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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0705.4298 | Gregory Mack | Gregory D. Mack (Ohio State), John F. Beacom (Ohio State), and
Gianfranco Bertone (IAP) | Towards Closing the Window on Strongly Interacting Dark Matter:
Far-Reaching Constraints from Earth's Heat Flow | 12 pages, 2 figures; minor updates to match published version | Phys.Rev.D76:043523,2007 | 10.1103/PhysRevD.76.043523 | null | astro-ph hep-ph nucl-th | null | We point out a new and largely model-independent constraint on the dark
matter scattering cross section with nucleons, applying when this quantity is
larger than for typical weakly interacting dark matter candidates. When the
dark matter capture rate in Earth is efficient, the rate of energy deposition
by dark matter self-annihilation products would grossly exceed the measured
heat flow of Earth. This improves the spin-independent cross section
constraints by many orders of magnitude, and closes the window between
astrophysical constraints (at very large cross sections) and underground
detector constraints (at small cross sections). In the applicable mass range,
from about 1 to about 10^{10} GeV, the scattering cross section of dark matter
with nucleons is then bounded from above by the latter constraints, and hence
must be truly weak, as usually assumed.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 21:22:45 GMT"
},
{
"version": "v2",
"created": "Fri, 12 Oct 2007 18:15:13 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Mack",
"Gregory D.",
"",
"Ohio State"
],
[
"Beacom",
"John F.",
"",
"Ohio State"
],
[
"Bertone",
"Gianfranco",
"",
"IAP"
]
] |
0705.4299 | Angelo B. Mingarelli | Angelo B. Mingarelli | Abstract factorials | 35 pages, preprint. Submitted. This version replaces all previous
versions of the paper "Abstract factorial functions and their applications" | null | null | null | math.NT math.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A commutative semigroup of abstract factorials is defined in the context of
the ring of integers. We study such factorials for their own sake, whether they
are or are not connected to sets of integers. Given a subset X of the positive
integers we construct a "factorial set" with which one may define a multitude
of abstract factorials on X. We study the possible equality of consecutive
factorials, a dichotomy involving the limit superior of the ratios of
consecutive factorials and we provide many examples outlining the applications
of the ensuing theory; examples dealing with prime numbers, Fibonacci numbers,
and highly composite numbers among other sets of integers. One of our results
states that given any abstract factorial the series of reciprocals of its
factorials always converges to an irrational number. Thus, for example, for any
positive integer k the series of the reciprocals of the k-th powers of the
cumulative product of the divisors of the numbers from 1 to n is irrational.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 21:41:13 GMT"
},
{
"version": "v2",
"created": "Sun, 11 Nov 2007 12:13:51 GMT"
},
{
"version": "v3",
"created": "Tue, 10 Jul 2012 10:42:23 GMT"
}
] | 2012-07-11T00:00:00 | [
[
"Mingarelli",
"Angelo B.",
""
]
] |
0705.4300 | Robert Brownlee | R. A. Brownlee | Error estimates for interpolation of rough data using the scattered
shifts of a radial basis function | 12 pages | Numer. Algorithms, 39(1-3):57-68, 2005 | 10.1007/s11075-004-3620-2 | MA-04-15, University of Leicester, UK | math.NA | null | The error between appropriately smooth functions and their radial basis
function interpolants, as the interpolation points fill out a bounded domain in
R^d, is a well studied artifact. In all of these cases, the analysis takes
place in a natural function space dictated by the choice of radial basis
function -- the native space. The native space contains functions possessing a
certain amount of smoothness. This paper establishes error estimates when the
function being interpolated is conspicuously rough.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 16:38:32 GMT"
}
] | 2007-12-02T00:00:00 | [
[
"Brownlee",
"R. A.",
""
]
] |
0705.4301 | Robert Hoy | Robert S. Hoy and Mark O. Robbins | Strain Hardening in Polymer Glasses: Limitations of Network Models | 4 pages, 3 figures | null | 10.1103/PhysRevLett.99.117801 | null | cond-mat.mtrl-sci cond-mat.soft | null | Simulations are used to examine the microscopic origins of strain hardening
in polymer glasses. While traditional entropic network models can be fit to the
total stress, their underlying assumptions are inconsistent with simulation
results. There is a substantial energetic contribution to the stress that rises
rapidly as segments between entanglements are pulled taut. The thermal
component of stress is less sensitive to entanglements, mostly irreversible,
and directly related to the rate of local plastic arrangements. Entangled and
unentangled chains show the same strain hardening when plotted against the
microscopic chain orientation rather than the macroscopic strain.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 22:10:08 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hoy",
"Robert S.",
""
],
[
"Robbins",
"Mark O.",
""
]
] |
0705.4302 | Jens Oehlschl\"agel | Jens Oehlschl\"agel | Truecluster matching | 15 pages, 2 figures. Details the matching needed for "Truecluster:
robust scalable clustering with model selection" but can also be used in
different contexts | null | null | null | cs.AI | null | Cluster matching by permuting cluster labels is important in many clustering
contexts such as cluster validation and cluster ensemble techniques. The
classic approach is to minimize the euclidean distance between two cluster
solutions which induces inappropriate stability in certain settings. Therefore,
we present the truematch algorithm that introduces two improvements best
explained in the crisp case. First, instead of maximizing the trace of the
cluster crosstable, we propose to maximize a chi-square transformation of this
crosstable. Thus, the trace will not be dominated by the cells with the largest
counts but by the cells with the most non-random observations, taking into
account the marginals. Second, we suggest a probabilistic component in order to
break ties and to make the matching algorithm truly random on random data. The
truematch algorithm is designed as a building block of the truecluster
framework and scales in polynomial time. First simulation results confirm that
the truematch algorithm gives more consistent truecluster results for unequal
cluster sizes. Free R software is available.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 21:52:17 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Oehlschlägel",
"Jens",
""
]
] |
0705.4303 | Ahmed Younes Dr. | Ahmed Younes | Database Manipulation on Quantum Computers | null | null | null | null | quant-ph | null | Manipulating a database system on a quantum computer is an essential aim to
benefit from the promising speed-up of quantum computers over classical
computers in areas that take a vast amount of storage and processing time such
as in databases. In this paper, the basic operations for manipulating the data
in a quantum database will be defined, e.g. INSERT, UPDATE, DELETE, SELECT,
backing up and restoring a database file. This gives the ability to perform the
data processing that usually takes a long processing time on a classical
database system, in a simultaneous way on a quantum computer. Defining a
quantum version of more advanced concepts used in database systems, e.g. the
referential integrity and the relational algebra, is a normal extension to this
work
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 22:08:48 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Younes",
"Ahmed",
""
]
] |
0705.4304 | Akram Aldroubi | A. Aldroubi, A. Baskakov, and I. Krishtal | Slanted matrices, Banach frames, and sampling | null | null | null | null | math.FA math.SP | null | In this paper we present a rare combination of abstract results on the
spectral properties of slanted matrices and some of their very specific
applications to frame theory and sampling problems. We show that for a large
class of slanted matrices boundedness below of the corresponding operator in
$\ell^p$ for some $p$ implies boundedness below in $\ell^p$ for all $p$. We use
the established resultto enrich our understanding of Banach frames and obtain
new results for irregular sampling problems. We also present a version of a
non-commutative Wiener's lemma for slanted matrices.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 21:59:21 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Aldroubi",
"A.",
""
],
[
"Baskakov",
"A.",
""
],
[
"Krishtal",
"I.",
""
]
] |
0705.4305 | Paolo Benincasa | Paolo Benincasa, Freddy Cachazo | Consistency Conditions on the S-Matrix of Massless Particles | 30 pages, 2 figures | null | null | null | hep-th | null | We introduce a set of consistency conditions on the S-matrix of theories of
massless particles of arbitrary spin in four-dimensional Minkowski space-time.
We find that in most cases the constraints, derived from the conditions, can
only be satisfied if the S-matrix is trivial. Our conditions apply to theories
where four-particle scattering amplitudes can be obtained from three-particle
ones via a recent technique called BCFW construction. We call theories in this
class constructible. We propose a program for performing a systematic search of
constructible theories that can have non-trivial S-matrices. As illustrations,
we provide simple proofs of already known facts like the impossibility of spin
$s > 2$ non-trivial S-matrices, the impossibility of several spin 2 interacting
particles and the uniqueness of a theory with spin 2 and spin 3/2 particles.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 22:01:28 GMT"
},
{
"version": "v2",
"created": "Thu, 17 Jan 2008 20:40:23 GMT"
}
] | 2008-01-17T00:00:00 | [
[
"Benincasa",
"Paolo",
""
],
[
"Cachazo",
"Freddy",
""
]
] |
0705.4306 | Yitang Zhang | Yitang Zhang | On the Landau-Siegel Zeros Conjecture | about 54 paqes | null | null | null | math.NT | null | We provide a proof of a variant of the Landau-Siegel Zeros conjecture.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 22:03:34 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Zhang",
"Yitang",
""
]
] |
0705.4307 | Jose Wudka | Bohdan Grzadkowski and Jose Wudka | Note on the strong CP problem from a 5-dimensional perspective | 6 pages, no figures | Phys.Rev.D77:096004,2008 | 10.1103/PhysRevD.77.096004 | IFT-07-02; UCRHEP-T434 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider 5 dimensional gauge theories where the 5th direction is
compactified on an interval. The Chern-Simons (CS) terms (favored by naive
dimensional analysis) are discussed. A simple scenario with an extra U(1)_X
gauge field that couples to SU(3)_{color} through a CS term in the bulk is
constructed. The extra component of the Abelian gauge field plays a role of the
axion, which in the standard manner solves the strong CP problem easily
avoiding most of experimental constraints.
This version has an expanded discussion of the phenomenology of the model and
various clarifications in the estimation of the operator coefficients in the
appendix.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 22:07:30 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Apr 2009 23:57:14 GMT"
}
] | 2009-04-21T00:00:00 | [
[
"Grzadkowski",
"Bohdan",
""
],
[
"Wudka",
"Jose",
""
]
] |
0705.4308 | Mark Van Raamsdonk | Hsien-Hang Shieh, Greg van Anders and Mark Van Raamsdonk | Coarse-Graining the Lin-Maldacena Geometries | 29 pages, LaTeX, 3 figures; v2 references added | JHEP 0709:059,2007 | 10.1088/1126-6708/2007/09/059 | null | hep-th | null | The Lin-Maldacena geometries are nonsingular gravity duals to degenerate
vacuum states of a family of field theories with SU(2|4) supersymmetry. In this
note, we show that at large N, where the number of vacuum states is large,
there is a natural `macroscopic' description of typical states, giving rise to
a set of coarse-grained geometries. For a given coarse-grained state, we can
associate an entropy related to the number of underlying microstates. We find a
simple formula for this entropy in terms of the data that specify the geometry.
We see that this entropy function is zero for the original microstate
geometries and maximized for a certain ``typical state'' geometry, which we
argue is the gravity dual to the zero-temperature limit of the thermal state of
the corresponding field theory. Finally, we note that the coarse-grained
geometries are singular if and only if the entropy function is non-zero.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 19:04:33 GMT"
},
{
"version": "v2",
"created": "Sun, 19 Aug 2007 13:53:46 GMT"
}
] | 2009-04-30T00:00:00 | [
[
"Shieh",
"Hsien-Hang",
""
],
[
"van Anders",
"Greg",
""
],
[
"Van Raamsdonk",
"Mark",
""
]
] |
0705.4309 | Akram Aldroubi | E. costa-Reyes, A. Aldroubi, I. Krishtal | On Stability of Sampling-Reconstruction Models | 26 pages | null | null | null | math.GM math.FA | null | A useful sampling-reconstruction model should be stable with respect to
different kind of small perturbations, regardless whether they result from
jitter, measurement errors, or simply from a small change in the model
assumptions. In this paper we prove this result for a large class of sampling
models. We define different classes of perturbations and quantify the
robustness of a model with respect to them. We also use the theory of localized
frames to study the frame algorithm for recovering the original signal from its
samples.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 22:10:20 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"costa-Reyes",
"E.",
""
],
[
"Aldroubi",
"A.",
""
],
[
"Krishtal",
"I.",
""
]
] |
0705.4310 | Susan Cox | Susan Cox, J. Singleton, R.D. McDonald, A. Migliori, P.B. Littlewood | Sliding charge density wave in manganites | 13 pages; 4 figures | null | 10.1038/nmat2071 | null | cond-mat.str-el cond-mat.mtrl-sci | null | The so-called stripe phase of the manganites is an important example of the
complex behaviour of metal oxides, and has long been interpreted as the
localisation of charge at atomic sites. Here, we demonstrate via resistance
measurements on La_{0.50}Ca_{0.50}MnO_3 that this state is in fact a
prototypical charge density wave (CDW) which undergoes collective transport.
