample. For a wide range of models of nebular ionization structure we find that
the ionization correction factor varies from 1 to 1.8. Although large
corrections are possible, there would have to be a conspiracy between the
density and ionization structure for us to underestimate the ionization
correction by a substantial amount.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 15:56:51 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Bania",
"T. M.",
""
],
[
"Balser",
"Dana S.",
""
],
[
"Rood",
"Robert T.",
""
],
[
"Wilson",
"T. L.",
""
],
[
"LaRocque",
"Jennifer M.",
""
]
] |
0706.1940 | Jonathan Crofts | Jonathan J. Crofts | Efficient method for detection of periodic orbits in chaotic maps and
flows | PhD thesis, 119 pages. Due to restrictions on the size of files
uploaded, some of the figures are of rather poor quality. If necessary a
quality copy may be obtained (approximately 1MB in pdf) by emailing me at
[email protected] | null | null | null | nlin.CD | null | An algorithm for detecting unstable periodic orbits in chaotic systems [Phys.
Rev. E, 60 (1999), pp. 6172-6175] which combines the set of stabilising
transformations proposed by Schmelcher and Diakonos [Phys. Rev. Lett., 78
(1997), pp. 4733-4736] with a modified semi-implicit Euler iterative scheme and
seeding with periodic orbits of neighbouring periods, has been shown to be
highly efficient when applied to low-dimensional system. The difficulty in
applying the algorithm to higher dimensional systems is mainly due to the fact
that the number of stabilising transformations grows extremely fast with
increasing system dimension. In this thesis, we construct stabilising
transformations based on the knowledge of the stability matrices of already
detected periodic orbits (used as seeds). The advantage of our approach is in a
substantial reduction of the number of transformations, which increases the
efficiency of the detection algorithm, especially in the case of
high-dimensional systems. The performance of the new approach is illustrated by
its application to the four-dimensional kicked double rotor map, a
six-dimensional system of three coupled H\'enon maps and to the
Kuramoto-Sivashinsky system in the weakly turbulent regime.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 16:55:07 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 20:54:01 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Crofts",
"Jonathan J.",
""
]
] |
0706.1941 | Martin Wolf | Lionel J. Mason, Martin Wolf | Twistor Actions for Self-Dual Supergravities | v2: 29 pages, substantially revised and rewritten with a clearer and
more complete treatment, an extra 8 pages, replaced with version to appear in
CMP | Commun.Math.Phys.288:97-123,2009 | 10.1007/s00220-009-0732-5 | Imperial-TP-MW-02/07 | hep-th gr-qc math-ph math.DG math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give holomorphic Chern-Simons-like action functionals on supertwistor
space for self-dual supergravity theories in four dimensions, dealing with
N=0,...,8 supersymmetries, the cases where different parts of the R-symmetry
are gauged, and with or without a cosmological constant. The gauge group is
formally the group of holomorphic Poisson transformations of supertwistor space
where the form of the Poisson structure determines the amount of R-symmetry
gauged and the value of the cosmological constant. We give a formulation in
terms of a finite deformation of an integrable \dbar-operator on a supertwistor
space, i.e., on regions in CP^{3|8}. For N=0, we also give a formulation that
does not require the choice of a background.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:09:12 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Nov 2008 12:21:47 GMT"
}
] | 2009-04-17T00:00:00 | [
[
"Mason",
"Lionel J.",
""
],
[
"Wolf",
"Martin",
""
]
] |
0706.1942 | Wu Jing | Xuehan Cheng, Wu Jing | On Jordan Derivations of Triangular Algebras | 5 pages | null | null | null | math.RA | null | In this short note we prove that every Jordan derivation of triangular
algebras is a derivation.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 16:14:44 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Cheng",
"Xuehan",
""
],
[
"Jing",
"Wu",
""
]
] |
0706.1943 | Assaf Naor | Tim Austin, Assaf Naor, Yuval Peres | The wreath product of Z with Z has Hilbert compression exponent 2/3 | Removed a reference to the lower bound of 2/3 for the Hilbert
compression of Z wreath Z in math/0603138 since the proof is incorrect; added
a reference which contains a correct proof (the results of this paper remain
unchanged). Added Remark 2.2 which shows why Z wreath Z has Hilbert
compression exponent at least 2/3 | null | null | null | math.MG math.FA math.GR | null | Let G be a finitely generated group, equipped with the word metric d
associated with some finite set of generators. The Hilbert compression exponent
of G is the supremum over all $\alpha\ge 0$ such that there exists a Lipschitz
mapping $f:G\to L_2$ and a constant $c>0$ such that for all $x,y\in G$ we have
$\|f(x)-f(y)\|_2\ge cd(x,y)^\alpha.$ In \cite{AGS06} it was shown that the
Hilbert compression exponent of the wreath product $\Z\bwr \Z $ is at most
$\frac34$, and in \cite{NP07} was proved that this exponent is at least
$\frac23$. Here we show that $\frac23$ is the correct value. Our proof is based
on an application of K. Ball's notion of Markov type.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 16:17:25 GMT"
},
{
"version": "v2",
"created": "Sat, 16 Jun 2007 20:32:29 GMT"
},
{
"version": "v3",
"created": "Thu, 9 Aug 2007 00:01:56 GMT"
},
{
"version": "v4",
"created": "Mon, 13 Aug 2007 02:39:34 GMT"
}
] | 2007-08-13T00:00:00 | [
[
"Austin",
"Tim",
""
],
[
"Naor",
"Assaf",
""
],
[
"Peres",
"Yuval",
""
]
] |
0706.1944 | Marco Chiaberge | Alessandro Capetti (1), David J. Axon (2), Marco Chiaberge (3),
William B. Sparks (3), F. Duccio Macchetto (3,4), Misty Cracraft (3),
Annalisa Celotti (5) ((1) INAF - Osservatorio Astronomico di Torino, Italy
(2) Rochester Institute of Technology, USA (3) Space Telescope Science
Institute, USA (4) Affiliated with ESA's Research & Space Science Department,
(5) SISSA/ISAS, Italy) | On the nature of optical nuclei in FR I radio-galaxies from ACS/HST
imaging polarimetry | 16 page, 10 figures, accepted for publication in A&A | null | 10.1051/0004-6361:20077370 | null | astro-ph | null | We obtained optical imaging polarimetry with the ACS/HRC aboard the HST of
the 9 closest radio-galaxies in the 3C catalogue with an FR I morphology. The
nuclear sources seen in direct HST images in these galaxies are found to be
highly polarized with levels in the range ~2-11 % with a median value of 7 %.
We discuss the different mechanisms that produce polarized emission and
conclude that the only viable interpretation is a synchrotron origin for the
optical nuclei. This idea is strengthened by the analogy with the polarization
properties of BL Lac objects, providing also further support to the FRI/BL Lac
unified model. This confirms previous suggestions that the dominant emission
mechanism in low luminosity radio-loud AGN is related to non-thermal radiation
produced by the base of their jets. In addition to the nuclear polarization
(and to the large scale optical jets), polarization is detected co-spatially
with the dusty circumnuclear disks, likely due to dichroic transmission; the
polarization vectors are tangential to the disks as expected when the magnetic
field responsible for the grains alignment is stretched by differential
rotation. We explored the possibility to detect the polarimetric signature of a
misaligned radiation beam in FR I, expected in our sources in the frame of the
FR I/ BL Lac unification. We did not find this effect in any of the galaxies,
but our the results are not conclusive on whether a misaligned beam is indeed
present in FR I.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 16:27:15 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Capetti",
"Alessandro",
""
],
[
"Axon",
"David J.",
""
],
[
"Chiaberge",
"Marco",
""
],
[
"Sparks",
"William B.",
""
],
[
"Macchetto",
"F. Duccio",
""
],
[
"Cracraft",
"Misty",
""
],
[
"Celotti",
"Annalisa",
""
]
] |
0706.1945 | Africa Castillo-Morales | A. Castillo-Morales (1), J. Jimenez-Vicente (2), E. Mediavilla (3), E.
Battaner (2) ((1) Universidad Complutense Madrid, Spain, (2) Universidad de
Granada, Spain, (3) Instituto de Astrofisica de Canarias, Spain) | Non-circular motion evidences in the circumnuclear region of M100 (NGC
4321) | 11 pages, 11 figures, accepted for publication in MNRAS | null | 10.1111/j.1365-2966.2007.12104.x | null | astro-ph | null | We analyse new integral field spectroscopy of the inner region (central 2.5
kpc) of the spiral galaxy NGC 4321 to study the peculiar kinematics of this
region. Fourier analysis of the velocity residuals obtained by subtracting an
axisymmetric rotation model from the $\rm H\alpha$ velocity field, indicates
that the distortions are {\em global} features generated by an $m=2$
perturbation of the gravitational potential which can be explained by the
nuclear bar. This bar has been previously observed in the near-infrared but not
in the optical continuum dominated by star formation. We detect the optical
counterpart of this bar in the 2D distribution of the old stellar population
(inferred from the equivalent width map of the stellar absorption lines). We
apply the Tremaine--Weinberg method to the stellar velocity field to calculate
the pattern speed of the inner bar, obtaining a value of
$\Omega_b$=160$\pm70\rm km s^{-1} kpc^{-1} $. This value is considerably la
rger than the one obtained when a simple bar model is considered. However the
uncertainties in the pattern speed determination prevent us to give support to
alternative scenarios.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 16:33:38 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Castillo-Morales",
"A.",
""
],
[
"Jimenez-Vicente",
"J.",
""
],
[
"Mediavilla",
"E.",
""
],
[
"Battaner",
"E.",
""
]
] |
0706.1946 | Peihong Gu | Pei-Hong Gu | Origin of matter in the universe | 6 pages, 7 figures. Comment on proton decay improved. Accepted by PLB | Phys.Lett.B657:103-106,2007 | 10.1016/j.physletb.2007.08.095 | null | hep-ph | null | We extend the standard model with two iso-singlet color triplet scalars, one
singlet real scalar and one singlet fermion. The new fields are odd under an
unbroken Z_2 discrete symmetry while the standard model particles are even. The
decays of the singlet real scalar into three standard model quarks (antiquarks)
with three singlet antifermions (fermions), which explicitly violate the baryon
number, will become effective after the electroweak phase transition and then
produce the observed baryon asymmetry in the universe through the loop diagram
involving the exchange of the W gauge boson. The singlet fermion can serve as
the candidate for cold dark matter. In our model, all new particles with masses
below the TeV scale can be detected by the forthcoming collider experiments or
the next generation experiments for neutron-antineutron oscillations.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:44:10 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Jun 2007 09:50:31 GMT"
},
{
"version": "v3",
"created": "Fri, 31 Aug 2007 19:57:01 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gu",
"Pei-Hong",
""
]
] |
0706.1947 | Thierry Ruchon | T. Ruchon, C. P. Hauri, K. Varju, E. Gustafsson, R. Lopez-Martens and
A. L'Huillier | Macroscopic effects in attosecond pulse generation | 5 pages 4 figures | null | 10.1088/1367-2630/10/2/025027 | null | physics.optics physics.atom-ph | null | We examine how the generation and propagation of high-order harmonics in a
partly ionized gas medium affect their strength and synchronization. The
temporal properties of the resulting attosecond pulses generated in long gas
targets can be significantly influenced by macroscopic effects, in particular
by the intensity in the medium and the degree of ionization. Under some
conditions, the use of gas targets longer than the absorption length can lead
to the generation of self-compressed attosecond pulses. We show this effect
experimentally, using long argon-filled gas cells as generating medium.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:25:59 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ruchon",
"T.",
""
],
[
"Hauri",
"C. P.",
""
],
[
"Varju",
"K.",
""
],
[
"Gustafsson",
"E.",
""
],
[
"Lopez-Martens",
"R.",
""
],
[
"L'Huillier",
"A.",
""
]
] |
0706.1948 | Nikolaos Tombros | Nikolaos Tombros, Csaba Jozsa, Mihaita Popinciuc, Harry T. Jonkman and
Bart J. van Wees (Physics of Nanodevices and Molecular Electronics, Zernike
Institute for Advanced Materials, The Netherlands) | Electronic spin transport and spin precession in single graphene layers
at room temperature | null | Nature 448,571-574 (2007) | 10.1038/nature06037 | null | cond-mat.mes-hall | null | The specific band structure of graphene, with its unique valley structure and
Dirac neutrality point separating hole states from electron states has led to
the observation of new electronic transport phenomena such as anomalously
quantized Hall effects, absence of weak localization and the existence of a
minimum conductivity. In addition to dissipative transport also supercurrent
transport has already been observed. It has also been suggested that graphene
might be a promising material for spintronics and related applications, such as
the realization of spin qubits, due to the low intrinsic spin orbit
interaction, as well as the low hyperfine interaction of the electron spins
with the carbon nuclei. As a first step in the direction of graphene
spintronics and spin qubits we report the observation of spin transport, as
well as Larmor spin precession over micrometer long distances using single
graphene layer based field effect transistors. The non-local spin valve
geometry was used, employing four terminal contact geometries with
ferromagnetic cobalt electrodes, which make contact to the graphene sheet
through a thin oxide layer. We observe clear bipolar (changing from positive to
negative sign) spin signals which reflect the magnetization direction of all 4
electrodes, indicating that spin coherence extends underneath all 4 contacts.
No significant changes in the spin signals occur between 4.2K, 77K and room
temperature. From Hanle type spin precession measurements we extract a spin
relaxation length between 1.5 and 2 micron at room temperature, only weakly
dependent on charge density, which is varied from n~0 at the Dirac neutrality
point to n = 3.6 10^16/m^2. The spin polarization of the ferromagnetic contacts
is calculated from the measurements to be around 10%.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 16:46:30 GMT"
}
] | 2011-05-05T00:00:00 | [
[
"Tombros",
"Nikolaos",
"",
"Physics of Nanodevices and Molecular Electronics, Zernike\n Institute for Advanced Materials, The Netherlands"
],
[
"Jozsa",
"Csaba",
"",
"Physics of Nanodevices and Molecular Electronics, Zernike\n Institute for Advanced Materials, The Netherlands"
],
[
"Popinciuc",
"Mihaita",
"",
"Physics of Nanodevices and Molecular Electronics, Zernike\n Institute for Advanced Materials, The Netherlands"
],
[
"Jonkman",
"Harry T.",
"",
"Physics of Nanodevices and Molecular Electronics, Zernike\n Institute for Advanced Materials, The Netherlands"
],
[
"van Wees",
"Bart J.",
"",
"Physics of Nanodevices and Molecular Electronics, Zernike\n Institute for Advanced Materials, The Netherlands"
]
] |
0706.1949 | Massimo Ostilli | Massimo Ostilli | Ising spin glass models versus Ising models: an effective mapping at
high temperature III. Rigorous formulation and detailed proof for general
graphs | 25 pages, 5 figures, made statements in Sec. 10 clearer | J. Stat. Mech. (2007) P09010 | 10.1088/1742-5468/2007/09/P09010 | null | cond-mat.dis-nn cond-mat.stat-mech | null | Recently, it has been shown that, when the dimension of a graph turns out to
be infinite dimensional in a broad sense, the upper critical surface and the
corresponding critical behavior of an arbitrary Ising spin glass model defined
over such a graph, can be exactly mapped on the critical surface and behavior
of a non random Ising model. A graph can be infinite dimensional in a strict
sense, like the fully connected graph, or in a broad sense, as happens on a
Bethe lattice and in many random graphs. In this paper, we firstly introduce
our definition of dimensionality which is compared to the standard definition
and readily applied to test the infinite dimensionality of a large class of
graphs which, remarkably enough, includes even graphs where the tree-like
approximation (or, in other words, the Bethe-Peierls approach), in general, may
be wrong. Then, we derive a detailed proof of the mapping for all the graphs
satisfying this condition. As a byproduct, the mapping provides immediately a
very general Nishimori law.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 16:47:58 GMT"
},
{
"version": "v2",
"created": "Thu, 14 Jun 2007 16:54:52 GMT"
},
{
"version": "v3",
"created": "Wed, 1 Aug 2007 10:32:13 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Ostilli",
"Massimo",
""
]
] |
0706.1950 | Simone Fratini | S. Fratini, A. F. Morpurgo, S. Ciuchi | Electron-phonon and electron-electron interactions in organic field
effect transistors | proceedings of the SMEC'07 conference, submitted to the Journal of
Physics and Chemistry of Solids | null | 10.1016/j.jpcs.2008.03.039 | null | cond-mat.str-el | null | Recent experiments have demonstrated that the performances of organic FETs
strongly depend on the dielectric properties of the gate insulator. In
particular, it has been shown that the temperature dependence of the mobility
evolves from a metallic-like to an insulating behavior upon increasing the
dielectric constant of the gate material. This phenomenon can be explained in
terms of the formation of small polarons, due to the polar interaction of the
charge carriers with the phonons at the organic/dielectric interface. Building
on this model, the possible consequences of the Coulomb repulsion between the
carriers at high concentrations are analyzed.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:14:16 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Fratini",
"S.",
""
],
[
"Morpurgo",
"A. F.",
""
],
[
"Ciuchi",
"S.",
""
]
] |
0706.1951 | J. M. Taylor | J. M. Taylor and T. Calarco | Wigner crystals of ions as quantum hard drives | 5 pages, 4 figures | null | 10.1103/PhysRevA.78.062331 | null | quant-ph | null | Atomic systems in regular lattices are intriguing systems for implementing
ideas in quantum simulation and information processing. Focusing on laser
cooled ions forming Wigner crystals in Penning traps, we find a robust and
simple approach to engineering non-trivial 2-body interactions sufficient for
universal quantum computation. We then consider extensions of our approach to
the fast generation of large cluster states, and a non-local architecture using
an asymmetric entanglement generation procedure between a Penning trap system
and well-established linear Paul trap designs.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 16:55:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Taylor",
"J. M.",
""
],
[
"Calarco",
"T.",
""
]
] |
0706.1952 | Edgar Delgado-Eckert MS | Edgar Delgado-Eckert | Canonical representatives for residue classes of a polynomial ideal and
orthogonality | 19 pages; Submitted to journal, currently under review | null | null | null | math.AC math.AG | null | The aim of this paper is to unveil an unexpected relationship between the
normal form of a polynomial with respect to a polynomial ideal and the more
geometric concept of orthogonality. We present a new way to calculate the
normal form of a polynomial with respect to a polynomial ideal I in the ring of
multivariate polynomials over a field K, provided the field K is finite and the
ideal I is a vanishing ideal. In order to use the concept of orthogonality, we
introduce a symmetric bilinear form on a vector space over a finite field.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:05:08 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Delgado-Eckert",
"Edgar",
""
]
] |
0706.1953 | Stuart White | Ken Dykema, Allan Sinclair, Roger Smith and Stuart White | Generators of II_1 Factors | 36 Pages, section 8 rewritten | Oper. Matrices 2, no 4 (2008), 555-582. | null | null | math.OA | null | In 2005, Shen introduced a new invariant, $\mathcal G(N)$, of a diffuse von
Neumann algebra $N$ with a fixed faithful trace, and he used this invariant to
give a unified approach to showing that large classes of ${\mathrm{II}}_1$
factors $M$ are singly generated. This paper focuses on properties of this
invariant. We relate $\mathcal G(M)$ to the number of self-adjoint generators
of a ${\mathrm{II}}_1$ factor $M$: if $\mathcal G(M)<n/2$, then $M$ is
generated by $n+1$ self-adjoint operators, whereas if $M$ is generated by $n+1$
self-adjoint operators, then $\mathcal G(M)\leq n/2$. The invariant $\mathcal
G(\cdot)$ is well-behaved under amplification, satisfying $\mathcal
G(M_t)=t^{-2}\mathcal G(M)$ for all $t>0$. In particular, if $\mathcal
G(\mathcal L\mathbb F_r)>0$ for any particular $r>1$, then the free group
factors are pairwise non-isomorphic and are not singly generated for
sufficiently large values of $r$. Estimates are given for forming free products
and passing to finite index subfactors and the basic construction. We also
examine a version of the invariant $\mathcal G_{\text{sa}}(M)$ defined only
using self-adjoint operators; this is proved to satisfy $\mathcal
G_{\text{sa}}(M)=2\mathcal G(M)$. Finally we give inequalities relating a
quantity involved in the calculation of $\mathcal G(M)$ to the free-entropy
dimension $\delta_0$ of a collection of generators for $M$.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:10:39 GMT"
},
{
"version": "v2",
"created": "Fri, 2 Nov 2007 03:17:59 GMT"
}
] | 2008-12-15T00:00:00 | [
[
"Dykema",
"Ken",
""
],
[
"Sinclair",
"Allan",
""
],
[
"Smith",
"Roger",
""
],
[
"White",
"Stuart",
""
]
] |
0706.1954 | Boaz Tsaban | Boaz Tsaban | SPM Bulletin 21 | null | null | null | null | math.GN math.CO math.LO | null | Contents: 1. Editor's note; 2. Personal impressions from the SPM07 meeting;
3. Research announcements; 3.1. Coloring ordinals by reals; 3.2. Long Borel
Hierarchies; 3.3. Rothberger's property in finite powers; 3.4. Special subsets
of the reals and tree forcing notions; 3.5. All automorphisms of the Calkin
algebra are inner; 3.6. Continuous selections and sigma-spaces; 3.7. On the
closure of the diagonal of a T1-space; 3.8. Splitting families and Noetherian
type; 3.9. Even more simple cardinal invariants; 3.10. A classification of CO
spaces which are continuous images of compact ordered spaces; 4. Problem of the
Issue
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:15:06 GMT"
}
] | 2008-12-31T00:00:00 | [
[
"Tsaban",
"Boaz",
""
]
] |
0706.1955 | Andrew Ho | A. F. Ho and A. J. Schofield | Effect of disorder on a Pomeranchuk instability | 4.1 pages, 3 figs. Version as published in EPL. Added data of
Sr3Ru2O7 to theory curves of Fig.2, and some clarification of derivation of
results | European Physics Letters 84, p.27007 (2008) | 10.1209/0295-5075/84/27007 | null | cond-mat.str-el cond-mat.dis-nn | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the effect of disorder on the order parameter equation and
transition temperature of a Pomeranchuk-type Fermi-surface instability using
replica mean field theory. We consider the example of a phase transition to a
$d_{x^2 +y^2}$ type Fermi surface distortion, and show that, in the regime
where such a transition is second order, the transition temperature is reduced
by disorder in essentially the same way as that for a d-wave superconductor. We
argue that observing this disorder dependence of metal-to-metal transition
might be a useful indicator of a finite angular momentum Fermi surface
distortion.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:35:13 GMT"
},
{
"version": "v2",
"created": "Fri, 20 Feb 2009 17:30:28 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ho",
"A. F.",
""
],
[
"Schofield",
"A. J.",
""
]
] |
0706.1956 | Milton Ferreira | Milton Ferreira | Spherical Continuous Wavelet Transforms arising from sections of the
Lorentz group | 30 pages, 1 figure This paper has been withdrawn by the author since
it differs from its final version | null | null | null | math.RT math.GR | null | We consider the conformal group of the unit sphere $S^{n-1},$ the so-called
proper Lorentz group Spin$^+(1,n),$ for the study of spherical continuous
wavelet transforms (CWT). Our approach is based on the method for construction
of general coherent states associated to square integrable group
representations over homogeneous spaces. The underlying homogeneous space is an
extension to the whole of the group Spin$^+(1,n)$ of the factorization of the
gyrogroup of the unit ball by an appropriate gyro-subgroup. Sections on this
homogeneous space are constituted by rotations of the subgroup Spin$(n)$ and
M\"{o}bius transformations of the type $\phi_a(x)=(x-a)(1+ax)^{-1},$ where $a$
belongs to a given section on a homogeneous space of the unit ball. This
extends in a natural way the work of Antoine and Vandergheynst to anisotropic
conformal dilations.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:36:04 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 12:42:42 GMT"
},
{
"version": "v3",
"created": "Thu, 8 Nov 2007 14:33:54 GMT"
},
{
"version": "v4",
"created": "Wed, 7 Aug 2013 06:51:51 GMT"
}
] | 2013-08-08T00:00:00 | [
[
"Ferreira",
"Milton",
""
]
] |
0706.1957 | Stephen G. Naculich | Stephen G. Naculich and Benjamin H. Ripman | Level-rank duality of untwisted and twisted D-branes of the so(N)_K WZW
model | 18 pages | Nucl.Phys.B787:135-151,2007 | 10.1016/j.nuclphysb.2007.07.011 | BOW-PH-140 | hep-th | null | We analyze the level-rank duality of untwisted and epsilon-twisted D-branes
of the so(N)_K WZW model. Untwisted D-branes of so(N)_K are characterized by
integrable tensor and spinor representations of so(N)_K. Level-rank duality
maps untwisted so(N)_K D-branes corresponding to (equivalence classes of)
tensor representations onto those of so(K)_N. The epsilon-twisted D-branes of
so(2n)_2k are characterized by (a subset of) integrable tensor and spinor
representations of so(2n-1)_2k+1. Level-rank duality maps spinor
epsilon-twisted so(2n)_2k D-branes onto those of so(2k)_2n. For both untwisted
and epsilon-twisted D-branes, we prove that the spectrum of an open string
ending on these D-branes is isomorphic to the spectrum of an open string ending
on the level-rank-dual D-branes.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:37:25 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Naculich",
"Stephen G.",
""
],
[
"Ripman",
"Benjamin H.",
""
]
] |
0706.1958 | Jorge Caravantes | Jorge Caravantes | Fano threefolds with noncyclic torsion in the divisor class group | 13 pages | null | null | null | math.AG | null | In this note we study Fano threefolds with noncyclic torsion in the divisor
class group. Since they can all be obtained as quotients of Fano threefolds, we
get also all examples that can be obtained as quotients of low codimension
Fanos in the weighted projective space.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 17:40:12 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Caravantes",
"Jorge",
""
]
] |
0706.1959 | Elena Dalla Bonta' | E. Dalla Bonta' (1,2), L. Ferrarese (2), E. M. Corsini (1), J.