Dramatic resistance hysteresis effects and broadband noise properties are
observed, both of which are typical of sliding CDW systems. Moreover, the high
levels of disorder typical of manganites result in behaviour similar to that of
well-known disordered CDW materials. Our discovery that the manganite
superstructure is a CDW shows that unusual transport and structural properties
do not require exotic physics, but can emerge when a well-understood phase (the
CDW) coexists with disorder.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 22:13:50 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 05:02:31 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cox",
"Susan",
""
],
[
"Singleton",
"J.",
""
],
[
"McDonald",
"R. D.",
""
],
[
"Migliori",
"A.",
""
],
[
"Littlewood",
"P. B.",
""
]
] |
0705.4311 | Floyd Stecker | F. W. Stecker, S. D. Hunter and D. A. Kniffen (NASA/GSFC) | The Likely Cause of the EGRET GeV Anomaly and its Implications | 12 pages, 3 figs., Astroparticle Physics, in press | Astropart.Phys.29:25-29,2008 | 10.1016/j.astropartphys.2007.11.002 | null | astro-ph | null | Analysis of data from the EGRET gamma-ray detector on the Compton Gamma Ray
Observatory indicated an anomaly in the form of an excess diffuse galactic flux
at GeV energies over that which was theoretically predicted. Various
explanations for this anomaly have been put forth, including the invocation of
supersymmetric dark matter annihilation. We reexamine these explanations here,
including a new discussion of the possible systematic errors in the sensitivity
determination of the EGRET detector. We conclude that the most likely
explanation of the EGRET ``GeV anomaly'' was an error in the estimation of the
of the EGRET sensitivity at energies above ~1 GeV. We give reasons why such a
situation could have occurred. We find evidence from our new all-sky analysis
which is inconsistent with the assumption that the anomaly can be a signal of
supersymmetric dark matter annihilation. We also reconfirm the original results
of the EGRET team on the extragalactic gamma-ray background spectrum. There are
important implications of our analysis for the upcoming Gamma Ray Large Area
Telescope (GLAST) mission.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 22:35:19 GMT"
},
{
"version": "v2",
"created": "Wed, 6 Jun 2007 19:30:58 GMT"
},
{
"version": "v3",
"created": "Fri, 9 Nov 2007 14:43:23 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Stecker",
"F. W.",
"",
"NASA/GSFC"
],
[
"Hunter",
"S. D.",
"",
"NASA/GSFC"
],
[
"Kniffen",
"D. A.",
"",
"NASA/GSFC"
]
] |
0705.4312 | Marcus Hutter | Alberto Piatti and Marco Zaffalon and Fabio Trojani and Marcus Hutter | Learning about a Categorical Latent Variable under Prior Near-Ignorance | 15 LaTeX pages | Proc. 5th International Symposium on Imprecise Probability:
Theories and Applications (ISIPTA 2007) pages 357-364 | null | IDSIA-05-07 | math.PR math.ST stat.TH | null | It is well known that complete prior ignorance is not compatible with
learning, at least in a coherent theory of (epistemic) uncertainty. What is
less widely known, is that there is a state similar to full ignorance, that
Walley calls near-ignorance, that permits learning to take place. In this paper
we provide new and substantial evidence that also near-ignorance cannot be
really regarded as a way out of the problem of starting statistical inference
in conditions of very weak beliefs. The key to this result is focusing on a
setting characterized by a variable of interest that is latent. We argue that
such a setting is by far the most common case in practice, and we show, for the
case of categorical latent variables (and general manifest variables) that
there is a sufficient condition that, if satisfied, prevents learning to take
place under prior near-ignorance. This condition is shown to be easily
satisfied in the most common statistical problems.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 22:38:10 GMT"
}
] | 2008-06-26T00:00:00 | [
[
"Piatti",
"Alberto",
""
],
[
"Zaffalon",
"Marco",
""
],
[
"Trojani",
"Fabio",
""
],
[
"Hutter",
"Marcus",
""
]
] |
0705.4313 | Michal Mocko | M. Mocko, M. B. Tsang, Z. Y. Sun, N. Aoi, J. Cook, F. Delaunay, M. A.
Famiano, H. Hui, N. Imai, H. Iwasaki, W. G. Lynch, T. Motobayashi, M.
Niikura, T. Onishi, A. M. Rogers, H. Sakurai, A. Stolz, H. Suzuki, E.
Takeshita, S. Takeuchi, and M. S. Wallace | Projectile Fragmentation of $^{86}$Kr at 64 MeV/nucleon | 27 pages, 12 figures, submitted to PRC | Phys.Rev.C76:014609,2007 | 10.1103/PhysRevC.76.014609 | null | nucl-ex | null | We measured fragmentation cross sections produced using the primary beam of
$^{86}$Kr at 64 MeV/nucleon on $^9$Be and $^{181}$Ta targets. The cross
sections were obtained by integrating the momentum distributions of isotopes
with 25<Z<36 measured using the RIPS fragment separator at RIKEN. The
cross-section ratios obtained with the $^{181}$Ta and $^{9}$Be targets depend
on the fragment masses, contrary to the simple geometrical models. We compared
the extracted cross sections to EPAX; an empirical parameterization of
fragmentation cross sections. Predictions from current EPAX parameterization
severely overestimate the production cross sections of very neutron-rich
isotopes. Attempts to obtain another set of EPAX parameters specific to the
reaction studied here, to extrapolate the neutron-rich nuclei more accurately
have not been very successful, suggesting that accurate predictions of
production cross sections of nuclei far from the valley of stability require
information of nuclear properties which are not present in EPAX.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 23:02:44 GMT"
},
{
"version": "v2",
"created": "Wed, 30 May 2007 22:02:19 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Mocko",
"M.",
""
],
[
"Tsang",
"M. B.",
""
],
[
"Sun",
"Z. Y.",
""
],
[
"Aoi",
"N.",
""
],
[
"Cook",
"J.",
""
],
[
"Delaunay",
"F.",
""
],
[
"Famiano",
"M. A.",
""
],
[
"Hui",
"H.",
""
],
[
"Imai",
"N.",
""
],
[
"Iwasaki",
"H.",
""
],
[
"Lynch",
"W. G.",
""
],
[
"Motobayashi",
"T.",
""
],
[
"Niikura",
"M.",
""
],
[
"Onishi",
"T.",
""
],
[
"Rogers",
"A. M.",
""
],
[
"Sakurai",
"H.",
""
],
[
"Stolz",
"A.",
""
],
[
"Suzuki",
"H.",
""
],
[
"Takeshita",
"E.",
""
],
[
"Takeuchi",
"S.",
""
],
[
"Wallace",
"M. S.",
""
]
] |
0705.4314 | Mark Wilde | Mark M. Wilde, Hari Krovi, Todd A. Brun | Entanglement-Assisted Quantum Error Correction with Linear Optics | 8 pages, 1 figure, major expansion of paper with detailed example | Physical Review A 76, 052308 (2007) | 10.1103/PhysRevA.76.052308 | CSI-07-11-02 | quant-ph | null | We construct a theory of continuous-variable entanglement-assisted quantum
error correction. We present an example of a continuous-variable
entanglement-assisted code that corrects for an arbitrary single-mode error. We
also show how to implement encoding circuits using passive optical devices,
homodyne measurements, feedforward classical communication, conditional
displacements, and off-line squeezers.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 23:12:04 GMT"
},
{
"version": "v2",
"created": "Thu, 31 May 2007 17:31:54 GMT"
},
{
"version": "v3",
"created": "Fri, 10 Aug 2007 23:21:07 GMT"
}
] | 2007-11-13T00:00:00 | [
[
"Wilde",
"Mark M.",
""
],
[
"Krovi",
"Hari",
""
],
[
"Brun",
"Todd A.",
""
]
] |
0705.4315 | Claudio Nassif | Claudio Nassif | A fundamental explanation for the tiny value of the cosmological
constant | 32 pages and 7 figures. Submitted for publication | null | null | null | physics.gen-ph | null | We will look for an implementation of new symmetries in the space-time
structure and their cosmological implications. This search will allow us to
find a unified vision for electrodynamics and gravitation. We will attempt to
develop a heuristic model of the electromagnetic nature of the electron, so
that the influence of the gravitational field on the electrodynamics at very
large distances leads to a reformulation of our comprehension of the space-
time structure at quantum level through the elimination of the classical idea
of rest. This will lead us to a modification of the relativistic theory by
introducing the idea about a universal minimum limit of speed in the space-
time. Such a limit, unattainable by the particles, represents a preferred frame
associated with a universal background field (a vacuum energy), enabling a
fundamental understanding of the quantum uncertainties. The structure of
space-time becomes extended due to such a vacuum energy density, which leads to
a negative pressure at the cosmological scales as an anti-gravity, playing the
role of the cosmological constant. The tiny values of the vacuum energy density
and the cosmological constant will be successfully obtained, being in agreement
with current observational results.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 23:14:23 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 13:36:15 GMT"
},
{
"version": "v3",
"created": "Sat, 4 Aug 2007 20:31:32 GMT"
},
{
"version": "v4",
"created": "Fri, 7 Sep 2007 23:17:53 GMT"
},
{
"version": "v5",
"created": "Tue, 18 Sep 2007 17:37:28 GMT"
},
{
"version": "v6",
"created": "Fri, 26 Oct 2007 00:30:19 GMT"
},
{
"version": "v7",
"created": "Fri, 2 Nov 2007 22:44:58 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Nassif",
"Claudio",
""
]
] |
0705.4316 | Sungho Hong | Brian Nils Lundstrom, Sungho Hong, Matthew H. Higgs, and Adrienne L.
Fairhall (U. Washington) | Two computational regimes of a single-compartment neuron separated by a
planar boundary in conductance space | 18 pages, 5 figures, accepted version | null | null | null | q-bio.NC physics.bio-ph | null | Recent in vitro data show that neurons respond to input variance with varying
sensitivities. Here, we demonstrate that Hodgkin-Huxley (HH) neurons can
operate in two computational regimes, one that is more sensitive to input
variance (differentiating) and one that is less sensitive (integrating). A
boundary plane in the 3D conductance space separates these two regimes. For a
reduced HH model, this plane can be derived analytically from the V nullcline,
thus suggesting a means of relating biophysical parameters to neural
computation by analyzing the neuron's dynamical system.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 23:19:18 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Jul 2007 21:09:20 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Lundstrom",
"Brian Nils",
"",
"U. Washington"
],
[
"Hong",
"Sungho",
"",
"U. Washington"
],
[
"Higgs",
"Matthew H.",
"",
"U. Washington"
],
[
"Fairhall",
"Adrienne L.",
"",
"U. Washington"
]
] |
0705.4317 | Yukihiro Mimura | Bhaskar Dutta, Yukihiro Mimura and Dimitri V. Nanopoulos | No-Scale Solution to Little Hierarchy | 15 pages, 2 figures | Phys.Lett.B656:199-206,2007 | 10.1016/j.physletb.2007.09.047 | MIFP-07-15, ACT-03-07 | hep-ph | null | We show that the little hierarchy problem can be solved in the no-scale
supergravity framework. In this model the supersymmetry breaking scale is
generated when the electroweak symmetry breaking condition is satisfied and
therefore, unlike usual supersymmetric models, the correlation between the
electroweak symmetry breaking scale and the average stop mass scale can be
justified. This correlation solves the little hierarchy puzzle. Using minimal
supergravity boundary conditions, we find that the parameter space predicted by
no-scale supergravity is allowed by all possible experimental constraints. The
predicted values of supersymmetric particle masses are low enough to be very
easily accessible at the LHC. This parameter space will also be probed in the
upcoming results from the dark matter direct detection experiments.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 23:20:57 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Dutta",
"Bhaskar",
""
],
[
"Mimura",
"Yukihiro",
""
],
[
"Nanopoulos",
"Dimitri V.",
""
]
] |
0705.4318 | Edward Ackad | Edward Ackad and Marko Horbatsch | Supercritical Dirac resonance parameters from extrapolated analytic
continuation methods | 20 pages, 3 figures, submitted to Physical Review A | null | 10.1103/PhysRevA.76.022503 | null | physics.atom-ph physics.comp-ph | null | The analytic continuation methods of complex scaling (CS), smooth exterior
scaling (SES), and complex absorbing potential (CAP) are investigated for the
supercritical quasimolecular ground state in the U(92+)-Cf(98+) system at an
internuclear separation of R=20 fm. Pade approximants to the complex-energy
trajectories are used to perform an extrapolation of the resonance energies,
which, thus, become independent of the respective stabilization parameter.
Within the monopole approximation to the two-center potential is demonstrated
that the extrapolated results from SES and CAP are consistent to a high degree
of accuracy. Extrapolated CAP calculations are extended to include dipole and
quadrupole terms of the potential for a large range of internuclear separations
R. These terms cause a broadening of the widths at the permille level when the
nuclei are almost in contact, and at the % level for R values where the ground
state enters the negative continuum.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 23:37:02 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jul 2007 00:22:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ackad",
"Edward",
""
],
[
"Horbatsch",
"Marko",
""
]
] |
0705.4319 | Bram Boroson | Bram Boroson, Saeqa Dil Vrtilek, John C. Raymond, and Martin Still | FUSE Observations of a Full Orbit of Hercules X-1: Signatures of Disk,
Star, and Wind | Accepted for publication in The Astrophysical Journal | null | 10.1086/520826 | null | astro-ph | null | We observed an entire 1.7 day orbit of the X-ray binary Hercules X-1 with the
Far Ultraviolet Spectroscopic Explorer (FUSE). Changes in the O VI 1032,1037
line profiles through eclipse ingress and egress indicate a Keplerian accretion
disk spinning prograde with the orbit. These observations may show the first
double-peaked accretion disk line profile to be seen in the Hercules X-1
system. Doppler tomograms of the emission lines show a bright spot offset from
the Roche lobe of the companion star HZ Her, but no obvious signs of the
accretion disk. Simulations show that the bright spot is too far offset from
the Roche lobe to result from uneven X-ray heating of its surface. The absence
of disk signatures in the tomogram can be reproduced in simulations which
include absorption from a stellar wind. We attempt to diagnose the state of the
emitting gas from the C III 977, C III 1175, and N III 991 emission lines. The
latter may be enhanced through Bowen fluorescence.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 01:19:13 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 22:33:28 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Boroson",
"Bram",
""
],
[
"Vrtilek",
"Saeqa Dil",
""
],
[
"Raymond",
"John C.",
""
],
[
"Still",
"Martin",
""
]
] |
0705.4320 | William Hung | William N. N. Hung, Changjian Gao, Xiaoyu Song, Dan Hammerstrom | Defect-Tolerant CMOL Cell Assignment via Satisfiability | To appear in Nanoelectronic Devices for Defense and Security
(NANO-DDS), Crystal City, Virginia, June 2007 | null | null | null | cs.DM cs.DS | null | We present a CAD framework for CMOL, a hybrid CMOS/ molecular circuit
architecture. Our framework first transforms any logically synthesized circuit
based on AND/OR/NOT gates to a NOR gate circuit, and then maps the NOR gates to
CMOL. We encode the CMOL cell assignment problem as boolean conditions. The
boolean constraint is satisfiable if and only if there is a way to map all the
NOR gates to the CMOL cells. We further investigate various types of static
defects for the CMOL architecture, and propose a reconfiguration technique that
can deal with these defects through our CAD framework. This is the first
automated framework for CMOL cell assignment, and the first to model several
different CMOL static defects. Empirical results show that our approach is
efficient and scalable.
| [
{
"version": "v1",
"created": "Tue, 29 May 2007 23:46:38 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Hung",
"William N. N.",
""
],
[
"Gao",
"Changjian",
""
],
[
"Song",
"Xiaoyu",
""
],
[
"Hammerstrom",
"Dan",
""
]
] |
0705.4321 | Manfred Bucher | Manfred Bucher | Coulomb oscillations as a remedy for the helium atom | 19 pages including 1 table, 6 figures | null | null | null | physics.hist-ph physics.atom-ph | null | The largest failure of the old, Bohr-Sommerfeld quantum theory was with the
helium atom. It brought about the theory's demise. I show that this failure
does not originate, as commonly believed, with the orbit concept per se.