Miralda-Escude (3), L. Coccato (4), A. Pizzella (1) ((1) Padua University,
Italy, (2) Herzberg Institute of Astrophysics, Canada, (3) Institut de
Ciencies de l'Espai (CSIC-IEEC)/ICREA, Spain, (4) Max-Planck-Institut fuer
extraterrestrische Physik, Germany) | The Black Hole Mass of Abell 1836-BCG and Abell 3565-BCG | 4 pages, 3 figures, Mem SAIt in press, Proceedings of the 51st Annual
Meeting of the Italian Astronomical Society, Florence, April 17-20, 2007 | null | null | null | astro-ph | null | Two brightest cluster galaxies (BCGs), namely Abell 1836-BCG and Abell
3565-BCG, were observed with the Advanced Camera for Surveys (ACS) and the
Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space
Telescope. By modeling the available photometric and kinematic data, it
resulted that the mass of Abell 1836-BCG and Abell 3565-BCG are
M_bh=4.8(+0.8,-0.7)x10^9 M_sun and M_bh=1.3(+0.3,-0.4)x10^9 M_sun at 1 sigma
confidence level, respectively.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:11:47 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Bonta'",
"E. Dalla",
""
],
[
"Ferrarese",
"L.",
""
],
[
"Corsini",
"E. M.",
""
],
[
"Miralda-Escude",
"J.",
""
],
[
"Coccato",
"L.",
""
],
[
"Pizzella",
"A.",
""
]
] |
0706.1960 | Sait Umar | A.S. Umar and V.E. Oberacker | Compressibility and equation of state of finite nuclei | 4 pages, 3 figures | Phys.Rev.C76:024316,2007 | 10.1103/PhysRevC.76.024316 | null | nucl-th | null | We present a new approach for calculating the nuclear equation of state and
compressibility for finite nuclei using the density-constrained Hartree-Fock
method.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:19:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Umar",
"A. S.",
""
],
[
"Oberacker",
"V. E.",
""
]
] |
0706.1961 | Joseph D. Masters | Joseph D. Masters | Kleinian groups with ubiquitous surface subgroups | 7 pages, 5 figures | null | null | null | math.GT | null | We show that every finitely-generated free subgroup of a right-angled,
co-compact Kleinian reflection group is contained in a surface subgroup.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:26:02 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Masters",
"Joseph D.",
""
]
] |
0706.1962 | Robert Wittenmyer | Robert A. Wittenmyer, Michael Endl, William D. Cochran, and Harold F.
Levison | Dynamical and Observational Constraints on Additional Planets in Highly
Eccentric Planetary Systems | Accepted for publication in AJ | Astron.J.134:1276-1284,2007 | 10.1086/520880 | null | astro-ph | null | Long time coverage and high radial velocity precision have allowed for the
discovery of additional objects in known planetary systems. Many of the
extrasolar planets detected have highly eccentric orbits, which raises the
question of how likely those systems are to host additional planets. We
investigate six systems which contain a very eccentric (e>0.6) planet: HD 3651,
HD 37605, HD 45350, HD 80606, HD 89744, and 16 Cyg B. We present updated
radial-velocity observations and orbital solutions, search for additional
planets, and perform test particle simulations to find regions of dynamical
stability. The dynamical simulations show that short-period planets could exist
in the HD 45350 and 16 Cyg B systems, and we use the observational data to set
tight detection limits, which rule out additional planets down to a few Neptune
masses in the HD 3651, HD 45350, and 16 Cyg B systems.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:44:01 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Wittenmyer",
"Robert A.",
""
],
[
"Endl",
"Michael",
""
],
[
"Cochran",
"William D.",
""
],
[
"Levison",
"Harold F.",
""
]
] |
0706.1963 | Lado Samushia | Lado Samushia, Gang Chen and Bharat Ratra | Galaxy Cluster Gas Mass Fraction and Hubble Parameter versus Redshift
Constraints on Dark Energy | 11 pages, 3 figures | null | null | null | astro-ph | null | Galaxy cluster gas mass fraction versus redshift data and Hubble parameter
versus redshift data are used to jointly constrain dark energy models. These
constraints favor the Einstein cosmological constant limit of dark energy but
do not strongly rule out slowly-evolving dark energy.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:30:15 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Samushia",
"Lado",
""
],
[
"Chen",
"Gang",
""
],
[
"Ratra",
"Bharat",
""
]
] |
0706.1964 | C. Q. Geng | Chian-Shu Chen, C.Q. Geng, J.N. Ng, J.M.S. Wu | Testing Radiative Neutrino Mass Generation at the LHC | 22 pages, 13 figures, typos corrected | JHEP 0708:022,2007 | 10.1088/1126-6708/2007/08/022 | null | hep-ph hep-ex | null | We have investigated in detail a model that contains an additional SU(2)
singlet and triplet scalar fields than the Standard Model (SM). This allows the
radiative generation of Majorana neutrino masses at two-loop order with the
help of doubly charged Higgs bosons that arise from the extended Higgs sector.
We studied in detail the phenomenology of the Higgs and neutrino sectors of the
model. We give the analytical form of the masses of scalar and pseudoscalar
bosons and their mixings, and the structure of the active neutrino mass matrix.
It is found that the model accommodates only normal neutrino mass hierarchy,
and that there is a large parameter space where the doubly charged Higgs can be
observed at the LHC, thereby making it testable at the LHC. Furthermore, the
neutrino-less double beta ($\nonu$) decays arise predominantly from exchange
processes involving the doubly charged Higgs, whose existence is thus
unmistakable if $\nonu$ decays are observed. The production and decays of the
doubly charged Higgs are analyzed, and distinct and distinguishing signals are
discussed.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:30:34 GMT"
},
{
"version": "v2",
"created": "Mon, 18 Jun 2007 15:03:18 GMT"
},
{
"version": "v3",
"created": "Mon, 30 Jul 2007 01:06:49 GMT"
}
] | 2009-01-06T00:00:00 | [
[
"Chen",
"Chian-Shu",
""
],
[
"Geng",
"C. Q.",
""
],
[
"Ng",
"J. N.",
""
],
[
"Wu",
"J. M. S.",
""
]
] |
0706.1965 | Adam J. Burgasser | Adam J. Burgasser (MIT) | SDSS J080531.84+481233.0: An Unresolved L Dwarf/T Dwarf Binary | 11 pages, 4 figures, accepted by AJ | Astron.J.134:1330-1336,2007 | 10.1086/520878 | null | astro-ph | null | SDSS J080531.84+481233.0 is a peculiar L-type dwarf that exhibits unusually
blue near-infrared and mid-infrared colors and divergent optical (L4) and
near-infrared (L9.5) spectral classifications. These peculiar spectral traits
have been variously attributed to condensate cloud effects or subsolar
metallicity. Here I present an improved near-infrared spectrum of this source
which further demonstrates the presence of weak CH4 absorption at 1.6 micron
but no corresponding band at 2.2 micron. It is shown that these features can be
collectively reproduced by the combined light spectrum of a binary with L4.5
and T5 components, as deduced by spectral template matching. Thus, SDSS
J080531.84+481233.0 appears to be a new low-mass binary straddling the L
dwarf/T dwarf transition, an evolutionary phase for brown dwarfs that remains
poorly understood by current theoretical models. The case of SDSS
J080531.84+481233.0 further illustrates how a select range of L dwarf/T dwarf
binaries could be identified and characterized without the need for high
angular resolution imaging or radial velocity monitoring, potentially
alleviating some of the detection biases and limitations inherent to such
techniques.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:47:29 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Burgasser",
"Adam J.",
"",
"MIT"
]
] |
0706.1966 | Elias Gyftopoulos | Elias P. Gyftopoulos | On the lack of relation between physics and "Quantum discord and
Maxwell's demons" | 6 pages | null | null | null | quant-ph | null | The information-theoretic arguments presented in a recent publication on
"Quantum discord and Maxwell's demons" are discussed, and found not to address
the problem specified by Maxwell. Two interrelated and definitive exorcisms of
the demon, one purely thermodynamic, and the other quantum-thermodynamic are
briefly discussed. For each of the two exorcisms, the demon is shown to be
incapable to accomplish his assignment neither because of limitations arising
from information-theoretic tools at his disposal, nor because of the value of
his IQ. The limitations are due to the physics of the state of the system on
which he is asked to perform his demonic acts.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:48:55 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Gyftopoulos",
"Elias P.",
""
]
] |
0706.1967 | Walter J. Maciel | T. P. Idiart, W. J. Maciel, R. D. D. Costa | Chemical evolution of the Small Magellanic Cloud based on planetary
nebulae | 11 pages, 6 figures, accepted for publication in Astronomy and
Astrophysics | null | 10.1051/0004-6361:20077674 | null | astro-ph | null | We investigate the chemical evolution of the Small Magellanic Cloud (SMC)
based on abundance data of planetary nebulae (PNe). The main goal is to
investigate the time evolution of the oxygen abundance in this galaxy by
deriving an age-metallicity relation. Such a relation is of fundamental
importance as an observational constraint of chemical evolution models of the
SMC. We have used high quality PNe data in order to derive the properties of
the progenitor stars, so that the stellar ages could be estimated. We collected
a large number of measured spectral fluxes for each nebula, and derived
accurate physical parameters and nebular abundances. New spectral data for a
sample of SMC PNe obtained between 1999 and 2002 are also presented. These data
are used together with data available in the literature to improve the accuracy
of the fluxes for each spectral line. We obtained accurate chemical abundances
for PNe in the Small Magellanic Cloud, which can be useful as tools in the
study of the chemical evolution of this galaxy and of Local Group galaxies. We
present the resulting oxygen versus age diagram and a similar relation
involving the [Fe/H] metallicity based on a correlation with stellar data. We
discuss the implications of the derived age-metallicity relation for the SMC
formation, in particular by suggesting a star formation burst in the last 2-3
Gyr.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:54:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Idiart",
"T. P.",
""
],
[
"Maciel",
"W. J.",
""
],
[
"Costa",
"R. D. D.",
""
]
] |
0706.1968 | Andrzej Madrecki Phd | Andrzej Madrecki | The Riemann hypothesis - an elementary analytic approach based on
complex Laplace transform | 25 pages | null | null | null | math.GM | null | An elementary analytic proof of the famous Riemann hypothesis is given. The
main "accent" of the proof is a both using of the 2-dimensional double real and
complex Laplace integral representations of the Green function $\mid z
\mid^{-2}$.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:54:22 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Madrecki",
"Andrzej",
""
]
] |
0706.1969 | Diego Cordoba | Antonio Cordoba, Diego Cordoba, and Marco A. Fontelos | Formation of singularities for a transport equation with nonlocal
velocity | 13 pages, published version | Ann. of Math. (2) 162 (2005), no. 3, 1377--1389 | null | null | math.AP | null | We study a 1D transport equation with nonlocal velocity and show the
formation of singularities in finite time for a generic family of initial data.
By adding a diffusion term the finite time singularity is prevented and the
solutions exist globally in time.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:55:36 GMT"
}
] | 2007-06-14T00:00:00 | [
[
"Cordoba",
"Antonio",
""
],
[
"Cordoba",
"Diego",
""
],
[
"Fontelos",
"Marco A.",
""
]
] |
0706.1970 | Larry Ford | L.H. Ford and Thomas A. Roman | Energy Density-Flux Correlations in an Unusual Quantum State and in the
Vacuum | 21 pages, 7 figures; published version with typos corrected and one
added reference | Phys. Rev. D76 (2007) 064012 | 10.1103/PhysRevD.76.064012 | null | quant-ph gr-qc hep-th | null | In this paper we consider the question of the degree to which negative and
positive energy are intertwined. We examine in more detail a previously studied
quantum state of the massless minimally coupled scalar field, which we call a
``Helfer state''. This is a state in which the energy density can be made
arbitrarily negative over an arbitrarily large region of space, but only at one
instant in time. In the Helfer state, the negative energy density is
accompanied by rapidly time-varying energy fluxes. It is the latter feature
which allows the quantum inequalities, bounds which restrict the magnitude and
duration of negative energy, to hold for this class of states. An observer who
initially passes through the negative energy region will quickly encounter
fluxes of positive energy which subsequently enter the region. We examine in
detail the correlation between the energy density and flux in the Helfer state
in terms of their expectation values. We then study the correlation function
between energy density and flux in the Minkowski vacuum state, for a massless
minimally coupled scalar field in both two and four dimensions. In this latter
analysis we examine correlation functions rather than expectation values.
Remarkably, we see qualitatively similar behavior to that in the Helfer state.
More specifically, an initial negative energy vacuum fluctuation in some region
of space is correlated with a subsequent flux fluctuation of positive energy
into the region. We speculate that the mechanism which ensures that the quantum
inequalities hold in the Helfer state, as well as in other quantum states
associated with negative energy, is, at least in some sense, already
``encoded'' in the fluctuations of the vacuum.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 18:56:59 GMT"
},
{
"version": "v2",
"created": "Fri, 19 Oct 2007 01:01:48 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ford",
"L. H.",
""
],
[
"Roman",
"Thomas A.",
""
]
] |
0706.1971 | Nigel Cundy Dr | Nigel Cundy | Low-lying Wilson Dirac operator eigenvector mixing in dynamical overlap
Hybrid Monte-Carlo | 20 Pages, 4 figures; v2 with minor modifications; v3 further minor
modifications, as accepted by Computer Physics Communications | Comput.Phys.Commun.180:180-191,2009 | 10.1016/j.cpc.2008.09.007 | null | hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Current dynamical overlap fermion hybrid Monte Carlo simulations encounter
large fermionic forces when there is mixing between near zero-eigenvectors of
the kernel operator. This leads to low acceptance rates when there is a large
density of near zero eigenvectors. I present a method where these large forces
are eliminated and the large action jumps seen when two eigenvectors approach
zero are significantly reduced. This significantly increases the stability of
the algorithm, and allows the use of larger integration time steps.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 19:03:40 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Jul 2007 15:20:29 GMT"
},
{
"version": "v3",
"created": "Thu, 18 Dec 2008 16:48:14 GMT"
}
] | 2009-03-12T00:00:00 | [
[
"Cundy",
"Nigel",
""
]
] |
0706.1972 | Bhavtosh Bansal | Bhavtosh Bansal, M. Hayne, M. Geller, D. Bimberg, V. V. Moshchalkov | Excitonic Mott transition in type-II quantum dots | 4 figures | null | 10.1103/PhysRevB.77.241304 | null | cond-mat.other | null | Photoluminescence spectra measured on a type-II GaSb/GaAs quantum dot
ensemble at high excitation power indicate a Mott transition from the low
density state comprising of spatially-indirect excitons to a high density
electron-plasma state. Under the influence of a very high magnetic field, the
electron-plasma that is formed at high excitation powers is `frozen-out' into a
state of optically inactive magneto-excitons.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 19:11:46 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bansal",
"Bhavtosh",
""
],
[
"Hayne",
"M.",
""
],
[
"Geller",
"M.",
""
],
[
"Bimberg",
"D.",
""
],
[
"Moshchalkov",
"V. V.",
""
]
] |
0706.1973 | Dragomir Z. Djokovic | Dragomir Z. Djokovic | Skew-Hadamard matrices of orders 436, 580 and 988 exist | 12 pages, no figures | J, Combin. Designs 16 (2008), 493-498 | null | null | math.CO | null | We construct two difference families on each of the cyclic groups of order
109, 145 and 247, and use them to construct skew-Hadamard matrices of orders
436, 580 and 988. Such difference families and matrices are constructed here
for the first time. The matrices are constructed by using the Goethals-Seidel
array.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 19:21:55 GMT"
}
] | 2009-03-18T00:00:00 | [
[
"Djokovic",
"Dragomir Z.",
""
]
] |
0706.1974 | Claude Ederer | Claude Ederer, Nicola A. Spaldin | Towards a microscopic theory of toroidal moments in bulk periodic
crystals | replaced with final (published) version, which includes some changes
in the text to improve the clarity of presentation | Phys. Rev. B 76, 214404 (2007) | 10.1103/PhysRevB.76.214404 | null | cond-mat.str-el cond-mat.mtrl-sci | null | We present a theoretical analysis of magnetic toroidal moments in periodic
systems, in the limit in which the toroidal moments are caused by a time and
space reversal symmetry breaking arrangement of localized magnetic dipole
moments. We summarize the basic definitions for finite systems and address the
question of how to generalize these definitions to the bulk periodic case. We
define the toroidization as the toroidal moment per unit cell volume, and we
show that periodic boundary conditions lead to a multivaluedness of the
toroidization, which suggests that only differences in toroidization are
meaningful observable quantities. Our analysis bears strong analogy to the
modern theory of electric polarization in bulk periodic systems, but we also
point out some important differences between the two cases. We then discuss the
instructive example of a one-dimensional chain of magnetic moments, and we show
how to properly calculate changes of the toroidization for this system.
Finally, we evaluate and discuss the toroidization (in the local dipole limit)
of four important example materials: BaNiF_4, LiCoPO_4, GaFeO_3, and BiFeO_3.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 19:56:49 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Jun 2008 17:27:40 GMT"
}
] | 2008-06-03T00:00:00 | [
[
"Ederer",
"Claude",
""
],
[
"Spaldin",
"Nicola A.",
""
]
] |
0706.1975 | Katherine Vieira | Katherine Vieira, Dana I. Casetti-Dinescu, Rene A. Mendez, R. Michael
Rich, Terrence M. Girard, Vladimir I. Korchagin, William van Altena, Steven
R. Majewski, Sidney van den Bergh | Proper Motions in the Galactic Bulge: Plaut's Window | Submitted to AJ April 17th 2007. Accepted June 8th 2007. 45 pages, 14
figures | Astron.J.134:1432-1446,2007 | 10.1086/520813 | null | astro-ph | null | A proper motion study of a field of 20' x 20' inside Plaut's low extinction
window (l,b)=(0 deg,-8 deg), has been completed. Relative proper motions and
photographic BV photometry have been derived for ~21,000 stars reaching to
V~20.5 mag, based on the astrometric reduction of 43 photographic plates,
spanning over 21 years of epoch difference. Proper motion errors are typically
1 mas/yr and field dependent systematics are below 0.2 mas/yr.
Cross-referencing with the 2MASS catalog yielded a sample of ~8,700 stars, from
which predominantly disk and bulge subsamples were selected photometrically
from the JH color-magnitude diagram. The two samples exhibited different
proper-motion distributions, with the disk displaying the expected reflex solar
motion as a function of magnitude. Galactic rotation was also detected for
stars between ~2 and ~3 kpc from us. The bulge sample, represented by red
giants, has an intrinsic proper motion dispersion of (sigma_l,sigma_b)=(3.39,
2.91)+/-(0.11,0.09) mas/yr, which is in good agreement with previous results,
and indicates a velocity anisotropy consistent with either rotational
broadening or tri-axiality. A mean distance of 6.37^{+0.87}_{-0.77} kpc has
been estimated for the bulge sample, based on the observed K magnitude of the
horizontal branch red clump. The metallicity [M/H] distribution was also
obtained for a subsample of 60 bulge giants stars, based on calibrated
photometric indices. The observed [M/H] shows a peak value at [M/H]~-0.1 with
an extended metal poor tail and around 30% of the stars with supersolar
metallicity. No change in proper motion dispersion was observed as a function
of [M/H]. We are currently in the process of obtaining CCD UBVRI photometry for
the entire proper-motion sample of ~21,000 stars.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 20:00:05 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Vieira",
"Katherine",
""
],
[
"Casetti-Dinescu",
"Dana I.",
""
],
[
"Mendez",
"Rene A.",
""
],
[
"Rich",
"R. Michael",
""
],
[
"Girard",
"Terrence M.",
""
],
[
"Korchagin",
"Vladimir I.",
""
],
[
"van Altena",
"William",
""
],
[
"Majewski",
"Steven R.",
""
],
[
"Bergh",
"Sidney van den",
""
]
] |
0706.1976 | Gianfranco Gentile | G. Gentile, B. Famaey, F. Combes, P. Kroupa, H. S. Zhao, O. Tiret | Tidal dwarf galaxies as a test of fundamental physics | Accepted for publication in A&A Letters, 5 pages, 3 figures | Astron.Astrophys. 472 (2007) L25-L28 | 10.1051/0004-6361:20078081 | null | astro-ph | null | Within the cold dark matter (CDM) framework tidal dwarf galaxies (TDGs)
cannot contain dark matter, so the recent results by Bournaud et al. (2007)
that 3 rotating TDGs do show significant evidence for being dark matter
dominated is inconsistent with the current concordance cosmological theory
unless yet another dark matter component is postulated. We confirm that the TDG
rotation curves are consistent with Newtonian dynamics only if either an
additional dark matter component is postulated, or if all 3 TDGs happen to be
viewed nearly edge-on, which is unlikely given the geometry of the tidal
debris. We also find that the observed rotation curves are very naturally
explained without any free parameters within the modified Newtonian dynamics
(MOND) framework if inclinations are adopted as derived by Bournaud et al. We
explore different inclination angles and two different assumptions about the
external field effect. The results do not change significantly, and we conclude
therefore that Newtonian dynamics has severe problems while MOND does
exceedingly well in explaining the observed rotation curves of the 3 TDGs
studied by Bournaud et al.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 14:44:20 GMT"
},
{
"version": "v2",
"created": "Thu, 12 Jul 2007 17:02:41 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gentile",
"G.",
""
],
[
"Famaey",
"B.",
""
],
[
"Combes",
"F.",
""
],
[
"Kroupa",
"P.",
""
],
[
"Zhao",
"H. S.",
""
],
[
"Tiret",
"O.",
""
]
] |
0706.1977 | Nemanja Kaloper | Nemanja Kaloper | Challenging the Cosmological Constant | 13 pages, 1 .eps figure, added references and comments | Phys.Lett.B653:109-115,2007 | 10.1016/j.physletb.2007.07.061 | null | astro-ph gr-qc hep-ph hep-th | null | We outline a dynamical dark energy scenario whose signatures may be
simultaneously tested by astronomical observations and laboratory experiments.