Instead, it was caused by the wrong choice of orbits, compounded by ignorance
of the exclusion principle. Choosing semiclassical electron oscillations
through the He nucleus, I calculate a singlet ground-state energy that rivals
in accuracy with quantum-mechanical results. The same method reveals Bohr's
historic energy value as the forbidden triplet ground state--a result beyond
the reach of quantum mechanics. At the qualitative level, the concept of
Coulomb oscillations visually explains the major features in the He double
spectrum in terms of crossed or parallel orbit orientation.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 00:57:30 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Dec 2007 22:47:43 GMT"
}
] | 2007-12-13T00:00:00 | [
[
"Bucher",
"Manfred",
""
]
] |
0705.4322 | Biao Wu | Z. X. Liang, Xi Dong, Z. D. Zhang, and Biao Wu | Sound speed of a Bose-Einstein condensate in an optical lattice | 15pages 6 figures | Phys.Rev.A78:023622,2008 | 10.1103/PhysRevA.78.023622 | null | cond-mat.other | null | The speed of sound of a Bose-Einstein condensate in an optical lattice is
studied both analytically and numerically in all three dimensions. Our
investigation shows that the sound speed depends strongly on the strength of
the lattice. In the one-dimensional case, the speed of sound falls
monotonically with increasing lattice strength. The dependence on lattice
strength becomes much richer in two and three dimensions. In the
two-dimensional case, when the interaction is weak, the sound speed first
increases then decreases as the lattice strength increases. For the three
dimensional lattice, the sound speed can even oscillate with the lattice
strength. These rich behaviors can be understood in terms of compressibility
and effective mass. Our analytical results at the limit of weak lattices also
offer an interesting perspective to the understanding: they show the lattice
component perpendicular to the sound propagation increases the sound speed
while the lattice components parallel to the propagation decreases the sound
speed. The various dependence of the sound speed on the lattice strength is the
result of this competition.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 01:00:01 GMT"
}
] | 2011-09-13T00:00:00 | [
[
"Liang",
"Z. X.",
""
],
[
"Dong",
"Xi",
""
],
[
"Zhang",
"Z. D.",
""
],
[
"Wu",
"Biao",
""
]
] |
0705.4323 | Takayuki Goto | M. Urano, J. Tonishi, H. Inoue, T. Saito, T. Fujiwara, H. Chiku, A.
Oosawa, T. Goto, T. Suzuki, T. Sasaki, N. Kobayashi, S. Awaji, K. Watanabe | NMR Study on the Vortex Slush Phase in Organic Superconductor
\kappa-(BEDT-TTF)2Cu(NCS)2 | 5 pages, 4 figures | null | 10.1103/PhysRevB.76.024505 | null | cond-mat.str-el cond-mat.supr-con | null | The vortex state in a single crystal of the layered organic superconductor
\kappa-(BEDT-TTF2Cu(NCS)2, where BEDT-TTF (or ET) is
bis(ethylenedithio)tetrathiafulvalene, was studied by 1H-NMR. Under a low field
region around 0.75 T, the vortex glass-liquid transition was demonstrated by a
diverging of the longitudinal nuclear spin relaxation rate and peak-broadening
in spectra. Under a high field region near the upper critical field Hc2(0)~7 T,
the curvature of nuclear spin relaxation curves showed a drastic change at the
temperature where the emergence of the quantum vortex slush state was reported.
The mechanism in this curvature change was discussed in terms of the
fluctuating field produced by fragments of vortex glass.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 01:00:48 GMT"
},
{
"version": "v2",
"created": "Thu, 7 Jun 2007 08:19:38 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Urano",
"M.",
""
],
[
"Tonishi",
"J.",
""
],
[
"Inoue",
"H.",
""
],
[
"Saito",
"T.",
""
],
[
"Fujiwara",
"T.",
""
],
[
"Chiku",
"H.",
""
],
[
"Oosawa",
"A.",
""
],
[
"Goto",
"T.",
""
],
[
"Suzuki",
"T.",
""
],
[
"Sasaki",
"T.",
""
],
[
"Kobayashi",
"N.",
""
],
[
"Awaji",
"S.",
""
],
[
"Watanabe",
"K.",
""
]
] |
0705.4324 | Alexandra Shlapentokh | Alexandra Shlapentokh | Rings of Algebraic Numbers in Infinite Extensions of $\Q$ and Elliptic
Curves Retaining Their Rank | null | null | null | null | math.NT math.LO | null | We show that elliptic curves whose Mordell-Weil groups are finitely generated
over some infinite extensions of $\Q$, can be used to show the Diophantine
undecidability of the rings of integers and bigger rings contained in some
infinite extensions of rational numbers.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 01:10:34 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Shlapentokh",
"Alexandra",
""
]
] |
0705.4325 | Peter Milley | David Gabai (Princeton University), Robert Meyerhoff (Boston College),
Peter Milley (University of Melbourne) | Minimum volume cusped hyperbolic three-manifolds | 57 pages, 14 figures | null | null | null | math.GT | null | This paper is the second in a series whose goal is to understand the
structure of low-volume complete orientable hyperbolic 3-manifolds. Using Mom
technology, we prove that any one-cusped hyperbolic 3-manifold with volume <=
2.848 can be obtained by a Dehn filling on one of 21 cusped hyperbolic
3-manifolds. We also show how this result can be used to construct a complete
list of all one-cusped hyperbolic three-manifolds with volume <= 2.848 and all
closed hyperbolic three-manifolds with volume <= 0.943. In particular, the
Weeks manifold is the unique smallest volume closed orientable hyperbolic
3-manifold.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 03:14:09 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Gabai",
"David",
"",
"Princeton University"
],
[
"Meyerhoff",
"Robert",
"",
"Boston College"
],
[
"Milley",
"Peter",
"",
"University of Melbourne"
]
] |
0705.4326 | Huagui Duan | Huagui Duan, Yiming Long | Multiplicity and stability of closed geodesics on bumpy Finsler
3-spheres | 17 pages. Some modifications have been made. accepted by Calc. Var. &
PDEs | null | null | null | math.DG | null | We prove that for every $\Q$-homological Finsler 3-sphere $(M,F)$ with a
bumpy and irreversible metric $F$, either there exist two non-hyperbolic prime
closed geodesics, or there exist at least three prime closed geodesics.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 01:54:58 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 02:25:12 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Duan",
"Huagui",
""
],
[
"Long",
"Yiming",
""
]
] |
0705.4327 | Huagui Duan | Huagui Duan, Yiming Long | Multiple closed geodesics on bumpy Finsler $n$-spheres | 22 pages | J. Differential Equations 233 (2007) 221-240 | 10.1016/j.jde.2006.10.002 | null | math.DG | null | In this paper we prove that for every bumpy Finsler metric $F$ on every
rationally homological $n$-dimensional sphere $S^n$ with $n\ge 2$, there exist
always at least two distinct prime closed geodesics.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 02:16:49 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Duan",
"Huagui",
""
],
[
"Long",
"Yiming",
""
]
] |
0705.4328 | Frederick Matsen IV | Frederick A. Matsen, Elchanan Mossel and Mike Steel | Mixed-up trees: the structure of phylogenetic mixtures | null | null | null | null | q-bio.PE | null | In this paper we apply new geometric and combinatorial methods to the study
of phylogenetic mixtures. The focus of the geometric approach is to describe
the geometry of phylogenetic mixture distributions for the two state random
cluster model, which is a generalization of the two state symmetric (CFN)
model. In particular, we show that the set of mixture distributions forms a
convex polytope and we calculate its dimension; corollaries include a simple
criterion for when a mixture of branch lengths on the star tree can mimic the
site pattern frequency vector of a resolved quartet tree. Furthermore, by
computing volumes of polytopes we can clarify how ``common'' non-identifiable
mixtures are under the CFN model. We also present a new combinatorial result
which extends any identifiability result for a specific pair of trees of size
six to arbitrary pairs of trees. Next we present a positive result showing
identifiability of rates-across-sites models. Finally, we answer a question
raised in a previous paper concerning ``mixed branch repulsion'' on trees
larger than quartet trees under the CFN model.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 02:43:12 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Sep 2007 11:27:28 GMT"
},
{
"version": "v3",
"created": "Thu, 8 Nov 2007 18:40:45 GMT"
}
] | 2007-11-08T00:00:00 | [
[
"Matsen",
"Frederick A.",
""
],
[
"Mossel",
"Elchanan",
""
],
[
"Steel",
"Mike",
""
]
] |
0705.4329 | Marco Bartolozzi Dr | M. Bartolozzi | Scale-free avalanches in the multifractal random walk | 9 pages, 13 figures. In press: European Physical Journal B | null | 10.1140/epjb/e2007-00178-3 | null | physics.data-an physics.soc-ph q-fin.ST | null | Avalanches, or Avalanche-like, events are often observed in the dynamical
behaviour of many complex systems which span from solar flaring to the Earth's
crust dynamics and from traffic flows to financial markets. Self-organized
criticality (SOC) is one of the most popular theories able to explain this
intermittent charge/discharge behaviour. Despite a large amount of theoretical
work, empirical tests for SOC are still in their infancy. In the present paper
we address the common problem of revealing SOC from a simple time series
without having much information about the underlying system. As a working
example we use a modified version of the multifractal random walk originally
proposed as a model for the stock market dynamics. The study reveals, despite
the lack of the typical ingredients of SOC, an avalanche-like dynamics similar
to that of many physical systems. While, on one hand, the results confirm the
relevance of cascade models in representing turbulent-like phenomena, on the
other, they also raise the question about the current state of reliability of
SOC inference from time series analysis.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 02:46:26 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bartolozzi",
"M.",
""
]
] |
0705.4330 | Dave Witte Morris | Vladimir Chernousov, Lucy Lifschitz and Dave Witte Morris | Almost-minimal nonuniform lattices of higher rank | 23 pages. Minor corrections, and added remarks about which of the
subgroups we construct are simply connected | null | null | null | math.GR math.DG math.RT | null | If Gamma is a nonuniform, irreducible lattice in a semisimple Lie group whose
real rank is greater than 1, we show Gamma contains a subgroup that is
isomorphic to a nonuniform, irreducible lattice in either SL(3,R), SL(3,C), or
a direct product SL(2,R)^m x SL(2,C)^n$, with m + n > 1. (In geometric terms,
this can be interpreted as a statement about the existence of totally geodesic
subspaces of finite-volume, noncompact, locally symmetric spaces of higher
rank.) Another formulation of the result states that if G is any isotropic,
almost simple algebraic group over Q (the rational numbers), such that the real
rank of G is greater than 1, then G contains an isotropic, almost simple
Q-subgroup H, such that H is quasisplit, and the real rank of H is greater than
1.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 03:03:30 GMT"
},
{
"version": "v2",
"created": "Fri, 7 Sep 2007 03:48:26 GMT"
},
{
"version": "v3",
"created": "Tue, 13 Nov 2007 20:53:39 GMT"
}
] | 2007-11-13T00:00:00 | [
[
"Chernousov",
"Vladimir",
""
],
[
"Lifschitz",
"Lucy",
""
],
[
"Morris",
"Dave Witte",
""
]
] |
0705.4331 | Kunming Xu | Kunming Xu | A novel spacetime concept for describing electronic motion within a
helium atom | 16 pages 4 figures | Xu, K. A novel spacetime concept for describing electronic motion
within a helium atom, Scientific Research Monthly, 2006 (2), pp.1-7 | null | null | physics.gen-ph | null | Euclidean space and linear algebra do not characterize dynamic electronic
orbitals satisfactorily for even the motion of both electrons in an inert
helium atom cannot be defined in reasonable details. Here the author puts
forward a novel two-dimensional spacetime model from scratch in the context of
defining both electrons in a helium atom. Space and time are treated as two
orthogonal, symmetric and complementary quantities under the atomic spacetime.