The dark energy is a field with slightly sub-gravitational couplings to matter,
a logarithmic self-interaction potential with a scale tuned to $\sim 10^{-3}
{\rm eV}$, as is usual in quintessence models, and an effective mass $m_\phi$
influenced by the environmental energy density. Its forces may be suppressed
just below the current bounds by the chameleon-like mimicry, whereby only outer
layers of mass distributions, of thickness $1/m_\phi$, give off appreciable
long range forces. After inflation and reheating, the field is relativistic,
and attains a Planckian expectation value before Hubble friction freezes it.
This can make gravity in space slightly stronger than on Earth. During the
matter era, interactions with nonrelativistic matter dig a minimum close to the
Planck scale. However, due to its sub-gravitational matter couplings the field
will linger away from this minimum until the matter energy density dips below
$\sim 10^{-12} {\rm eV}^4$. Then it starts to roll to the minimum, driving a
period of cosmic acceleration. Among the signatures of this scenario may be
dark energy equation of state $w \ne -1$, stronger gravity in dilute mediums,
that may influence BBN and appear as an excess of dark matter, and
sub-millimeter corrections to Newton's law, close to the present laboratory
limits.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 19:59:32 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 23:11:38 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Kaloper",
"Nemanja",
""
]
] |
0706.1978 | Francesco Paparella | Anna Maria Cherubini, Giorgio Metafune, Francesco Paparella | On the Stopping Time of a Bouncing Ball | Submitted to archive for rational mechanics and analysis | null | null | null | math-ph math.MP | null | We study a simple model of a bouncing ball that takes explicitely into
account the elastic deformability of the body and the energy dissipation due to
internal friction. We show that this model is not subject to the problem of
inelastic collapse, that is, it does not allow an infinite number of impacts in
a finite time. We compute asymptotic expressions for the time of flight and for
the impact velocity. We also prove that contacts with zero velocity of the
lower end of the ball are possible, but non-generic. Finally, we compare our
findings with other models and laboratory experiments.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 20:04:06 GMT"
}
] | 2007-06-15T00:00:00 | [
[
"Cherubini",
"Anna Maria",
""
],
[
"Metafune",
"Giorgio",
""
],
[
"Paparella",
"Francesco",
""
]
] |
0706.1979 | Jacobo Diaz Polo | Jacobo Diaz-Polo and Enrique Fernandez-Borja | Black hole radiation spectrum in LQG: Isolated Horizon framework | 6 pages, 2 figures; version to appear in Classical and Quantum
Gravity | Class.Quant.Grav.25:105007,2008 | 10.1088/0264-9381/25/10/105007 | null | gr-qc | null | Recent detailed analysis within the Loop Quantum Gravity calculation of black
hole entropy shows a stair-like structure in the behavior of entropy as a
function of horizon area. The non-trivial distribution of the degeneracy of the
black hole horizon area eigenstates is at the origin of this behavior. This
degeneracy distribution is analyzed and a phenomenological model is put forward
to study the implications of this distribution in the black hole radiation
spectrum. Some qualitative quantum effects are obtained within the isolated
horizon framework. This result provides us with a possible observational test
of this model for quantum black holes.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 18:30:06 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Apr 2008 11:41:02 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Diaz-Polo",
"Jacobo",
""
],
[
"Fernandez-Borja",
"Enrique",
""
]
] |
0706.1980 | Oriol Pujolas | Keisuke Izumi, Kazuya Koyama, Oriol Pujolas and Takahiro Tanaka | Bubbles in the Self-Accelerating Universe | 8 pages, 5 figures | Phys.Rev.D76:104041,2007 | 10.1103/PhysRevD.76.104041 | null | hep-th astro-ph gr-qc | null | We revisit the issue of the stability in the Dvali-Gabadadze-Porrati model,
by considering the nucleation of bubbles of the conventional branch within the
self-accelerating branch. We construct an instanton describing this process in
the thin wall approximation. On one side of the bubble wall, the bulk consists
of the exterior of the brane while on the other side it is the interior. The
solution requires the presence of a 2-brane (the bubble wall) which induces the
transition. However, we show that this instanton cannot be realized as the thin
wall limit of any smooth solution. Once the bubble thickness is resolved, the
equations of motion do not allow O(4) symmetric solutions joining the two
branches. We conclude that the thin wall instanton is unphysical, and that one
cannot have processes connecting the two branches, unless negative tension
bubble walls are introduced. This also suggests that the self-accelerating
branch does not decay into the conventional branch nucleating bubbles. We
comment on other kinds of bubbles that could interpolate between the two
branches.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 20:10:12 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Izumi",
"Keisuke",
""
],
[
"Koyama",
"Kazuya",
""
],
[
"Pujolas",
"Oriol",
""
],
[
"Tanaka",
"Takahiro",
""
]
] |
0706.1981 | Georgii Alekseev | G.A. Alekseev and V.A. Belinski | Equilibrium configurations of two charged masses in General Relativity | 4 pages; accepted for publication in Phys. Rev. D | Phys.Rev.D76:021501,2007 | 10.1103/PhysRevD.76.021501 | null | gr-qc hep-th | null | An asymptotically flat static solution of Einstein-Maxwell equations which
describes the field of two non-extreme Reissner - Nordstr\"om sources in
equilibrium is presented. It is expressed in terms of physical parameters of
the sources (their masses, charges and separating distance). Very simple
analytical forms were found for the solution as well as for the equilibrium
condition which guarantees the absence of any struts on the symmetry axis. This
condition shows that the equilibrium is not possible for two black holes or for
two naked singularities. However, in the case when one of the sources is a
black hole and another one is a naked singularity, the equilibrium is possible
at some distance separating the sources. It is interesting that for
appropriately chosen parameters even a Schwarzschild black hole together with a
naked singularity can be "suspended" freely in the superposition of their
fields.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 20:21:31 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Alekseev",
"G. A.",
""
],
[
"Belinski",
"V. A.",
""
]
] |
0706.1982 | Brian Powell | Brian A. Powell, William H. Kinney | Limits on primordial power spectrum resolution: An inflationary flow
analysis | 10 pages, 4 figures. The flow code used in this paper is available at
http://www.physics.buffalo.edu/whkinney/flowcode. References added, version
accepted by JCAP | JCAP 0708:006,2007 | 10.1088/1475-7516/2007/08/006 | null | astro-ph | null | We investigate the ability of current CMB data to reliably constrain the form
of the primordial power spectrum generated during inflation. We attempt to
identify more exotic power spectra that yield equally good fits to the data as
simple power-law spectra. In order to test a wide variety of spectral shapes,
we combine the flow formalism, which is a method of stochastic model
generation, with a numerical integration of the mode equations of quantum
fluctuations. This allows us to handle inflation models that yield spectra that
are not well described by the standard spectral parameterization. Using the
latest WMAP data-set, we find a high degree of variation in possible spectral
shapes. In particular, we find strongly running spectra arising from
fast-rolling inflaton fields providing equally good fits to the data as
power-law spectra arising from slowly-rolling fields. Current data poorly
constrains the spectrum on scales (k < 0.01 h{\rm Mpc}^{-1}), where the error
due to cosmic variance is large. Among the statistically degenerate models, we
identify spectra with strong running on these larger scales, but with reduced
running at smaller scales. These models predict values for the tensor-to-scalar
ratio, (r), that lie outside the 2-(\sigma) confidence interval obtained from
SDSS+WMAP data for spectra that are parametrized as power-laws or spectra with
constant running. By considering more generalized power spectra, we therefore
open up regions of parameter space excluded for simpler models.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 15:50:57 GMT"
},
{
"version": "v2",
"created": "Thu, 9 Aug 2007 15:14:32 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Powell",
"Brian A.",
""
],
[
"Kinney",
"William H.",
""
]
] |
0706.1983 | Nathan Grau | N. Grau (for the ATLAS Collaboration) | The Heavy Ion Physics Program with ATLAS at the LHC | 8 pages, 6 figures, prepared for the 23rd Winter Workshop on Nuclear
Dynamics, Big Sky, MT, Feb 11-18, 2007 | null | null | null | nucl-ex | null | The first Pb+Pb collisions at the Large Hadron Collider (LHC) at sqrts_NN =
5.52 TeV are imminent. Heavy ion collisions at the LHC provide an extended
energy lever arm to the existing measurements made at RHIC and SPS, especially
in hard (large-Q^2) processes. In this contribution an overview of the ATLAS
detector is given and the current physics focus of Heavy Ion Working Group is
discussed.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 20:27:12 GMT"
}
] | 2007-06-15T00:00:00 | [
[
"Grau",
"N.",
"",
"for the ATLAS Collaboration"
]
] |
0706.1984 | Ulrich Husemann | Ulrich Husemann (the CDF and D0 Collaborations) | Measurements of Top Properties at the Tevatron | 4 pages, 3 figures, to appear in Proc. 42th Rencontres de Moriond:
QCD and Hadronic Interactions, La Thuile, Italy, March 17-24, 2007 | null | null | FERMILAB-CONF-07-209-E | hep-ex | null | The large data samples of thousands of top events collected at the Tevatron
experiments CDF and D0 allow for a variety of measurements to analyze the
properties of the top quark. Guided by the question "Is the top quark observed
at the Tevatron really the top quark of the standard model,'' we present
Tevatron analyses studying the top production mechanism including resonant
$t\bar{t}$ production, the V-A structure of the $t\to Wb$ decay vertex, the
charge of the top quark, and single-top production via flavor-changing neutral
currents.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 20:29:13 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Husemann",
"Ulrich",
"",
"the CDF and D0 Collaborations"
]
] |
0706.1985 | Jim Crumley | James P. Crumley, Ari D. Palczewski, Stephen A. Kaster | Examining the Location of the Magnetopause in an Undergraduate Lab | LaTeX, 9 pages, 5 figures. Fixed date format and bibliography.
Resubmitted to the American Journal of Physics following referees comments.
Added section on Development and Evolution of Lab | null | null | null | physics.space-ph physics.ed-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Integrating areas of current research into undergraduate physics labs can be
a difficult task. The location of the magnetopause is one problem that can be
examined with no prior exposure to space physics. The magnetopause location can
be viewed as a pressure balance between the dynamic pressure of the solar wind
and the magnetic pressure of the magnetosphere. In this lab sophomore and
junior students examine the magnetopause location using simulation results from
BATS-R-US global MHD code run at NASA's Community Coordinated Modeling Center.