Electronic motion observed the rule of differential and integral operations
that were implemented by dynamic trigonometric functions. It is demonstrated
that the atomic spacetime is not a linear vector space with Newtonian time, and
within which calculus has non-classical definition, and complex wave functions
have fresh physical significances. This alternative approach is original,
informative and refreshing but still compatible with quantum mechanics in the
formulation. The description of electronic resonance in helium is also
comparable with classical mechanics such as an oscillating pendulum and with
classical electromagnetism such as an LC oscillator. The study has effectively
unified complex function, calculus, and trigonometry in mathematics, and
provided a prospect for unifying particle physics with classical physics on the
novel spacetime platform.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 03:40:00 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Xu",
"Kunming",
""
]
] |
0705.4332 | Varlen Grabski | V Grabski, A Morales, R Reche, O Orozco | Feasibility for p+/p- flow-ratio evaluation in the 0.5 - 1.5 TeV primary
energy range, based on Moon-shadow muon measurements, to be carried out in
the Pyramid of the Sun, Teotihuacan, Experiment | 4 pages, 6 figures, submitted to ICRC 2007 | Proceedings of the 30th International Cosmic Ray Conference Vol. 5
(HE part 2), pages 1543-1546 | null | null | physics.ins-det | null | Calculations are presented to demonstrate the feasibility of Moon shadow
observations for mean primary energies in the region 0.5-1.5 TeV using a muon
detector operating under the Pyramid of the Sun at Teotihuacan, Mexico. Due to
the small height of that monument (65 m), the experiment is capable of
providing considerably high statistics, although with reduced angular accuracy
for primary particle direction reconstruction. Our estimates are based on
simulations of muon production and transport in the atmosphere by CORSIKA and
along the body of the pyramid by GEANT4. The deflection of primaries in the
earth magnetic field is calculated using the IGRF model. The statistics for the
Moon shadow observations, which depends on different factors affecting the
accuracy of the primary particle direction reconstruction, are analyzed in
detail.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 03:55:19 GMT"
}
] | 2009-01-12T00:00:00 | [
[
"Grabski",
"V",
""
],
[
"Morales",
"A",
""
],
[
"Reche",
"R",
""
],
[
"Orozco",
"O",
""
]
] |
0705.4333 | Ebrahim Samei | Ebrahim Samei | On local properties of Hochschild cohomology of a C$^*$- algebra | 13 pages | null | 10.1017/S1446788708000049 | null | math.OA | null | Let $A$ be a C$^*$-algebra, and let $X$ be a Banach $A$-bimodule. B. E.
Johnson showed that local derivations from $A$ into $X$ are derivations. We
extend this concept of locality to the higher cohomology of a $C^*$-algebra
%for $n$-cocycles from $A^{(n)}$ into $X$ and show that, for every $n\in \N$,
bounded local $n$-cocycles from $A^{(n)}$ into $X$ are $n$-cocycles.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 04:05:20 GMT"
}
] | 2017-11-21T00:00:00 | [
[
"Samei",
"Ebrahim",
""
]
] |
0705.4334 | Jonathan Cohen | Jonathan A. Cohen | Coherence without unique normal forms | 23 pages | null | null | null | math.CT | null | Coherence theorems for covariant structures carried by a category have
traditionally relied on the underlying term rewriting system of the structure
being terminating and confluent. While this holds in a variety of cases, it is
not a feature that is inherent to the coherence problem itself. This is
demonstrated by the theory of iterated monoidal categories, which model
iterated loop spaces and have a coherence theorem but fail to be confluent. We
develop a framework for expressing coherence problems in terms of term
rewriting systems equipped with a two dimensional congruence. Within this
framework we provide general solutions to two related coherence theorems:
Determining whether there is a decision procedure for the commutativity of
diagrams in the resulting structure and determining sufficient conditions
ensuring that ``all diagrams commute''. The resulting coherence theorems rely
on neither the termination nor the confluence of the underlying rewriting
system. We apply the theory to iterated monoidal categories and obtain a new,
conceptual proof of their coherence theorem.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 04:12:23 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Cohen",
"Jonathan A.",
""
]
] |
0705.4335 | Ionel Stetcu | I. Stetcu, B. R. Barrett, U. van Kolck, and J. P. Vary | Effective Theory for Trapped Few-Fermion Systems | 8 pages, 5 figures | Phys.Rev.A76:063613,2007 | 10.1103/PhysRevA.76.063613 | LA-UR-07-3398 | cond-mat.other nucl-th physics.atom-ph | null | We apply the general principles of effective field theories to the
construction of effective interactions suitable for few- and many-body
calculations in a no-core shell model framework. We calculate the spectrum of
systems with three and four two-component fermions in a harmonic trap. In the
unitary limit, we find that three-particle results are within 10% of known
semi-analytical values even in small model spaces. The method is very general,
and can be readily extended to other regimes, more particles, different species
(e.g., protons and neutrons in nuclear physics), or more-component fermions (as
well as bosons). As an illustration, we present calculations of the
lowest-energy three-fermion states away from the unitary limit and find a
possible inversion of parity in the ground state in the limit of trap size
large compared to the scattering length. Furthermore, we investigate the lowest
positive-parity states for four fermions, although we are limited by the
dimensions we can currently handle in this case.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 04:22:02 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Stetcu",
"I.",
""
],
[
"Barrett",
"B. R.",
""
],
[
"van Kolck",
"U.",
""
],
[
"Vary",
"J. P.",
""
]
] |
0705.4336 | Ran Li | Ji-Rong Ren, Ran Li, Fei-Hu Liu | Hawking Temperature of Dilaton Black Holes from Tunneling | 13pages, no figure, references added, Accepted by MPLA | Mod.Phys.Lett.A23:3419-3429,2009 | 10.1142/S0217732308028843 | null | gr-qc | null | Recently, it has been suggested that Hawking radiation can be derived from
quantum tunnelling methods. In this letter, we calculated Hawking temperature
of dilatonic black holes from tunnelling formalism. The two semi-classical
methods adopted here are: the null-geodesic method proposed by Parikh and
Wilczek and the Hamilton-Jacobi method propsed by Angheben et al. We apply the
two methods to anylysis the Hawking temperature of the static spherical
symmetric dilatonic black hole, the rotating Kaluza-Klein black hole, and the
rotating Kerr-Sen black hole.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 04:42:26 GMT"
},
{
"version": "v2",
"created": "Mon, 11 Jun 2007 13:34:08 GMT"
},
{
"version": "v3",
"created": "Fri, 19 Oct 2007 07:41:28 GMT"
}
] | 2009-02-12T00:00:00 | [
[
"Ren",
"Ji-Rong",
""
],
[
"Li",
"Ran",
""
],
[
"Liu",
"Fei-Hu",
""
]
] |
0705.4337 | Ran Li | Ji-Rong Ren, Ran Li, Yi-Shi Duan | Inner topological structure of Hopf invariant | 13pages, no figure. Accepted by J.Math.Phys | J.Math.Phys.48:073502,2007 | 10.1063/1.2747614 | null | math-ph math.MP | null | In light of $\phi$-mapping topological current theory, the inner topological
structure of Hopf invariant is investigated. It is revealed that Hopf invariant
is just the winding number of Gauss mapping. According to the inner structure
of topological current, a precise expression for Hopf invariant is also
presented. It is the total sum of all the self-linking and all the linking
numbers of the knot family.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 04:52:59 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ren",
"Ji-Rong",
""
],
[
"Li",
"Ran",
""
],
[
"Duan",
"Yi-Shi",
""
]
] |
0705.4338 | Ran Li | Yi-Shi Duan, Ji-Rong Ren, Ran Li | Vector and Spinor Decomposition of SU(2) Gauge Potential, their
quivalence and Knot Structure in SU(2) Chern-Simons Theory | 10 pages, ni figure | Commun.Theor.Phys.47:875,2007 | 10.1088/0253-6102/47/5/021 | null | hep-th | null | In this paper, spinor and vector decomposition of SU(2) gauge potential are
presented and their equivalence is constructed using a simply proposal. We also
obtain the action of Faddeev nonlinear O(3) sigma model from the SU(2) massive
gauge field theory which is proposed according to the gauge invariant
principle. At last, the knot structure in SU(2) Chern-Simons filed theory is
discussed in terms of the $\phi$--mapping topological current theory. The
topological charge of the knot is characterized by the Hopf indices and the
Brouwer degrees of $\phi$-mapping.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 05:04:52 GMT"
}
] | 2009-03-19T00:00:00 | [
[
"Duan",
"Yi-Shi",
""
],
[
"Ren",
"Ji-Rong",
""
],
[
"Li",
"Ran",
""
]
] |
0705.4339 | Ran Li | Ji-Rong Ren, Ran Li | Unified First Law and Thermodynamics of Dynamical Black Hole in
n-dimensional Vaidya Spacetime | 3 pages, no figure | Mod.Phys.Lett.A23:3265-3270,2008 | 10.1142/S0217732308028831 | null | gr-qc | null | As a simple but important example of dynamical black hole, we analysis the
dynamical black hole in $n$-dimensional Vaidya spacetime in detail. We
investigated the thermodynamics of field equation in $n$-dimensional Vaidya
spacetime. The unified first law was derived in terms of the methods proposed
by Sean A Hayward. The first law of dynamical black hole was obtained by
projecting the unified first law along the trapping horizon. At last, the
second law of dynamical black hole is also discussed.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 05:12:17 GMT"
},
{
"version": "v2",
"created": "Thu, 31 May 2007 13:39:49 GMT"
}
] | 2010-05-12T00:00:00 | [
[
"Ren",
"Ji-Rong",
""
],
[
"Li",
"Ran",
""
]
] |
0705.4340 | Teruya Yamanishi | T. Yamanishi | F and D Values with Explicit Flavor Symmetry Breaking and \Delta s
Contents of Nucleons | 15 pages, 1 figure, final version to appear in PRD | Phys.Rev.D76:014006,2007 | 10.1103/PhysRevD.76.014006 | FUT-07-01 | hep-ph | null | We propose a new model for describing baryon semi-leptonic decays for
estimating $F$ and $D$ values with explicit breaking effects of both SU(3) and
SU(2) flavor symmetry, where all possible SU(3) and SU(2) breaking effects are
induced from an effective interaction. An overall fit including the weak
magnetism form factor yields $F=0.477\pm 0.001$ and $D=0.835\pm 0.001$ with
$\chi^2=4.43/5$ d.o.f. with $V_{ud}=0.975\pm 0.002$ and $V_{us}=0.221\pm
0.002$. The spin content of strange quarks $\Delta s$ is estimated from the
obtained values $F$ and $D$, and the nucleon spin problem is re-examined.
Furthermore, the unmeasured values of $(g_1/f_1)$ and $(g_1)$ for other hyperon
semi-leptonic decays are predicted from this new formula.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 05:30:24 GMT"
},
{
"version": "v2",
"created": "Sat, 6 Oct 2007 07:56:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Yamanishi",
"T.",
""
]
] |
0705.4341 | Terry Loring A | Terry A. Loring | A Projective C*-Algebra Related to K-Theory | 11 pages. Added a result about the boundary map in K-theory | Journal of Functional Analysis, Volume 254, Issue 12, 15 June
2008, Pages 3079-3092 | 10.1016/j.jfa.2008.03.004 | null | math.OA math.KT | null | The C*-algebra qC is the smallest of the C*-algebras qA introduced by Cuntz
in the context of KK-theory. An important property of qC is the natural
isomorphism of K0 of D with classes of homomorphism from qC to matrix algebras
over D. Our main result concerns the exponential (boundary) map from K0 of a
quotient B to K1 of an ideal I. We show if a K0 element is realized as a
homomorphism from qC to B then its boundary is realized as a unitary in the
unitization of I. The picture we obtain of the exponential map is based on a
projective C*-algebra P that is universal for a set of relations slightly
weaker than the relations that define qC. A new, shorter proof of the
semiprojectivity of qC is described. Smoothing questions related the relations
for qC are addressed.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 05:38:01 GMT"
},
{
"version": "v2",
"created": "Sun, 21 Oct 2007 17:38:13 GMT"
},
{
"version": "v3",
"created": "Mon, 12 Nov 2007 07:02:52 GMT"
},
{
"version": "v4",
"created": "Wed, 5 Mar 2008 01:48:34 GMT"
}
] | 2008-05-28T00:00:00 | [
[
"Loring",
"Terry A.",
""
]
] |
0705.4342 | Norihito Toyota | Norihito Toyota | Network Growth via Preferential Attachment based on Prisoner's Dilemma
Game | 9 pages, 10 figures | null | null | null | physics.soc-ph | null | In this article we discuss network growth based on Prisoner's Dilemma(PD)
where palyers on nodes in a network palay with its linked players. The players
estimate total profits in the PD. When a new node is attached, the node make
linkes to nodes in the network with the probabilities in proportion to the
profits made by the game. Iterating this process, a network grows. We
investigate properties of this type of growing networks, especially the degree
distribution and time-depending strategy distribution by running computer
simulation. We also find a sort of phase transition in the strategy
distributions. For these phenomena given by computer simulation, theoretical
studies are also carried out.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 05:46:08 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Sep 2007 06:12:05 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Toyota",
"Norihito",
""
]
] |
0705.4343 | Takayuki Tanigawa | T. Tanigawa, and M. Ikoma | A Systematic Study of the Final Masses of Gas Giant Planets | Accepted to ApJ, 33 pages, 9 figures | Astrophys.J.667:557-570,2007 | 10.1086/520499 | null | astro-ph | null | We construct an analytic model for the rate of gas accretion onto a planet
embedded in a protoplanetary disk as a function of planetary mass, disk
viscosity, disk scale height, and unperturbed surface density in order to study
the long-term accretion and final masses of gas giant planets. We first derive
an analytical formula for surface density profile near the planetary orbit from
considerations of the balance of force and the dynamical stability. Using it in
the empirical formula linking surface density with gas accretion rate that is
derived based on hydrodynamic simulations of Tanigawa and Watanabe (2002, ApJ
586, 506), we then simulate the mass evolution of gas giant planets in
viscously-evolving disks. We finally determine the final mass as a function of
semi-major axis of the planet. We find that the disk can be divided into three
regions characterized by different processes by which the final mass is
determined. In the inner region, the planet grows quickly and forms a deep gap
to suppress the growth by itself before disk dissipation. The final mass of the
planet in this region is found to increase with the semi-major axis in a
similar way to the mass given by the viscous condition for gap opening, but the
former is larger by a factor of approximately 10 than the latter. In the
intermediate region, viscous diffusion of the disk gas limits the gas accretion
before the planet form a deep gap. The final mass can be up to the disk mass,
when disk viscous evolution occurs faster than disk evaporation. In the outer
region, planets capture only tiny amounts of gas within the lifetime of the
disk to form Neptune-like planets. We derive analytic formulae for the final
masses in the different regions and the locations of the boundaries, which are
helpful to gain a systematic understanding of the masses of gas giant planets.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 07:11:29 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Tanigawa",
"T.",
""
],
[
"Ikoma",
"M.",
""
]
] |
0705.4344 | Chinping Chen | Lin He, Chinping Chen, Ning Wang, Wei Zhou, and Lin Guo | Finite size effect on Neel temperature with Co3O4 nanoparticles | 12 pages, 6 figures, J Appl. Phys. In Press | null | 10.1063/1.2817481 | null | cond-mat.mtrl-sci | null | Finite size effect on the antiferromagnetic transition temperature, TN, of
Co3O4 nanoparticles of 75, 35, and 16 nm in diameter, has been investigated.