Students also analyze data from several spacecraft to find magnetopause
crossings. The students get reasonable agreement between their results and
model predictions from this lab as well as exposure to the tools and techniques
of space physics.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 14:37:41 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Sep 2015 19:11:28 GMT"
}
] | 2015-09-21T00:00:00 | [
[
"Crumley",
"James P.",
""
],
[
"Palczewski",
"Ari D.",
""
],
[
"Kaster",
"Stephen A.",
""
]
] |
0706.1986 | Julia E. Medvedeva | J.E. Medvedeva, E.N. Teasley, M.D. Hoffman | Electronic band structure and carrier effective mass in calcium
aluminates | null | null | 10.1103/PhysRevB.76.155107 | null | cond-mat.mtrl-sci | null | First-principles electronic band structure investigations of five compounds
of the CaO-Al2O3 family, 3CaO.Al2O3, 12CaO.7Al2O3, CaO.Al2O3, CaO.2Al2O3 and
CaO.6Al2O3, as well as CaO and alpha-, theta- and kappa-Al2O3 are performed. We
find that the conduction band in the complex oxides is formed from the oxygen
antibonding p-states and, although the band gap in Al2O3 is almost twice larger
than in CaO, the s-states of both cations. Such a hybrid nature of the
conduction band leads to isotropic electron effective masses which are nearly
the same for all compounds investigated. This insensitivity of the effective
mass to variations in the composition and structure suggests that upon a proper
degenerate doping, both amorphous and crystalline phases of the materials will
possess mobile extra electrons.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 20:41:48 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Medvedeva",
"J. E.",
""
],
[
"Teasley",
"E. N.",
""
],
[
"Hoffman",
"M. D.",
""
]
] |
0706.1987 | Alfred de Wijn | A. G. de Wijn, R. J. Rutten, T. D. Tarbell | Dynamics of the solar chromosphere. V. High-frequency modulation in
ultraviolet image sequences from TRACE | 9 pages, 8 figures | Astron.Astrophys.430:1119-1127,2005 | 10.1051/0004-6361:20041727 | null | astro-ph | null | We search for signatures of high-frequency oscillations in the upper solar
photosphere and low chromosphere in the context of acoustic heating of outer
stellar atmospheres. We use ultraviolet image sequences of a quiet center-disk
area from the Transition Region and Coronal Explorer (TRACE) mission which were
taken with strict cadence regularity. The latter permits more reliable
high-frequency diagnosis than in earlier work. Spatial Fourier power maps,
spatially averaged coherence and phase-difference spectra, and spatio-temporal
k-f decompositions all contain high-frequency features that at first sight seem
of considerable intrinsic interest but actually are more likely to represent
artifacts of different nature. Spatially averaged phase difference measurement
provides the most sensitive diagnostic and indicates the presence of acoustic
modulation up to f=20 mHz (periods down to 50 seconds) in internetwork areas.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:54:33 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"de Wijn",
"A. G.",
""
],
[
"Rutten",
"R. J.",
""
],
[
"Tarbell",
"T. D.",
""
]
] |
0706.1988 | Luis Anchordoqui | Luis A. Anchordoqui | Lectures on Astronomy, Astrophysics, and Cosmology | Based on lectures given at Lehman College, City University of New
York, Spring 2016. arXiv admin note: text overlap with arXiv:0907.5424,
arXiv:astro-ph/9702042, arXiv:hep-ph/9602260, arXiv:1308.5347 by other
authors | null | null | null | physics.ed-ph astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This is a written version of a series of lectures aimed at undergraduate
students in astrophysics/particle theory/particle experiment. We summarize the
important progress made in recent years towards understanding high energy
astrophysical processes and we survey the state of the art regarding the
concordance model of cosmology.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 12:41:54 GMT"
},
{
"version": "v2",
"created": "Wed, 29 Aug 2007 00:25:02 GMT"
},
{
"version": "v3",
"created": "Wed, 15 Jun 2016 14:00:56 GMT"
}
] | 2016-06-16T00:00:00 | [
[
"Anchordoqui",
"Luis A.",
""
]
] |
0706.1989 | Anna Grodecka | A. Grodecka, C. Weber, P. Machnikowski, A. Knorr | Interplay and optimization of decoherence mechanisms in the optical
control of spin quantum bits implemented on a semiconductor quantum dot | Final version, 14 pages, 11 figures | Phys. Rev. B 76, 205305 (2007) | 10.1103/PhysRevB.76.205305 | null | cond-mat.mes-hall quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the influence of the environment on an optically induced rotation of
a single electron spin in a charged semiconductor quantum dot. We analyze the
decoherence mechanisms resulting from the dynamical lattice response to the
charge evolution induced in a trion-based optical spin control scheme.
Moreover, we study the effect of the finite trion lifetime and of the
imperfections of the unitary evolution such as off-resonant excitations and the
nonadiabaticity of the driving. We calculate the total error of the operation
on a spin-based qubit in an InAs/GaAs quantum dot system and discuss possible
optimization against the different contributions. We indicate the parameters
which allow for coherent control of the spin with a single qubit gate error as
low as $10^{-4}$.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 20:57:26 GMT"
},
{
"version": "v2",
"created": "Mon, 27 Apr 2009 12:17:29 GMT"
}
] | 2009-04-27T00:00:00 | [
[
"Grodecka",
"A.",
""
],
[
"Weber",
"C.",
""
],
[
"Machnikowski",
"P.",
""
],
[
"Knorr",
"A.",
""
]
] |
0706.1990 | Fabian Schmidt | Fabian Schmidt, Maximo Ave, Lorenzo Cazon, Aaron Chou | Applying Extensive Air Shower Universality to Ground Detector Data | Proceedings of the 30th International Cosmic Ray Conference, Merida,
Mexico; 4 pages, 4 figures | null | null | ICRC contrib. no. 752 | astro-ph hep-ex | null | Air shower universality states that the electromagnetic part of
hadron-induced extensive air showers (EAS) can be completely described in terms
of the primary energy and shower age. In addition, simulations show that the
muon part is well characterized by an overall normalization which depends on
the primary particle and hadronic interaction model. We investigate the
consequences of EAS universality for ground arrays, which sample EAS at large
core distances, and show how universality can be used to experimentally
determine the muon content as well as the primary energy of cosmic ray air
showers in a model-independent way.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 21:04:00 GMT"
},
{
"version": "v2",
"created": "Sun, 15 Jul 2007 03:05:16 GMT"
}
] | 2007-07-15T00:00:00 | [
[
"Schmidt",
"Fabian",
""
],
[
"Ave",
"Maximo",
""
],
[
"Cazon",
"Lorenzo",
""
],
[
"Chou",
"Aaron",
""
]
] |
0706.1991 | Razvan Radulescu M.D. | Razvan Tudor Radulescu and Kai Kehe | Antiproliferative MCR peptides block physical interaction of insulin
with retinoblastoma protein (RB) in human lung cancer cells | 12 pages, 3 figures | null | null | null | q-bio.SC q-bio.BM | null | Fifteen years ago, a structural analysis of the hormone insulin and the
retinoblastoma tumor suppressor protein (RB) revealed that they may physically
interact with one another. Subsequently, an RB peptide corresponding to the
proposed RB binding site for insulin was found to recognize full-length insulin
in vitro. As part of efforts aimed at developing this RB peptide into an
anti-cancer drug, this molecule was chemically coupled to a cellular
internalization signal and termed "MCR peptide". Meanwhile, several such MCR
peptide variants have been demonstrated to restrain the proliferation of
different human cancer cells in vitro and in vivo. Moreover, one of the MCR
peptides coined MCR-10 was shown to be capable of interfering with the complex
formation between insulin and RB in HepG2 human hepatoma cells, as monitored by
immunofluorescence. This latter result indicating an in vivo association
between insulin and RB was confirmed by a follow-up study combining the methods
of co-immunoprecipitation and immunoblotting. Here, we provide evidence for the
existence of the insulin-RB complex in A549 human non-small cell lung cancer
cells. Specifically, we demonstrate this heterodimer by means of a magnetic
beads-based immunoprecipitation approach and equally show that this dimer can
be disrupted by MCR-4 or MCR-10 each of which is known to possess
antiproliferative properties, yet to a much lesser extent by a control peptide.
Thus, this investigation has yielded another important proof for the occurrence
of the insulin-RB dimer and, furthermore, its validity as a target for
antineoplastic MCR peptides.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 20:58:29 GMT"
}
] | 2007-06-15T00:00:00 | [
[
"Radulescu",
"Razvan Tudor",
""
],
[
"Kehe",
"Kai",
""
]
] |
0706.1992 | Jignesh Pandya | J N Pandya, Ajay Kumar Rai, P C Vinodkumar | Masses and decay modes of charmonia using a confinement model | Submitted to AIP for proceedings of International Workshop on
Theoretical High Energy Physics held at IIT Roorkee, INDIA during 15-20
March, 2007 | AIPConf.Proc.939:20-23,2007 | 10.1063/1.2803781 | null | hep-ph | null | The masses of charmonium s and p-states, pseudoscalar and vector decay
constants, leptonic, hadronic as well as radiative decay widths for charmonia
have been computed in the framework of extended harmonic confinement model
without any additional parameters. The outcome in comparison with other
contemporary theoretical and experimental results is presented.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 17:15:37 GMT"
},
{
"version": "v2",
"created": "Fri, 6 Jul 2007 05:35:15 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Pandya",
"J N",
""
],
[
"Rai",
"Ajay Kumar",
""
],
[
"Vinodkumar",
"P C",
""
]
] |
0706.1993 | Krzysztof Burdzy | Richard F. Bass, Krzysztof Burdzy | On pathwise uniqueness for reflecting Brownian motion in $C^{1+\gamma}$
domains | Published in at http://dx.doi.org/10.1214/08-AOP390 the Annals of
Probability (http://www.imstat.org/aop/) by the Institute of Mathematical
Statistics (http://www.imstat.org) | Annals of Probability 2008, Vol. 36, No. 6, 2311-2331 | 10.1214/08-AOP390 | IMS-AOP-AOP390 | math.PR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Pathwise uniqueness holds for the Skorokhod stochastic differential equation
in $C^{1+\gamma}$ domains in $\mathbb{R}^d$ for $\gamma >1/2$ and $d\geq3$.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 21:11:37 GMT"
},
{
"version": "v2",
"created": "Tue, 20 Jan 2009 14:27:46 GMT"
}
] | 2009-01-20T00:00:00 | [
[
"Bass",
"Richard F.",
""
],
[
"Burdzy",
"Krzysztof",
""
]
] |
0706.1994 | Gavin E. Crooks | Gavin E. Crooks | On the Quantum Jarzynski Identity | 4 pages | J. Stat. Mech.: Theor. Exp. P10023 (9pp) (2008) | 10.1088/1742-5468/2008/10/P10023 | null | cond-mat.stat-mech quant-ph | null | In this note, we will discuss how to compactly express and prove the
Jarzynski identity for an open quantum system with dissipative dynamics. We
will avoid explicitly measuring the work directly, which is tantamount to
continuously monitoring the system, and instead measure the heat flow from the
environment. We represent the measurement of heat flow with Hermitian map
superoperators that act on the system density matrix. Hermitian maps provide a
convenient and compact representation of sequential measurement and correlation
functions.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 21:30:07 GMT"
}
] | 2008-11-07T00:00:00 | [
[
"Crooks",
"Gavin E.",
""
]
] |
0706.1995 | William Harris | W.E.Harris, G.L.H.Harris, A.C.Layden, E.H.Wehner | The Leo Elliptical NGC 3379: A Metal-Poor Halo Emerges | 48 pages, 15 figures. Complete preprint file available at
http://physwww.mcmaster.ca/%7Eharris/Publications.html. to be published in
Ap.J. 667, Oct 1 (2007) | Astrophys.J.666:903-918,2007 | 10.1086/520799 | null | astro-ph | null | We have used the ACS camera on HST to obtain (V,I) photometry for 5300
red-giant stars in the halo of the dominant Leo-group member NGC 3379, a galaxy
usually regarded as a classic normal giant elliptical. We use this sample of
stars to derive the metallicity distribution function (MDF) for its outer-halo
field stars 33 kpc from the galaxy center. The MDF is distinctly unlike all the
other E galaxies for which we have similar data (including the Local Group
dwarf ellipticals, the intermediate-luminosity NGC 3377, and the giant NGC
5128). First, the MDF for the NGC 3379 outer halo is broad and flat, with many
stars at every interval in [m/H]. Second, we see a metallicity gradient across
our ACS field such that in its outermost region the blue, low-metallicity stars
([m/H] < -0.7) are beginning to dominate and the higher-metallicity stars are
rapidly diminishing. Our target field is centered at a projected distance about
equal to 12 R_e, twice as far out in units of effective radius as in any of the
other galaxies that we have surveyed. If NGC 3379 is indeed representative of
large E/S0 galaxies, we predict that such galaxies in general will reveal
diffuse low-metallicity subpopulations, but that photometry at radii r ~ 10 -
15 R_e will be necessary to see the faint low-metallicity component clearly.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 21:29:08 GMT"
}
] | 2011-02-11T00:00:00 | [
[
"Harris",
"W. E.",
""
],
[
"Harris",
"G. L. H.",
""
],
[
"Layden",
"A. C.",
""
],
[
"Wehner",
"E. H.",
""
]
] |
0706.1996 | Razvan Radulescu M.D. | Razvan Tudor Radulescu | Planet RB: a personal contribution to a proteomic map of human
retinoblastoma protein | 4 pages, 1 table | null | null | null | q-bio.BM q-bio.SC | null | As I compress on the canvas of a few pages here major results of my research
on the retinoblastoma tumor suppressor protein (RB) spreading over the past 15
years, an exciting picture emerges on this unique host molecule which surpasses
in its complexity even that of the most capable viral proteins known to date.
Accordingly, RB has the potential to bind not only growth-promoting proteins
such as insulin, but also to attach itself to calcium and oxygen, as well as to
be secreted into the extracellular environment. Moreover, RB may exert
proteolytic, antimicrobial and anti-aging activities. These condensed
structure-based insights on RB are the substance of a scientific revolution I
have initiated a long time ago, yet likely to gain even further speed in the
years to come, thus expanding both our understanding of life at the molecular
level and the possibilities for pharmacological modulation of fundamental
biological phenomena, particularly in oncology and gerontology.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 21:34:04 GMT"
}
] | 2007-06-15T00:00:00 | [
[
"Radulescu",
"Razvan Tudor",
""
]
] |
0706.1997 | William Harris | W.E.Harris, G.L.H.Harris, A.C.Layden, P.B.Stetson | HST Photometry for the Halo Stars in the Leo Elliptical NGC 3377 | 40 pages, 17 figures | Astron.J.134:43-55,2007 | 10.1086/518233 | null | astro-ph | null | We have used the ACS camera on HST to obtain (V,I) photometry for 57,000
red-giant stars in the halo of the Leo elliptical NGC 3377. We use this sample
of stars to derive the metallicity distribution function (MDF) for its halo
field stars, and comment on its chemical evolution history compared with both
larger and smaller E galaxies. Our ACS/WFC field spans a radial range extending
from 4 to 18 kpc projected distance from the center of NGC 3377 and thus covers
a significant portion of this galaxy's halo. We find that the MDF is broad,
reaching a peak at [m/H] ~ -0.6$, but containing virtually no stars more
metal-poor than log [m/H] = -1.5$. It may, in addition, have relatively few
stars more metal-rich than [m/H] = -0.3$, although interpretation of the
high-metallicity end of the MDF is limited by photometric completeness that
affects the detection of the reddest, most metal-rich stars. NGC 3377 appears
to have an enrichment history intermediate between those of normal dwarf
ellipticals and the much larger giants. As yet, we find no clear evidence that
the halo of NGC 3377 contains a significant population of ``young'' (< 3 Gy)
stars.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 21:51:07 GMT"
}
] | 2010-11-05T00:00:00 | [
[
"Harris",
"W. E.",
""
],
[
"Harris",
"G. L. H.",
""
],
[
"Layden",
"A. C.",
""
],
[
"Stetson",
"P. B.",
""
]
] |
0706.1998 | Nayana Shah | N. Shah, C. J. Bolech | Proposal for a two-channel quantum dot setup: Prediction for the
capacitance lineshape | Proceedings for SCES conference (2005) | Physica B 378, 951 (2006) | 10.1016/j.physb.2006.01.363 | null | cond-mat.mes-hall cond-mat.str-el | null | We have made a detailed proposal for a two-channel quantum dot setup. The
energy scales in the problem are such that we are able to make connection with
the two-channel Anderson model, which, in spite of being well-known in the
context of heavy-Fermion systems remained theoretically elusive until recently
and lacked a mesoscopic realization. Verification of our precise and robust
predictions for the differential capacitance lineshape of the dot will provide
an experimental signature of the two-channel behavior.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 21:59:45 GMT"
}
] | 2007-06-17T00:00:00 | [
[
"Shah",
"N.",
""
],
[
"Bolech",
"C. J.",
""
]
] |
0706.1999 | Craig J. Hogan | Craig J. Hogan | Spacetime Indeterminacy and Holographic Noise | 13 pages, LaTex, 6 figures | null | null | null | gr-qc astro-ph hep-th | null | A new kind of quantum indeterminacy of transverse position is shown to arise
from quantum degrees of freedom of spacetime, based on the assumption that
classical trajectories can be defined no better than the diffraction limit of
Planck scale waves. Indeterminacy of the angular orientation of particle
trajectories due to wave/particle duality at the Planck scale leads to
indeterminacy of a nearly-flat spacetime metric, described as a small
nonvanishing quantum commutation relation between transverse position operators
at different events along a null trajectory. An independent derivation of the
same effect is presented based on the requirement of unitarity in black hole
evaporation. The indeterminacy is interpreted as a universal holographic
quantum spacetime noise, with a frequency-independent spectrum of metric
perturbation amplitude, h_H^2^{1/2} \simeq \sqrt{l_P}=2.3 \times 10^{-22}
/\sqrt{Hz}, where l_P denotes the Planck length. The effect is estimated to be
directly measurable using current interferometer technology similar to LIGO and
LISA.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:10:26 GMT"
},
{
"version": "v2",
"created": "Mon, 22 Oct 2007 22:00:23 GMT"
}
] | 2007-10-23T00:00:00 | [
[
"Hogan",
"Craig J.",
""
]
] |
0706.2000 | Mark S. Byrd | Mark S. Byrd and Gavin K. Brennen | General Depolarized Pure States: Identification and Properties | 1 figure, 9 pages, revtex4, slightly rewritten, reorganized, new
section | Physics Letters A, Vol. 372, 1770 (2008) | 10.1016/j.physleta.2007.10.074 | null | quant-ph | null | The Schmidt decomposition is an important tool in the study of quantum
systems especially for the quantification of the entanglement of pure states.
However, the Schmidt decomposition is only unique for bipartite pure states,
and some multipartite pure states. Here a generalized Schmidt decomposition is
given for states which are equivalent to depolarized pure states. Experimental
methods for the identification of this class of mixed states are provided and
some examples are discussed which show the utility of this description. A
particularly interesting example provides, for the first time, an
interpretation of the number of negative eigenvalues of the density matrix.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 18:24:55 GMT"
},
{
"version": "v2",
"created": "Wed, 30 Jan 2008 01:31:42 GMT"
}
] | 2009-02-04T00:00:00 | [
[
"Byrd",
"Mark S.",
""
],
[
"Brennen",
"Gavin K.",
""
]
] |
0706.2001 | Joshua M. Deutsch | J.M. Deutsch | Polymers in a vacuum | 4 pages, 3 figures, two column format | null | 10.1103/PhysRevLett.99.238301 | null | cond-mat.soft cond-mat.stat-mech | null | In a variety of situations, isolated polymer molecules are found in a vacuum
and here we examine their properties. Angular momentum conservation is shown to
significantly alter the average size of a chain and its conservation is only
broken slowly by thermal radiation. The time autocorrelation for monomer
position oscillates with a characteristic time proportional to chain length.
The oscillations and damping are analyzed in detail. Short range repulsive
interactions suppress oscillations and speed up relaxation but stretched chains
still show damped oscillatory time correlations.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:12:47 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Deutsch",
"J. M.",
""
]
] |
0706.2002 | Vesselin Gueorguiev | V. G. Gueorguiev, P. D. Kunz, J. E. Escher, F. S. Dietrich | Neutron Transfer Reactions for Deformed Nuclei Using Sturmian Basis | 12 pages (two columns), 13 figures (16 graphs), 3 tables, revtex4,
bibTeX, pdfTeX | null | null | UCRL-JRNL-231626 | nucl-th | null | We study the spin-parity distribution P(J$^{\pi}$,E) of $^{156}$Gd excited
states above the neutron separation energy that are expected to be populated
via the neutron pickup reaction $^{157}$Gd($^{3}$He,$^{4}$He)$^{156}$Gd. In
general, modeling of the spin-parity distribution is important for the
applicability of the surrogate reaction technique as a method of deducing
reaction cross sections. We model excited states in $^{156}$Gd as rotational
states built on intrinsic states consisting of a hole in the core where the
hole represents neutron removal form a deformed single particle state. The
reaction cross section to each excited state is calculated using standard
reaction code that uses spherical reaction form-factor input. The spectroscopic
factor associated with each form-factor is the expansion coefficient of the
deformed neutron state in a spherical Sturmian basis consisting of the
spherical reaction form-factors.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:17:39 GMT"
}
] | 2007-06-15T00:00:00 | [
[
"Gueorguiev",
"V. G.",
""
],
[
"Kunz",
"P. D.",
""
],
[
"Escher",
"J. E.",
""
],
[
"Dietrich",
"F. S.",
""
]
] |
0706.2003 | Joanne Mason | Joanne Mason, Fausto Cattaneo and Stanislav Boldyrev | Numerical Measurements of the Spectrum in Magnetohydrodynamic Turbulence | 4 pages, 2 figures | Phys.Rev.E77:036403,2008 | 10.1103/PhysRevE.77.036403 | null | astro-ph nlin.CD physics.flu-dyn physics.plasm-ph | null | We report the results of an extensive set of direct numerical simulations of
forced, incompressible, magnetohydrodynamic turbulence with a strong guide
field. The aim is to resolve the controversy regarding the power law exponent
(\alpha, say) of the field perpendicular energy spectrum E(k_\perp) \propto
k_\perp ^ {\alpha}. The two main theoretical predictions, \alpha=-3/2 and
\alpha=-5/3, have both received some support from numerical simulations carried
out by different groups. Our simulations have a resolution of 512^3 mesh
points, a strong guide field, an anisotropic simulation domain, and implement a
broad range of large-scale forcing routines, including those previously
reported in the literature. Our findings indicate that the spectrum of well
developed, strong incompressible MHD turbulence with a strong guide field is
E(k_{\perp})\propto k_{\perp}^{-3/2}.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:26:21 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Mason",
"Joanne",
""
],
[
"Cattaneo",
"Fausto",
""
],
[
"Boldyrev",
"Stanislav",
""
]
] |
0706.2004 | Alexander Balanov | A.G. Balanov, D.Fowler, A. Patan\`e, and L. Eaves, and T.M. Fromhold | Bifurcations and chaos in semiconductor superlattices with a tilted
magnetic field | 14 pages 11 figures | Phys. Rev. E 77, 026209 (2008) | 10.1103/PhysRevE.77.026209 | null | cond-mat.other | null | We study the effects of dissipation on electron transport in a semiconductor
superlattice with an applied bias voltage and a magnetic field that is tilted
relative to the superlattice axis.In previous work, we showed that although the
applied fields are stationary,they act like a THz plane wave, which strongly
couples the Bloch and cyclotron motion of electrons within the lowest miniband.