The AFM transition point, TN, reduces with the decreasing diameter, d. Along
with the results from the previous experiments on the Co3O4 nanoparticles of 8
and 4.3 nm, the variation of TN with d appears to follow the finite size
relation. According to the scaling behavior, the shift exponent is determined
as \lambda = 1.4 \pm 0.4, the correlation length, \ksi_0 = 3.0 \pm 0.3 nm, and
the bulk Neel temperature, TN(\infint) = 38.6 \pm 0.7 K.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 07:51:55 GMT"
},
{
"version": "v2",
"created": "Tue, 16 Oct 2007 05:00:59 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"He",
"Lin",
""
],
[
"Chen",
"Chinping",
""
],
[
"Wang",
"Ning",
""
],
[
"Zhou",
"Wei",
""
],
[
"Guo",
"Lin",
""
]
] |
0705.4345 | Pasquini Barbara | B. Pasquini and S. Boffi (Pavia U. and INFN, Pavia) | Nucleon spin densities in a light-front constituent quark model | one reference added; to be published in Phys. Lett. B | Phys.Lett.B653:23-28,2007 | 10.1016/j.physletb.2007.07.037 | null | hep-ph | null | The first moment of longitudinal and transverse spin densities of quarks in
the nucleon are calculated in a light-front constituent quark model for the
different cases of quark and nucleon polarization. Significant distortions are
found for the transverse spin densities. In particular the Sivers function is
predicted with opposite sign for up and down quarks and the Boer-Mulders
function is predicted large and negative for both up and down quarks, in
agreement with lattice calculations. Quite a different spin distribution is
obtained for up and down quarks in the cases of quarks and proton transversely
or longitudinally polarized in the same direction.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 07:55:56 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Jul 2007 06:39:28 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Pasquini",
"B.",
"",
"Pavia U. and INFN, Pavia"
],
[
"Boffi",
"S.",
"",
"Pavia U. and INFN, Pavia"
]
] |
0705.4346 | Sergey Cherkas L | V.G. Baryshevsky and S.L. Cherkas | Sensitivity of the neutron crystal diffraction experiment to the neutron
EDM and to the nuclear P-,T-violating forces | The work is supported by the Belarus fund for fundamental research,
grant $Phi$06P-074 | null | null | null | hep-ph | null | We establish a link between an angle of the neutron polarization rotation in
a crystal diffraction experiment and constants of the P-,T- violating
interactions. The consideration applies to the energy range of thermal and
resonance neutrons.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 07:57:02 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Baryshevsky",
"V. G.",
""
],
[
"Cherkas",
"S. L.",
""
]
] |
0705.4347 | Pedro Gonzalez-Diaz | Pedro F. Gonzalez-Diaz, Prado Martin-Moruno and Artyom V. Yurov | A graceful multiversal link of particle physics to cosmology | 10 pages, LaTex | Grav.Cosmol.16:205-215,2010 | 10.1134/S0202289310030035 | IMAFF-RCA-07-08 | astro-ph | null | In this paper we work out a multiverse scenario whose physical
characteristics enable us to advance the following the conjecture that whereas
the physics of particles and fields is confined to live in the realm of the
whole multiverse formed by finite-time single universes, that for our
observable universe must be confined just in one of the infinite number of
universes of the multiverse when such a universe is consistently referred to an
infinite cosmic time. If this conjecture is adopted then some current
fundamental problems that appear when one tries to make compatible particle
physics and cosmology- such as that for the cosmological constant, the arrow of
time and the existence of a finite proper size of the event horizon- can be
solved.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 08:13:04 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Gonzalez-Diaz",
"Pedro F.",
""
],
[
"Martin-Moruno",
"Prado",
""
],
[
"Yurov",
"Artyom V.",
""
]
] |
0705.4348 | Makoto Ozawa | Makoto Ozawa | Edge number of knots and links | 7 pages, 6 figures | null | null | null | math.GT | null | We introduce a new numerical invariant of knots and links made from the
partitioned diagrams. It measures the complexity of knots and links.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 08:16:51 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Ozawa",
"Makoto",
""
]
] |
0705.4349 | Masakazu Kobayashi | Masakazu A. R. Kobayashi (Kyoto University), Tomonori Totani (Kyoto
University) and Masahiro Nagashima (Nagasaki University) | Lyman Alpha Emitters in the Hierarchically Clustering Galaxy Formation | 14 pages, 7 figures, 1 table; accepted to ApJ; the html abstract is
replaced to match the accepted version, the .ps and .pdf files are strictly
identical between the 2nd and the 3rd versions | null | 10.1086/522200 | null | astro-ph | null | We present a new theoretical model for the luminosity functions (LFs) of
Lyman alpha (Lya) emitting galaxies in the framework of hierarchical galaxy
formation. We extend a semi-analytic model of galaxy formation that reproduces
a number of observations for local and high-z galaxies, without changing the
original model parameters but introducing a physically-motivated modelling to
describe the escape fraction of Lya photons from host galaxies (f_esc). Though
a previous study using a hierarchical clustering model simply assumed a
constant and universal value of f_esc, we incorporate two new effects on f_esc:
extinction by interstellar dust and galaxy-scale outflow induced as a star
formation feedback. It is found that the new model nicely reproduces all the
observed Lya LFs of the Lya emitters (LAEs) at different redshifts in z ~ 3-6.
Especially, the rather surprisingly small evolution of the observed LAE Lya LFs
compared with the dark halo mass function is naturally reproduced. Our model
predicts that galaxies with strong outflows and f_esc ~ 1 are dominant in the
observed LFs. This is also consistent with available observations, while the
simple universal f_esc model requires f_esc << 1 not to overproduce the
brightest LAEs. On the other hand, we found that our model significantly
overpredicts LAEs at z > 6, and absorption of Lya photons by neutral hydrogen
in intergalactic medium (IGM) is a reasonable interpretation for the
discrepancy. This indicates that the IGM neutral fraction x_HI rapidly evolves
from x_HI << 1 at z < 6 to a value of order unity at z ~ 6-7, which is broadly
consistent with other observational constraints on the reionization history.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 16:05:25 GMT"
},
{
"version": "v2",
"created": "Mon, 6 Aug 2007 13:12:19 GMT"
},
{
"version": "v3",
"created": "Tue, 7 Aug 2007 04:13:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kobayashi",
"Masakazu A. R.",
"",
"Kyoto University"
],
[
"Totani",
"Tomonori",
"",
"Kyoto\n University"
],
[
"Nagashima",
"Masahiro",
"",
"Nagasaki University"
]
] |
0705.4350 | Ken'ichiro Nakazato | Ken'ichiro Nakazato, Kohsuke Sumiyoshi and Shoichi Yamada | Numerical Study on Stellar Core Collapse and Neutrino Emission: Probe
into the Spherically Symmetric Black Hole Progenitors with 3 - 30Msun Iron
Cores | 33 pages, 13 figures, accepted by ApJ | Astrophys.J.666:1140-1151,2007 | 10.1086/520080 | WU-AP/258/06 | astro-ph | null | The existence of various anomalous stars, such as the first stars in the
universe or stars produced by stellar mergers, has been recently proposed. Some
of these stars will result in black hole formation. In this study, we
investigate iron core collapse and black hole formation systematically for the
iron-core mass range of 3 - 30Msun, which has not been studied well so far.
Models used here are mostly isentropic iron cores that may be produced in
merged stars in the present universe but we also employ a model that is meant
for a Population III star and is obtained by evolutionary calculation. We solve
numerically the general relativistic hydrodynamics and neutrino transfer
equations simultaneously, treating neutrino reactions in detail under spherical
symmetry. As a result, we find that massive iron cores with ~10Msun
unexpectedly produce a bounce owing to the thermal pressure of nucleons before
black hole formation. The features of neutrino signals emitted from such
massive iron cores differ in time evolution and spectrum from those of ordinary
supernovae. Firstly, the neutronization burst is less remarkable or disappears
completely for more massive models because the density is lower at the bounce.
Secondly, the spectra of neutrinos, except the electron type, are softer owing
to the electron-positron pair creation before the bounce. We also study the
effects of the initial density profile, finding that the larger the initial
density gradient is, the more steeply the neutronization burst declines.
Further more, we suggest a way to probe into the black hole progenitors from
the neutrino emission and estimate the event number for the currently operating
neutrino detectors.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 08:47:07 GMT"
}
] | 2010-05-12T00:00:00 | [
[
"Nakazato",
"Ken'ichiro",
""
],
[
"Sumiyoshi",
"Kohsuke",
""
],
[
"Yamada",
"Shoichi",
""
]
] |
0705.4351 | Wei Chao | Wei Chao | Neutrino Masses and Lepton-flavor-violating $\tau$ Decays in the
Supersymmetric Left-right Model | null | null | 10.1088/1674-1137/35/3/002 | null | hep-ph | null | In the supersymmetric left-right model, the light neutrino masses are given
by the Type-II seesaw mechanism. A duality property about this mechanism
indicates that there exist eight possible Higgs triplet Yukawa couplings which
result in the same neutrino mass matrix. In this paper, We work out the
one-loop renormalization group equations for the effective neutrino mass matrix
in the supersymmetric left-right model. The stability of the Type-II seesaw
scenario is briefly discussed. We also study the lepton-flavor-violating
processes ($\tau\to \mu\gamma$ and $\tau\to e\gamma$) by using the
reconstructed Higgs triplet Yukawa couplings.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 08:32:48 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Chao",
"Wei",
""
]
] |
0705.4352 | Wei Yi | W. Yi, G.-D. Lin, and L.-M. Duan | Signal of Bose condensation in an optical lattice at finite temperature | 4 pages, 2 figures, replaced with the published version | Phys. Rev. A 76, 031602(R) (2007) | 10.1103/PhysRevA.76.031602 | null | cond-mat.other | null | We discuss the experimental signal for the Bose condensation of cold atoms in
an optical lattice at finite temperature. Instead of using the visibility of
the interference pattern via the time-of-flight imaging, we show that the
momentum space density profile in the first Brillouin zone, in particular its
bimodal distribution, provides an unambiguous signal for the Bose condensation.
We confirm this point with detailed calculation of the change in the atomic
momentum distribution across the condensation phase transition, taking into
account both the global trapping potential and the atomic interaction effects.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:02:13 GMT"
},
{
"version": "v2",
"created": "Mon, 24 Sep 2007 11:41:06 GMT"
}
] | 2007-09-24T00:00:00 | [
[
"Yi",
"W.",
""
],
[
"Lin",
"G. -D.",
""
],
[
"Duan",
"L. -M.",
""
]
] |
0705.4353 | Leonid Golinskii | Leonid Golinskii and Mikhail Kudryavtsev | An inverse spectral theory for finite CMV matrices | LaTeX, 15 pages | null | null | null | math.SP math.CA | null | For finite dimensional CMV matrices the classical inverse spectral problems
are considered. We solve the inverse problem of reconstructing a CMV matrix by
its Weyl's function, the problem of reconstructing the matrix by two spectra of
CMV matrices with different "boundary conditions", and the problem of
reconstructing the CMV matrix by its spectrum and the spectrum of the CMV
matrix obtained from it by truncation.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 08:39:07 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Golinskii",
"Leonid",
""
],
[
"Kudryavtsev",
"Mikhail",
""
]
] |
0705.4354 | Wit | K. Fialkowski and R. Wit | On the new HERMES data for the electroproduction on nuclei | 5 pages, 3 figures, version to be published in the ISMD2007
proceedings in Acta Phys. Pol. B | Acta Phys.Polon.Supp.1:657-662,2008 | null | null | hep-ph | null | We analyze recent data on the electroproduction of hadrons on nuclei using
the Lund model for electroproduction on nucleons and a simple geometrical model
for the absorption effects. We show that the model seems to overestimate the
A-dependence of the absorption effects, although it described the earlier data
of the same HERMES experiment reasonably well. We trace the origin of this
discrepancy to the surprising difference between the data for nitrogen and
neon.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 08:50:27 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Dec 2007 10:16:19 GMT"
}
] | 2009-04-24T00:00:00 | [
[
"Fialkowski",
"K.",
""
],
[
"Wit",
"R.",
""
]
] |
0705.4355 | Tianxing Ma | Tianxing Ma | Resonant spin polarization in a two-dimensional hole gas: Effect of the
Luttinger term, structural inversion asymmetry and Zeeman splitting | 6 pages, 5 figures, content added | null | null | null | cond-mat.mes-hall | null | The electric-field-induced resonant spin polarization of a two-dimensional
hole gas described by Luttinger Hamiltonian with structural inversion asymmetry
and Zeeman splitting in a perpendicular magnetic field was studied. The spin
polarization arising from splitting between the light and the heavy hole bands
shows a resonant peak at a certain magnetic field. Especially, the competition
between the Luttinger term and the structural inversion asymmetry leads to a
rich resonant peaks structure, and the required magnetic field for the
resonance may be effectively reduced by enlarging the effective width of the
quantum well. Furthermore, the Zeeman splitting tends to move the resonant spin
polarization to a relative high magnetic field and destroy these rich resonant
spin phenomena. Finally, both the height and the weight of the resonant peak
increase as the temperature decreases. It is believed that such resonant spin
phenomena can be verified in the sample of a two-dimensional hole gas, and it
may provide an efficient way to control spin polarization by an external
electric field.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 08:55:05 GMT"
},
{
"version": "v2",
"created": "Tue, 9 Oct 2007 21:37:40 GMT"
}
] | 2007-10-10T00:00:00 | [
[
"Ma",
"Tianxing",
""
]
] |
0705.4356 | Istvan Montvay | I. Montvay | Monte Carlo Methods in Quantum Field Theory | 34 pages, 5 figures; Lectures given at Spring School on High Energy
Physics, Jaca, Spain, May 6-18, 2007 | null | null | DESY 07-076 | hep-lat | null | In these lecture notes some applications of Monte Carlo integration methods
in Quantum Field Theory - in particular in Quantum Chromodynamics - are
introduced and discussed.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 09:00:06 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Montvay",
"I.",
""
]
] |
0705.4357 | Bodo Geyer | B.Geyer and O. Witzel | Heavy Meson Distribution Amplitudes of Definite Geometric Twist with
Contribution of 3-Particle Distribution Amplitudes | 24 pages | Phys.Rev.D76:074022,2007 | 10.1103/PhysRevD.76.074022 | HU-EP-07/19, SFB/CPP-07-23 | hep-ph | null | Under the constraints of HQET the equations of motion of heavy meson
distribution amplitudes of definite geometric twist, using the knowledge of
their off-cone structure, are reformulated as a set of algebraic equations.