As a consequence,the electrons exhibit a unique type of Hamiltonian chaos,
which creates an intricate mesh of conduction channels (a stochastic web) in
phase space, leading to a large resonant increase in the current flow at
critical values of the applied voltage. This phase-space patterning provides a
sensitive mechanism for controlling electrical resistance. In this paper, we
investigate the effects of dissipation on the electron dynamics by modifying
the semiclassical equations of motion to include a linear damping term. We
demonstrate that even in the presence of dissipation,deterministic chaos plays
an important role in the electron transport process. We identify mechanisms for
the onset of chaos and explore the associated sequence of bifurcations in the
electron trajectories. When the Bloch and cyclotron frequencies are
commensurate, complex multistability phenomena occur in the system. In
particular, for fixed values of the control parameters several distinct stable
regimes can coexist, each corresponding to different initial conditions. We
show that this multistability has clear, experimentally-observable, signatures
in the electron transport characteristics.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:26:36 GMT"
},
{
"version": "v2",
"created": "Tue, 30 Oct 2007 14:59:30 GMT"
}
] | 2008-03-13T00:00:00 | [
[
"Balanov",
"A. G.",
""
],
[
"Fowler",
"D.",
""
],
[
"Patanè",
"A.",
""
],
[
"Eaves",
"L.",
""
],
[
"Fromhold",
"T. M.",
""
]
] |
0706.2005 | Koji Hashimoto | Minoru Eto, Koji Hashimoto and Seiji Terashima | QCD String as Vortex String in Seiberg-Dual Theory | 15 pages, 1 figure | JHEP 0709:036,2007 | 10.1088/1126-6708/2007/09/036 | null | hep-th | null | We construct a classical vortex string solution in a Seiberg-dual theory of
N=1 supersymmetric SO(N_c) QCD which flows to a confining phase. We claim that
this vortex string is a QCD string, as previouly argued by M.Strassler. In
SO(N_c) QCD, it is known that stable QCD strings exist even in the presence of
dynamical quarks. We show that our vortex strings are stable in the
Seiberg-dual theory.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 17:27:26 GMT"
}
] | 2009-04-30T00:00:00 | [
[
"Eto",
"Minoru",
""
],
[
"Hashimoto",
"Koji",
""
],
[
"Terashima",
"Seiji",
""
]
] |
0706.2006 | Luc Binette | L. Binette, S. Haro-Corzo, Y. Krongold, A.C. Andersen | The Nature of the Far-UV Break in the Energy Distribution of Quasars | 5 pages,7 figures, to appear in proceedings of the Huatulco meeting
on AGN, RevMex, eds E. Benitez, I. Cruz-Gonzalez & Y. Krongold | null | null | null | astro-ph | null | A prominent continuum steepening is observed in quasar energy distributions
near 1100A. We review possible interpretations for the physical origin of this
so-called far-UV break.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:29:11 GMT"
}
] | 2007-06-15T00:00:00 | [
[
"Binette",
"L.",
""
],
[
"Haro-Corzo",
"S.",
""
],
[
"Krongold",
"Y.",
""
],
[
"Andersen",
"A. C.",
""
]
] |
0706.2007 | Ilya M. Nemenman | Ilya Nemenman, G. Sean Escola, William S. Hlavacek, Pat J. Unkefer,
Clifford J. Unkefer, Michael E. Wall | Reconstruction of metabolic networks from high-throughput metabolite
profiling data: in silico analysis of red blood cell metabolism | 14 pages, 3 figures. Presented at the DIMACS Workshop on Dialogue on
Reverse Engineering Assessment and Methods (DREAM), Sep 2006 | Ann. N.Y. Acad. Sci. 1115: 102\^a?"115 (2007) | 10.1196/annals.1407.013 | LANL LA-UR-07-3646 | q-bio.MN | null | We investigate the ability of algorithms developed for reverse engineering of
transcriptional regulatory networks to reconstruct metabolic networks from
high-throughput metabolite profiling data. For this, we generate synthetic
metabolic profiles for benchmarking purposes based on a well-established model
for red blood cell metabolism. A variety of data sets is generated, accounting
for different properties of real metabolic networks, such as experimental
noise, metabolite correlations, and temporal dynamics. These data sets are made
available online. We apply ARACNE, a mainstream transcriptional networks
reverse engineering algorithm, to these data sets and observe performance
comparable to that obtained in the transcriptional domain, for which the
algorithm was originally designed.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:41:36 GMT"
}
] | 2007-11-19T00:00:00 | [
[
"Nemenman",
"Ilya",
""
],
[
"Escola",
"G. Sean",
""
],
[
"Hlavacek",
"William S.",
""
],
[
"Unkefer",
"Pat J.",
""
],
[
"Unkefer",
"Clifford J.",
""
],
[
"Wall",
"Michael E.",
""
]
] |
0706.2008 | Alfred de Wijn | A. G. de Wijn, R. J. Rutten, E. M. W. P. Haverkamp, P. S\"utterlin | DOT tomography of the solar atmosphere. IV. Magnetic patches in
internetwork areas | 8 pages, 6 figures | Astron.Astrophys.441:1183-1190,2005 | 10.1051/0004-6361:20053373 | null | astro-ph | null | We use G-band and Ca II H image sequences from the Dutch Open Telescope (DOT)
to study magnetic elements that appear as bright points in internetwork parts
of the quiet solar photosphere and chromosphere. We find that many of these
bright points appear recurrently with varying intensity and horizontal motion
within longer-lived magnetic patches. We develop an algorithm for detection of
the patches and find that all patches identified last much longer than the
granulation. The patches outline cell patterns on mesogranular scales,
indicating that magnetic flux tubes are advected by granular flows to
mesogranular boundaries. Statistical analysis of the emergence and
disappearance of the patches points to an average patch lifetime as long as
530+-50 min (about nine hours), which suggests that the magnetic elements
constituting strong internetwork fields are not generated by a local turbulent
dynamo.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:44:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"de Wijn",
"A. G.",
""
],
[
"Rutten",
"R. J.",
""
],
[
"Haverkamp",
"E. M. W. P.",
""
],
[
"Sütterlin",
"P.",
""
]
] |
0706.2009 | Laura V. Sales | L. V. Sales, J. F. Navarro, D. G. Lambas, S. D. M. White, D. J. Croton | Satellite Galaxies and Fossil Groups in the Millennium Simulation | 18 pages, 14 figures, MNRAS in press. Accepted version with minor
changes. Version with high resolution figures available at:
http://www.astro.uvic.ca/~lsales/SatPapers/SatPapers.html | null | 10.1111/j.1365-2966.2007.12507.x | null | astro-ph | null | We use a semianalytic galaxy catalogue constructed from the Millennium
Simulation to study the satellites of isolated galaxies in the LCDM cosmogony.
This sample (~80,000$ bright primaries, surrounded by ~178,000 satellites)
allows the characterization, with minimal statistical uncertainty, of the
dynamical properties of satellite/primary galaxy systems in a LCDM universe. We
find that, overall, the satellite population traces the dark matter rather
well: its spatial distribution and kinematics may be approximated by an NFW
profile with a mildly anisotropic velocity distribution. Their spatial
distribution is also mildly anisotropic, with a well-defined ``anti-Holmberg''
effect that reflects the misalignment between the major axis and angular
momentum of the host halo. The isolation criteria for our primaries picks not
only galaxies in sparse environments, but also a number of primaries at the
centre of ''fossil'' groups. We find that the abundance and luminosity function
of these unusual systems are in reasonable agreement with the few available
observational constraints. We recover the expected L_{host} \sigma_{sat}^3
relation for LCDM models for truly-isolated primaries. Less strict primary
selection, however, leads to substantial modification of the scaling relation.
Our analysis also highlights a number of difficulties afflicting studies that
rely on blind stacking of satellite systems to constrain the mean halo mass of
the primary galaxies.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 22:50:05 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 14:45:59 GMT"
},
{
"version": "v3",
"created": "Sun, 24 Jun 2007 14:34:41 GMT"
},
{
"version": "v4",
"created": "Thu, 27 Sep 2007 08:31:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sales",
"L. V.",
""
],
[
"Navarro",
"J. F.",
""
],
[
"Lambas",
"D. G.",
""
],
[
"White",
"S. D. M.",
""
],
[
"Croton",
"D. J.",
""
]
] |
0706.2010 | Anne Broadbent | Anne Broadbent and Alain Tapp | Information-theoretic security without an honest majority | 15 pages, to appear in Proceedings of ASIACRYPT 2007 | Proceedings of ASIACRYPT 2007 pp. 410-426 | 10.1007/978-3-540-76900-2_25 | null | cs.CR | null | We present six multiparty protocols with information-theoretic security that
tolerate an arbitrary number of corrupt participants. All protocols assume
pairwise authentic private channels and a broadcast channel (in a single case,
we require a simultaneous broadcast channel). We give protocols for veto, vote,
anonymous bit transmission, collision detection, notification and anonymous
message transmission. Not assuming an honest majority, in most cases, a single
corrupt participant can make the protocol abort. All protocols achieve
functionality never obtained before without the use of either computational
assumptions or of an honest majority.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 23:05:40 GMT"
}
] | 2016-01-06T00:00:00 | [
[
"Broadbent",
"Anne",
""
],
[
"Tapp",
"Alain",
""
]
] |
0706.2011 | Alfred de Wijn | A. G. de Wijn, B. De Pontieu | Dynamic fibrils in H-alpha and C IV | 8 pages, 8 figures | Astron.Astrophys.460:309-316,2006 | 10.1051/0004-6361:20065864 | null | astro-ph | null | Aim: To study the interaction of the solar chromosphere with the transition
region, in particular active-region jets in the transition region and their
relation to chromospheric fibrils. Methods: We carefully align image sequences
taken simultaneously in C IV with the Transition Region and Coronal Explorer
and in H-alpha with the Swedish 1-m Solar Telescope. We examine the temporal
evolution of "dynamic fibrils", i.e., individual short-lived active-region
chromospheric jet-like features in H-alpha. Results: All dynamic fibrils appear
as absorption features in H-alpha that progress from the blue to the red wing
through the line, and often show recurrent behavior. Some of them, but not all,
appear also as bright features in C IV which develop at or just beyond the apex
of the H-alpha darkening. They tend to best resemble the H-alpha fibril at +700
mA half a minute earlier. Conclusions: Dynamic chromospheric fibrils observed
in H-alpha regularly correspond to transition-region jets observed in the
ultraviolet. This correspondence suggests that some plasma associated with
dynamic fibrils is heated to transition-region temperatures.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 23:22:49 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"de Wijn",
"A. G.",
""
],
[
"De Pontieu",
"B.",
""
]
] |
0706.2012 | Masanori Kohno | Masanori Kohno, Oleg A. Starykh, Leon Balents | Spinons and triplons in spatially anisotropic frustrated
antiferromagnets | 16 pages, 6 figures | Nature Physics 3, 790 - 795 (2007) | 10.1038/nphys749 | null | cond-mat.str-el cond-mat.stat-mech | null | The search for elementary excitations with fractional quantum numbers is a
central challenge in modern condensed matter physics. We explore the
possibility in a realistic model for several materials, the spin-1/2 spatially
anisotropic frustrated Heisenberg antiferromagnet in two dimensions. By
restricting the Hilbert space to that expressed by exact eigenstates of the
Heisenberg chain, we derive an effective Schr\"odinger equation valid in the
weak interchain-coupling regime. The dynamical spin correlations from this
approach agree quantitatively with inelastic neutron measurements on the
triangular antiferromagnet Cs_2CuCl_4. The spectral features in such
antiferromagnets can be attributed to two types of excitations: descendents of
one-dimensional spinons of individual chains, and coherently propagating
"triplon" bound states of spinon pairs. We argue that triplons are generic
features of spatially anisotropic frustrated antiferromagnets, and arise
because the bound spinon pair lowers its kinetic energy by propagating between
chains.
| [
{
"version": "v1",
"created": "Thu, 14 Jun 2007 06:13:53 GMT"
}
] | 2009-03-23T00:00:00 | [
[
"Kohno",
"Masanori",
""
],
[
"Starykh",
"Oleg A.",
""
],
[
"Balents",
"Leon",
""
]
] |
0706.2013 | Yuval Peres | Nicholas James, Russell Lyons, Yuval Peres | A transient Markov chain with finitely many cutpoints | Published in at http://dx.doi.org/10.1214/193940307000000365 the IMS
Collections (http://www.imstat.org/publications/imscollections.htm) by the
Institute of Mathematical Statistics (http://www.imstat.org) | IMS Collections 2008, Vol. 2, 24-29 | 10.1214/193940307000000365 | IMS-COLL2-IMSCOLL203 | math.PR | null | We give an example of a transient reversible Markov chain that almost surely
has only a finite number of cutpoints. We explain how this is relevant to a
conjecture of Diaconis and Freedman and a question of Kaimanovich. We also
answer Kaimanovich's question when the Markov chain is a nearest-neighbor
random walk on a tree.
| [
{
"version": "v1",
"created": "Wed, 13 Jun 2007 23:56:54 GMT"
},
{
"version": "v2",
"created": "Mon, 19 May 2008 14:38:26 GMT"
}
] | 2008-05-19T00:00:00 | [
[
"James",
"Nicholas",
""
],
[
"Lyons",
"Russell",
""
],
[
"Peres",
"Yuval",
""
]
] |
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