Together with equations due to various Dirac structures various relations
between the (sets of) independent two- and three particle distribution
amplitudes of definite geometric twist are derived and presented using both the
notion of (double) Mellin moments and re-summed non-local distribution
amplitudes. Resolving these relations for the independent two-particle moments
in terms of three-particle double moments we confirmed the representation of
$\Phi_{\pm|n}$ by Kawamura et al. (Phys. Lett. B \bf{523} (2001) 111).
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 09:00:21 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jul 2007 09:27:51 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Geyer",
"B.",
""
],
[
"Witzel",
"O.",
""
]
] |
0705.4358 | Anirban Saha | Pradip Mukherjee, Anirban Saha | Gauge invariances vis-{\'a}-vis Diffeomorphisms in second order metric
gravity: A new Hamiltonian approach | 6 Pages, revTex, paper modified substantially | Int.J.Mod.Phys.A24:4305-4315,2009 | 10.1142/S0217751X09044759 | null | hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A new analysis of the gauge invariances and their unity with diffeomorphism
invariances in second order metric gravity is presented which strictly follows
Dirac's constrained Hamiltonian approach.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 09:02:29 GMT"
},
{
"version": "v2",
"created": "Tue, 12 Feb 2008 16:16:51 GMT"
},
{
"version": "v3",
"created": "Mon, 16 Jun 2008 09:12:43 GMT"
}
] | 2009-09-25T00:00:00 | [
[
"Mukherjee",
"Pradip",
""
],
[
"Saha",
"Anirban",
""
]
] |
0705.4359 | Walter Petry | Walter Petry | Is the universe really expanding | 5 Pages, no figures | null | null | null | physics.gen-ph | null | The redshift of galaxies is in general explained by the expansion of space.
The flat space time theory of gravitation suggests an additional
interpretation. In this theory gravitation is explained analogously to
Maxwell's theory on a flat space-time metric and gravitation is described by a
field (potentials) with which the proper time (atomic time) is defined. In
addition to the proper time in the universe, the oberserver's time is stated.
The oberserver's time interval is absolute whereas the interval of the proper
time is time dependent. In particular, atomic clocks at distant objects are
going slower than clocks at present. This explains the redshift of distant
objects without assuming an expanding universe.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 09:10:13 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Petry",
"Walter",
""
]
] |
0705.4360 | Alastair Kay | Alastair Kay | Bounding Fault-Tolerant Thresholds for Purification and Quantum
Computation | 8 pages, 6 figures. published version | Phys. Rev. A 77, 052319 (2008) | 10.1103/PhysRevA.77.052319 | null | quant-ph | null | In this paper, we place bounds on when it is impossible to purify a noisy
two-qubit state if all the gates used in the purification protocol are subject
to adversarial local, independent, noise. It is found that the gate operations
must be subject to less than 5.3% error. An existing proof that purification is
equivalent to error correction is used to show that this bound can also be
applied to concatenated error correcting codes in the presence of noisy gates,
and hence gives a limit to the tolerable error rate for a fault-tolerant
quantum computer formed by concatenation. This is shown to apply also to the
case where error detection and post-selection, as proposed by Knill, is used to
enhance the threshold. We demonstrate the trade-off between
gate/environmentally induced faulty rotations and qubit loss errors.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 14:44:47 GMT"
},
{
"version": "v2",
"created": "Mon, 18 Jun 2007 09:33:55 GMT"
},
{
"version": "v3",
"created": "Fri, 12 Oct 2007 15:41:18 GMT"
},
{
"version": "v4",
"created": "Tue, 20 May 2008 06:42:04 GMT"
}
] | 2008-05-20T00:00:00 | [
[
"Kay",
"Alastair",
""
]
] |
0705.4361 | Evgeny Plekhanov | E. Plekhanov, A. Avella, and F. Mancini | Frustration-driven QPT in the 1D extended anisotropic Heisenberg model | 4 pages, 4 figures, to be presented at CSMAG-07 Kosice, Slovakia,
July 2007 | Acta Phys. Pol. A 113, 429 (2008) | 10.12693/APhysPolA.113.429 | null | cond-mat.str-el cond-mat.mes-hall quant-ph | null | By using Density Matrix Renormalization Group (DMRG) technique we study the
1D extended anisotropic Heisenberg model. We find that starting from the
ferromagnetic phase, the system undergoes two quantum phase transitions (QPTs)
induced by frustration. By increasing the next-nearest-neighbor (NNN)
interaction, the ground state of the system changes smoothly from a completely
polarized state to a NNN correlated one. On the contrary, letting the in-plane
interaction to be greater than the out-of-plane one, the ground state changes
abruptly.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 15:48:42 GMT"
}
] | 2018-04-09T00:00:00 | [
[
"Plekhanov",
"E.",
""
],
[
"Avella",
"A.",
""
],
[
"Mancini",
"F.",
""
]
] |
0705.4362 | Alexander Sakhnovich | Lev Sakhnovich | Explicit Rational Solutions of Knizhnik-Zamolodchikov Equation | null | Cent. Eur. J. Math. 6 (2008) 179-187 | null | null | math.CA math-ph math.MP | null | We consider the Knizhnik-Zamolodchikov system of linear differential
equations. The coefficients of this system are rational functions generated by
elements of the symmetric group $S_{n}$. We assume that parameter
$\rho=\pm{1}$. In previous paper we proved that the fundamental solution of the
corresponding KZ-equation is rational. Now we construct this solution in the
explicit form.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 09:35:31 GMT"
}
] | 2011-04-05T00:00:00 | [
[
"Sakhnovich",
"Lev",
""
]
] |
0705.4363 | Andrey Tsiganov | N.A. Kostov, A.V. Tsiganov | New Lax pair for restricted multiple three wave interaction system,
quasiperiodic solutions and bi-hamiltonian structure | 8 pages, revtex4, corrected typos | Regular and Chaotic Dynamics, v.13, n.6, pp. 593-601, 2008 | 10.1134/S1560354708060099 | null | nlin.SI | null | We study restricted multiple three wave interaction system by the inverse
scattering method. We develop the algebraic approach in terms of classical
$r$-matrix and give an interpretation of the Poisson brackets as linear
$r$-matrix algebra. The solutions are expressed in terms of polynomials of
theta functions. In particular case for $n=1$ in terms of Weierstrass
functions.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 09:43:29 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 10:49:58 GMT"
}
] | 2010-06-22T00:00:00 | [
[
"Kostov",
"N. A.",
""
],
[
"Tsiganov",
"A. V.",
""
]
] |
0705.4364 | Narciso Roman-Roy | Narciso Roman-Roy, Angel M. Rey, Modesto Salgado, Silvia Vilarino | On the k-Symplectic, k-Cosymplectic and Multisymplectic Formalisms of
Classical Field Theories | 25 pages | J. Geom. Mech. 3(1) (2011) 113177 | 10.3934/jgm.2011.3.113 | null | math-ph math.MP | null | The objective of this work is twofold: First, we analyze the relation between
the k-cosymplectic and the k-symplectic Hamiltonian and Lagrangian formalisms
in classical field theories. In particular, we prove the equivalence between
k-symplectic field theories and the so-called autonomous k-cosymplectic field
theories, extending in this way the description of the symplectic formalism of
autonomous systems as a particular case of the cosymplectic formalism in
non-autonomous mechanics. Furthermore, we clarify some aspects of the geometric
character of the solutions to the Hamilton-de Donder-Weyl and the
Euler-Lagrange equations in these formalisms. Second, we study the equivalence
between k-cosymplectic and a particular kind of multisymplectic Hamiltonian and
Lagrangian field theories (those where the configuration bundle of the theory
is trivial).
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 10:29:42 GMT"
}
] | 2015-12-15T00:00:00 | [
[
"Roman-Roy",
"Narciso",
""
],
[
"Rey",
"Angel M.",
""
],
[
"Salgado",
"Modesto",
""
],
[
"Vilarino",
"Silvia",
""
]
] |
0705.4365 | Hai Fu | Hai Fu, Alan Stockton (IfA Hawaii) | Integral Field Spectroscopy of the Extended Emission-Line Region of 4C
37.43 | Accepted by ApJ. 13 pages including 6 figures and 3 tables | Astrophys.J.666:794-805,2007 | 10.1086/520530 | null | astro-ph | null | We present Gemini integral field spectroscopy and Keck II longslit
spectroscopy of the extended emission-line region (EELR) around the quasar 4C
37.43. The velocity structure of the ionized gas is complex and cannot be
explained globally by a simple dynamical model. The spectra from the clouds are
inconsistent with shock or ``shock + precursor'' ionization models, but they
are consistent with photoionization by the quasar nucleus. The best-fit
photoionization model requires a low-metallicity (12+log(O/H) < 8.7) two-phase
medium, consisting of a matter-bounded diffuse component with a unity
filling-factor (N ~ 1 \cc, T ~ 15000 K), in which are embedded small, dense
clouds (N ~ 400 \cc, T ~ 10^4 K). The high-density clouds are transient and can
be re-generated through compressing the diffuse medium by low-speed shocks (V_S
\lesssim 100 \kms). Our photoionization model gives a total mass for the
ionized gas of about 3x10^{10} M_sun, and the total kinetic energy implied by
this mass and the observed velocity field is ~2x10^{58} ergs. The fact that
luminous EELRs are confined to steep-spectrum radio-loud quasars, yet show no
morphological correspondence to the radio jets, suggests that the driving force
producing the 4C 37.43 EELR was a roughly spherical blast wave initiated by the
production of the jet. That such a mechanism seems capable of ejecting a mass
comparable to that of the total interstellar medium of the Milky Way suggests
that ``quasar-mode'' feedback may indeed be an efficient means of regulating
star formation in the early universe.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 11:00:52 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Fu",
"Hai",
"",
"IfA Hawaii"
],
[
"Stockton",
"Alan",
"",
"IfA Hawaii"
]
] |
0705.4366 | Pierre-Henri Chavanis | Pierre-Henri Chavanis and Clement Sire | Critical mass of bacterial populations in a generalized Keller-Segel
model. Analogy with the Chandrasekhar limiting mass of white dwarf stars | null | Physica A, 387, 1999 (2008) | 10.1016/j.physa.2007.10.075 | null | cond-mat.stat-mech | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We point out a remarkable analogy between the limiting mass of white dwarf
stars (Chandrasekhar's limit) and the critical mass of bacterial populations in
a generalized Keller-Segel model of chemotaxis [Chavanis & Sire, PRE, 69,
016116 (2004)]. This model is based on generalized stochastic processes leading
to the Tsallis statistics. The equilibrium states correspond to polytropic
configurations similar to gaseous polytropes in astrophysics. For the critical
index n_3=d/(d-2) (where d is the dimension of space), the theory of polytropes
leads to a unique value of the mass M_c that we interpret as a limiting mass.
In d=3, we find M_c=202.8956... and in d=2, we recover the well-known result
M_c=8 pi (in suitable units). For M<M_c, the system evaporates (in an infinite
domain) or tends to an equilibrium state (for box-confined configurations). For
M>M_c, the system collapses and forms a Dirac peak containing a mass M_c
surrounded by a halo. This paper exposes the model and shows, by simple
considerations, the origin of the critical mass. A detailed description of the
critical dynamics of the generalized Keller-Segel model will be given in a
forthcoming paper.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 11:23:14 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Nov 2008 17:05:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Chavanis",
"Pierre-Henri",
""
],
[
"Sire",
"Clement",
""
]
] |
0705.4367 | Thorsten Kuhl | Thorsten Kuhl | Beauty and Charm Production Measurements at the Tevatron | Comments: 4 pages 6 figures, presented at XLIrst Rencontres de
Moriond on ``QCD and High Energy Hadronic Interactions'', La Thuile, Italy,
March 18-25, 2006, on behalf of the CDF and D0 collaborations | null | null | null | hep-ex | null | Results for the production of charm and beauty quarks in proton anti-proton
collisions at ECM=1.96 TeV (Tevatron) with the two multi purpose experiments
CDF and D0 using an integrated luminosity of up to 1 fb^-1 are presented. With
the data measurement of the production me chanism for charm and beauty quarks
are done. These measurements are leading to a better understanding of the QCD
in the transition region between pertubative a nd nonpertubative QCD. The
charm-charm angular correlation is measured with D me sons at the CDF
experiment. The Quarkonium production for charm and beauty final state at D0
and CDF is discussed.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 11:09:54 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Kuhl",
"Thorsten",
""
]
] |
0705.4368 | Robert Brownlee | R. A. Brownlee, E. H. Georgoulis, J. Levesley | Extending the range of error estimates for radial approximation in
Euclidean space and on spheres | 10 pages | SIAM J. Math. Anal., 39(2):554-564, 2007 | 10.1137/060650428 | MA-06-003, University of Leicester, UK | math.NA | null | We adapt Schaback's error doubling trick [R. Schaback. Improved error bounds
for scattered data interpolation by radial basis functions. Math. Comp.,
68(225):201--216, 1999.] to give error estimates for radial interpolation of
functions with smoothness lying (in some sense) between that of the usual
native space and the subspace with double the smoothness. We do this for both
bounded subsets of R^d and spheres. As a step on the way to our ultimate goal
we also show convergence of pseudoderivatives of the interpolation error.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 16:39:12 GMT"
}
] | 2007-12-02T00:00:00 | [
[
"Brownlee",
"R. A.",
""
],
[
"Georgoulis",
"E. H.",
""
],
[
"Levesley",
"J.",
""
]
] |
0705.4369 | Jean-Michel Muller | Peter Kornerup (IMADA), Vincent Lef\`evre (LIP), Jean-Michel Muller
(LIP) | Computing Integer Powers in Floating-Point Arithmetic | Laboratoire LIP : CNRS/ENS Lyon/INRIA/Universit\'e Lyon 1 | null | null | null | cs.NA cs.MS | null | We introduce two algorithms for accurately evaluating powers to a positive
integer in floating-point arithmetic, assuming a fused multiply-add (fma)
instruction is available. We show that our log-time algorithm always produce
faithfully-rounded results, discuss the possibility of getting correctly
rounded results, and show that results correctly rounded in double precision
can be obtained if extended-precision is available with the possibility to
round into double precision (with a single rounding).
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 11:34:39 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Kornerup",
"Peter",
"",
"IMADA"
],
[
"Lefèvre",
"Vincent",
"",
"LIP"
],
[
"Muller",
"Jean-Michel",
"",
"LIP"
]
] |
0705.4370 | Jacek Jezierski | Jacek Jezierski | Asymptotic conformal Yano-Killing tensors for asymptotic anti-de Sitter
spacetimes and conserved quantities | 38 pages | Acta Phys.Polon.B39:75-114,2008 | null | null | gr-qc | null | Conformal rescaling of conformal Yano--Killing tensors and relations between
Yano and CYK tensors are discussed. Pullback of these objects to a submanifold
is used to construct all solutions of a CYK equation in anti-de Sitter and de
Sitter spacetimes. Properties of asymptotic conformal Yano--Killing tensors are
examined for asymptotic anti-de Sitter spacetimes. Explicit asymptotic forms of
them are derived. The results are used to construct asymptotic charges in
asymptotic AdS spacetime. Well known examples like Schwarzschild-AdS, Kerr-AdS
and NUT-AdS are examined carefully in the construction of the concept of
energy, angular momentum and dual mass in asymptotic AdS spacetime.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 11:48:53 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Jezierski",
"Jacek",
""
]
] |
0705.4371 | Robert Brownlee | R. A. Brownlee, A. N. Gorban, J. Levesley | Stable simulation of fluid flow with high-Reynolds number using
Ehrenfests' steps | 21 pages, 2 figures | null | 10.1007/s11075-007-9087-1 | MA-07-06, University of Leicester, UK | cond-mat.stat-mech | null | The Navier--Stokes equations arise naturally as a result of Ehrenfests'
coarse-graining in phase space after a period of free-flight dynamics. This
point of view allows for a very flexible approach to the simulation of fluid
flow for high-Reynolds number. We construct regularisers for lattice Boltzmann
computational models. These regularisers are based on Ehrenfests'
coarse-graining idea and could be applied to schemes with either entropic or
non-entropic quasiequilibria. We give a numerical scheme which gives good
results for the standard test cases of the shock tube and the flow past a
square cylinder.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 16:40:04 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Brownlee",
"R. A.",
""
],
[
"Gorban",
"A. N.",
""
],
[
"Levesley",
"J.",
""
]
] |
0705.4372 | Kjell Tangen | Kjell Tangen | Generating Minimally Coupled Einstein-Scalar Field Solutions from Vacuum
Solutions with Arbitrary Cosmological Constant | 23 pages, 4 figures. v2: Replaced figures, more details on the
example solution in section VII.B | null | null | null | gr-qc | null | This paper generalizes two previously known techniques for generating
minimally coupled Einstein-scalar field solutions in 4 dimensions; the Buchdahl
and Fonarev transformations. By applying this solution generation technique,
minimally coupled Einstein-scalar field solutions can be generated from vacuum
solutions with arbitrary cosmological constant in arbitrary dimension. The only
requirement to a seed solution is that it posesses a hypersurface-orthogonal
Killing vector field. The generalization that allows us to use seed solutions
with arbitrary cosmological constant uncovers a new class of Einstein-scalar
field solutions that has previously not been studied. We apply the new solution
transformation to the (A)dS4 vacuum solution. Transforming the resulting
Einstein-scalar field solution to the conformal frame, a two-parameter family
of spatially finite, expanding and accelerating cosmological solutions are
found that are conformally isometric to the Einstein static universe RxS^3. We
study null geodesics and find that for any observer, the solution has a
cosmological horizon at an angular distance of pi/2 away from the observer. We
find that a subset of these solutions can be naturally interpreted as expanding
cosmologies in which a scalar black hole is formed at late times. The
conformally coupled scalar field satisfies the weak energy condition as long as
the energy density is positive, while the strong energy condition is generally
violated.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 15:45:49 GMT"
},
{
"version": "v2",
"created": "Mon, 4 Jun 2007 11:22:27 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Tangen",
"Kjell",
""
]
] |
0705.4373 | Faisal El-Orany Dr. | Faisal A. A. El-Orany | Relationship between the linear entropy, the von Neumann entropy and the
atomic Wehrl entropy for the Jaynes-Cummings model | 10 pages, 1 figure, comments are most welcome | null | null | null | quant-ph | null | The linear entropy, the von Neumann entropy and the atomic Wehrl entropy are
frequently used to quantify entanglement in the quantum systems. These
relations provide typical information on the entanglement in the
Jaynes-Cummings model (JCM). In this Letter, we explain the origin of this
analytically and derive a closed form for the atomic Wehrl entropy. Moreover,
we show that it is more convenient to use the Bloch sphere radius for
quantifying entanglement in the JCM instead of these entropic relations.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:01:17 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"El-Orany",
"Faisal A. A.",
""
]
] |
0705.4374 | Robert Brownlee | R. A. Brownlee, P. Houston, J. Levesley, S. Rosswog | Enhancing SPH using moving least-squares and radial basis functions | 10 pages, 3 figures, In Proc. A4A5, Chester UK, Jul. 18-22 2005 | Algorithms for Approximation: Proceedings of the 5th International
Conference, Chester UK, July 18-22 2005, pages 103-112, Springer, 2007 | 10.1007/978-3-540-46551-5_8 | MA-06-001, University of Leicester, UK | math.NA | null | In this paper we consider two sources of enhancement for the meshfree
Lagrangian particle method smoothed particle hydrodynamics (SPH) by improving
the accuracy of the particle approximation. Namely, we will consider shape
functions constructed using: moving least-squares approximation (MLS); radial
basis functions (RBF). Using MLS approximation is appealing because polynomial
consistency of the particle approximation can be enforced. RBFs further appeal
as they allow one to dispense with the smoothing-length -- the parameter in the
SPH method which governs the number of particles within the support of the
shape function. Currently, only ad hoc methods for choosing the
smoothing-length exist. We ensure that any enhancement retains the conservative
and meshfree nature of SPH. In doing so, we derive a new set of
variationally-consistent hydrodynamic equations. Finally, we demonstrate the
performance of the new equations on the Sod shock tube problem.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 16:37:09 GMT"
}
] | 2007-12-02T00:00:00 | [
[
"Brownlee",
"R. A.",
""
],
[
"Houston",
"P.",
""
],
[
"Levesley",
"J.",
""
],
[
"Rosswog",
"S.",
""
]
] |
0705.4375 | Dieter Koelle | D. Doenitz, R. Kleiner, D. Koelle, T. Scherer, K. F. Schuster | Imaging of Thermal Domains in ultrathin NbN films for Hot Electron
Bolometers | 3 pages, 3 figures | null | 10.1063/1.2751109 | null | cond-mat.supr-con | null | We present low-temperature scanning electron microscopy (LTSEM)
investigations of superconducting microbridges made from ultrathin NbN films as
used for hot electron bolometers. LTSEM probes the thermal structure within the
microbridges under various dc current bias conditions, either via
electron-beam-induced generation of an unstable hotspot, or via the
beam-induced growth of a stable hotspot. Such measurements reveal
inhomogeneities on a micron scale, which may be due to spatial variations in
the NbN film or film-interface properties. Comparison with model calculations
for the stable hotspot regime confirm the basic features of common hot spot
models.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:14:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Doenitz",
"D.",
""
],
[
"Kleiner",
"R.",
""
],
[
"Koelle",
"D.",
""
],
[
"Scherer",
"T.",
""
],
[
"Schuster",
"K. F.",
""
]
] |
0705.4376 | Pinaki Roy | R.Roychoudhury and P.Roy | Construction of C operator for a PT symmetric model | To appear in J.Phys A | null | null | null | quant-ph | null | We obtain closed form expression of the C(x,y) operator for the PT symmetric
Scarf I potential. It is also shown that the eigenfunctions are complete.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:17:38 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Roychoudhury",
"R.",
""
],
[
"Roy",
"P.",
""
]
] |
0705.4377 | Astrakharchik Grigori E | F. Mazzanti, G. E. Astrakharchik, J. Boronat, and J. Casulleras | Ground-State Properties of a One-Dimensional System of Hard Rods | 4 pages, 4 figures | null | 10.1103/PhysRevLett.100.020401 | null | cond-mat.other | null | A quantum Monte Carlo simulation of a system of hard rods in one dimension is
presented and discussed. The calculation is exact since the analytical form of
the wavefunction is known, and is in excellent agreement with predictions
obtained from asymptotic expansions valid at large distances. The analysis of
the static structure factor and the pair distribution function indicates that a
solid-like and a gas-like phases exist at high and low densities, respectively.
The one-body density matrix decays following a power-law at large distances and
produces a divergence in the low density momentum distribution at k=0 which can
be identified as a quasi-condensate.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 15:46:08 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Mazzanti",
"F.",
""
],
[
"Astrakharchik",
"G. E.",
""
],
[
"Boronat",
"J.",
""
],
[
"Casulleras",
"J.",
""
]
] |
0705.4378 | Alejandro Gangui | Jos\'e X. Martini | Einstein and early 20th Century avant-garde art: points of contact? | 9 pages, Published in Spanish in "El universo de Einstein: 1905 -
annus mirabilis - 2005", Alejandro Gangui (ed.), Editorial EUDEBA, 2007
(arXiv:0705.4266). Also available at http://www.universoeinstein.com.ar/ | null | null | UEinstein/2007/29 | physics.hist-ph physics.pop-ph | null | Art history linked some early 20th Century avant-garde visual art movements
to contemporary systems of ideas in mathematics and theoretical physics. One of
the proposed connections is the one that might have existed between Cubism and
Relativity, or more precisely, between Picasso and Einstein. The suggested
links are similarity (in a weak version) or identity (in a strong version) in
matters of space, time and simultaneity. It is possible, however, that these
supposed links of Einstein and avant-garde art movements were more the product
of the imagination of historians and critics, than the result of connections
between painters and scientists. On the one hand, the visual arts (in contrast
to music, as far as we now) were of no interest to Einstein, who, moreover, did
not seem inclined or knowledgeable enough to appreciate advanced forms. On the
other hand, Einstein's theories fell outside the artists' ken, let alone their
understanding, although there are firm clues pointing to the fact that
repercussions of those theories in the press and in literary circles could have
fired the imagination of some artists.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:27:28 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Martini",
"José X.",
""
]
] |
0705.4379 | Claude Ederer | Claude Ederer, Chungwei Lin, and Andrew J. Millis | Structural distortions and model Hamiltonian parameters: from LSDA to a
tight-binding description of LaMnO_3 | replaced with final (published) version with improved presentation | Phys. Rev. B 76, 155105 (2007) | 10.1103/PhysRevB.76.155105 | null | cond-mat.str-el cond-mat.mtrl-sci | null | The physics of manganites is often described within an effective two-band
tight-binding (TB) model for the Mn e_g electrons, which apart from the kinetic
energy includes also a local "Hund's rule" coupling to the t_{2g} core spin and
a local coupling to the Jahn-Teller (JT) distortion of the oxygen octahedra. We
test the validity of this model by comparing the energy dispersion calculated
for the TB model with the full Kohn-Sham band-structure calculated within the
local spin-density approximation (LSDA) to density functional theory. We
analyze the effect of magnetic order, JT distortions, and "GdFeO_3-type"
tilt-rotations of the oxygen octahedra. We show that the hopping amplitudes are
independent of magnetic order and JT distortions, and that both effects can be
described with a consistent set of model parameters if hopping between both
nearest and next-nearest neighbors is taken into account. We determine a full
set of model parameters from the density functional theory calculations, and we
show that both JT distortions and Hund's rule coupling are required to obtain
an insulating ground state within LSDA. Furthermore, our calculations show that
the "GdFeO_3-type" rotations of the oxygen octahedra lead to a substantial
reduction of the hopping amplitudes but to no significant deviation from the
simple TB model.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:32:46 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Jun 2008 18:08:35 GMT"
}
] | 2008-06-03T00:00:00 | [
[
"Ederer",
"Claude",
""
],
[
"Lin",
"Chungwei",
""
],
[
"Millis",
"Andrew J.",
""
]
] |
0705.4380 | Bobomurat Ahmedov | U.A. Mofiz and B.J. Ahmedov | Plasma Modes Along the Open Field Lines of a Neutron Star | null | Astrophys.J.542:484-492,2000 | 10.1086/309496 | null | astro-ph gr-qc | null | We consider electrostatic plasma modes along the open field lines of a
rotating neutron star. Goldreich-Julian charge density in general relativity is
analyzed for the neutron star with zero inclination. It is found that the
charge density is maximum at the polar cap and it remains almost same in
certain extended region of the pole. For a steady state Goldreich-Julian charge
density we found the usual plasma oscillation along the field lines; plasma
frequency resembles to the gravitational redshift close to the Schwarzschild
radius. We study the nonlinear plasma mode along the field lines. From the
system of equations under general relativity, a second order differential
equation is derived. The equation contains a term which describes the growing
plasma modes near Schwarzschild radius in a black hole environment. The term
vanishes with the distance far away from the gravitating object. For initially
zero potential and field on the surface of a neutron star, Goldreich-Julian
charge density is found to create the plasma mode, which is enhanced and
propagates almost without damping along the open field lines. We briefly
outline our plan to extend the work for studying soliton propagation along the
open field lines of strongly gravitating objects.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:38:02 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Mofiz",
"U. A.",
""
],
[
"Ahmedov",
"B. J.",
""
]
] |
0705.4381 | Mu-In Park | Mu-in Park | Holography in Three-dimensional Kerr-de Sitter Space with a
Gravitational Chern-Simons Term | Typos corrected; Accepted in CQG | Class.Quant.Grav.25:135003,2008 | 10.1088/0264-9381/25/13/135003 | null | hep-th astro-ph gr-qc | null | The holographic description of the three-dimensional Kerr-de Sitter space
with a gravitational Chern-Simons term is studied, in the context of dS/CFT
correspondence. The space has only one (cosmological) event horizon and its
mass and angular momentum are identified from the holographic energy-momentum
tensor at the asymptotic infinity. The thermodynamic entropy of the
cosmological horizon is computed directly from the first law of thermodynamics,
with the usual Hawking temperature, and it is found that the usual
Gibbons-Hawking entropy is modified. It is remarked that, due to the
gravitational Chern-Simons term, (a) the results go beyond analytic
continuation from AdS, (b) the maximum-mass/N-bound conjecture may be violated,
and (c) the three-dimensional cosmology is chiral. A statistical mechanical
computation of the entropy, from a Cardy-like formula for a dual CFT at the
asymptotic boundary, is discussed. Some technical difference in the
Chern-Simons energy-momentum tensor, from literatures is remarked also.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:49:00 GMT"
},
{
"version": "v2",
"created": "Sat, 2 Jun 2007 12:11:49 GMT"
},
{
"version": "v3",
"created": "Fri, 9 Nov 2007 11:41:51 GMT"
},
{
"version": "v4",
"created": "Sat, 17 May 2008 01:29:01 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Park",
"Mu-in",
""
]
] |
0705.4382 | T.R.S. Prasanna | T.R.S. Prasanna | Analysis of long range order | revised manuscript, 31 pages, submitted for publication | null | null | null | cond-mat.mtrl-sci cond-mat.str-el | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A first principles analysis of order-disorder transition in alloys shows that
ordering energy is a function of temperature due to thermal vibrations. The
inter-nuclear potential energy term converges if zero point vibrations are
incorporated and this method can replace the Ewald sum method. Core energy
contributions to the ordering energy are stored exclusively in superlattice
lines. The effect of electron-phonon interactions on ordering energy is of the
same order of magnitude as ordering energy near transition temperatures and
cannot be ignored. Ising model and variants are incorrect in explaining alloy
phase transitions as they ignore the role of electron-phonon interactions
without justification. A theoretical formalism that incorporates the
Debye-Waller Factor component of electron-phonon interactions in electronic
structure calculations already exists and must be adopted when modeling
temperature dependent phenomena. It is suggested that DWF correction will
account substantially for the discrepancy between experimental and theoretical
ordering energy in Ni3V. Thermal vibrations alter magnetic ordering energy at
finite temperatures. The role of electron-phonon interactions in alloy and
magnetic phase transitions cannot be ignored and must be incorporated in all
models. This will also ensure consistency with x-ray and electron diffraction
(alloy transitions) and neutron diffraction (magnetic transitions) results. An
isotope effect is predicted for (magnetic) phase transitions if the transition
temperature is below Debye temperature. Recent observations of an isotope
effect in magnetic phase transitions confirm our above conclusions and imply
that the role of electron-phonon interactions must be incorporated in all
theories and models of magnetism to avoid contradictions.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:42:54 GMT"
},
{
"version": "v2",
"created": "Sat, 8 Sep 2007 08:47:28 GMT"
},
{
"version": "v3",
"created": "Wed, 16 Apr 2008 12:54:30 GMT"
},
{
"version": "v4",
"created": "Thu, 29 May 2008 11:44:52 GMT"
},
{
"version": "v5",
"created": "Thu, 11 Sep 2008 09:27:34 GMT"
},
{
"version": "v6",
"created": "Mon, 3 Nov 2008 11:34:53 GMT"
},
{
"version": "v7",
"created": "Tue, 2 Dec 2008 10:48:46 GMT"
}
] | 2008-12-02T00:00:00 | [
[
"Prasanna",
"T. R. S.",
""
]
] |
0705.4383 | Yury Bystritskiy | E. A. Kuraev, V. N. Pervushin, M. K. Volkov | To a question on the \eta \to \pi^0 \gamma \gamma decay width in
meson-baryon chiral model | 4 pages, 1 pic | JETPLett.86:164-166,2007 | 10.1134/S0021364007150039 | null | hep-ph | null | It is shown in the work of one of the authors in 1979 (MKV) that the
contribution to the amplitude of this decay from diagrams with one baryon loop
is equal to zero and contributions from diagrams with meson loops appear very
small. However, pole diagrams with intermediate vector mesons were not
considered there. Here it is shown that contributions of these pole diagrams
dominate. The meson-baryon chiral model used here is compared with known quark
chiral models. The obtained results are in satisfactory agreement with recent
experimental data.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 12:53:17 GMT"
},
{
"version": "v2",
"created": "Sun, 24 Jun 2007 10:43:49 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kuraev",
"E. A.",
""
],
[
"Pervushin",
"V. N.",
""
],
[
"Volkov",
"M. K.",
""
]
] |
0705.4384 | Neda Sadooghi | N. Sadooghi and A. Sodeiri Jalili | A new look at the modified Coulomb potential in a strong magnetic field | V1: 26 pages, 8 figures, latex format, V2: Accepted for publication
in PRD (2007) | Phys.Rev.D76:065013,2007 | 10.1103/PhysRevD.76.065013 | SUT-P-2007/001b, IPM/P-2007/037 | hep-th | null | The static Coulomb potential of Quantum Electrodynamics (QED) is calculated
in the presence of a strong magnetic field in the lowest Landau level (LLL)
approximation using two different methods. First, the vacuum expectation value
of the corresponding Wilson loop is calculated perturbatively in two different
regimes of dynamical mass $m_{dyn.}$, {\it i.e.}, $|{\mathbf{q}}_{\|}^{2}|\ll
m_{dyn.}^{2}\ll |eB|$ and $m_{dyn.}^{2}\ll |\mathbf{q}_{\|}^{2}|\ll|eB|$, where
$\mathbf{q}_{\|}$ is the longitudinal components of the momentum relative to
the external magnetic field $B$. The result is then compared with the static
potential arising from Born approximation. Both results coincide. Although the
arising potentials show different behavior in the aforementioned regimes, a
novel dependence on the angle $\theta$ between the particle-antiparticle's axis
and the direction of the magnetic field is observed. In the regime
$|{\mathbf{q}}_{\|}^{2}|\ll m_{dyn.}^{2}\ll |eB|$, for strong enough magnetic
field and depending on the angle $\theta$, a qualitative change occurs in the
Coulomb-like potential; Whereas for $\theta=0,\pi$ the potential is repulsive,
it exhibits a minimum for angles $\theta\in]0,\pi[$.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 13:23:20 GMT"
},
{
"version": "v2",
"created": "Tue, 17 Jul 2007 09:50:42 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Sadooghi",
"N.",
""
],
[
"Jalili",
"A. Sodeiri",
""
]
] |
0705.4385 | Ralf Schutzhold | Ralf Sch\"utzhold, Gernot Schaller, and Dietrich Habs | Table-top creation of entangled multi-keV photon pairs via the Unruh
effect | 4 pages, 1 figure | null | 10.1103/PhysRevLett.100.091301 | null | quant-ph | null | Electrons moving in a strong periodic electromagnetic field (e.g., laser or
undulator) may convert quantum vacuum fluctuations into pairs of entangled
photons, which can be understood as a signature of the Unruh effect. Apart from
verifying this striking phenomenon, the considered effect may allow the
construction of a table-top source for entangled photons (``photon pair
laser'') and the associated quantum-optics applications in the multi-keV regime
with near-future facilities. 04.62.+v, 12.20.Fv, 41.60.-m, 42.50.Dv.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 13:02:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Schützhold",
"Ralf",
""
],
[
"Schaller",
"Gernot",
""
],
[
"Habs",
"Dietrich",
""
]
] |
0705.4386 | Hiroshi Kambara | H. Kambara, Y. Niimi, M. Ishikado, S. Uchida, and Hiroshi Fukuyama | Temperature dependence of the impurity-induced resonant state in
Zn-doped Bi_2Sr_2CaCu_2O$_{8+\delta}$ by Scanning Tunneling Spectroscopy | 4 pages, 3 figures, to appear in Phys. Rev. B | Phys. Rev. B 76, 052506 (2007). | 10.1103/PhysRevB.76.052506 | null | cond-mat.supr-con | null | We report on the temperature dependence of the impurity-induced resonant
state in Zn-doped Bi_2Sr_2CaCu_2O$_{8+\delta}$ by scanning tunneling
spectroscopy at 30 mK < T < 52 K. It is known that a Zn impurity induces a
sharp resonant peak in tunnel spectrum at an energy close to the Fermi level.
We observed that the resonant peak survives up to 52 K. The peak broadens with
increasing temperature, which is explained by the thermal effect. This result
provides information to understand the origin of the resonant peak.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 13:48:49 GMT"
},
{
"version": "v2",
"created": "Thu, 2 Aug 2007 09:45:49 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kambara",
"H.",
""
],
[
"Niimi",
"Y.",
""
],
[
"Ishikado",
"M.",
""
],
[
"Uchida",
"S.",
""
],
[
"Fukuyama",
"Hiroshi",
""
]
] |
0705.4387 | John F. Gunion | Radovan Dermisek and John F. Gunion | The NMSSM Solution to the Fine-Tuning Problem, Precision Electroweak
Constraints and the Largest LEP Higgs Event Excess | 26 pages, 37 figures, published version with minor text and reference
improvements | Phys.Rev.D76:095006,2007 | 10.1103/PhysRevD.76.095006 | null | hep-ph | null | We present an extended study of how the Next to Minimal
Supersymmetric Model easily avoids fine-tuning in electroweak symmetry
breaking for a SM-like light Higgs with mass in the vicinity of $100\gev$, as
beautifully consistent with precision electroweak data, while escaping LEP
constraints due to the dominance of $h\to aa$ decays with $m_a<2m_b$ so that
$a\to \tauptaum$ or jets. The residual $\sim 10%$ branching ratio for $h\to
b\anti b$ explains perfectly the well-known LEP excess at $\mh\sim 100\gev$.
Details of model parameter correlations and requirements are discussed as a
function $\tan(\beta)$. Comparisons of fine-tuning in the NMSSM to that in the
MSSM are presented. We also discuss fine-tuning associated with scenarios in
which the $a$ is essentially pure singlet, has mass $m_a>30\gev$, and decays
primarily to $\gam\gam$ leading to an $h\to aa\to 4\gam$ Higgs signal.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 00:14:04 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Sep 2007 13:02:04 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Dermisek",
"Radovan",
""
],
[
"Gunion",
"John F.",
""
]
] |
0705.4388 | Rafael Ferraro | Rafael Ferraro | From Newton to Einstein: the birth of Special Relativity | 12 pages, Published in Spanish in "El universo de Einstein: 1905 -
annus mirabilis - 2005", Alejandro Gangui (ed.), Editorial EUDEBA, 2007
(arXiv:0705.4266). Also available at http://www.universoeinstein.com.ar/ | null | null | UEinstein/2007/03 | physics.hist-ph physics.pop-ph | null | Physics was in crisis at the beginning of the twentieth century because the
newborn Maxwell's electromagnetism defied mechanistic preconceptions. Albert
Einstein understood that the solution to the crisis required an audacious
reworking of the concepts of space and time. Special Relativity deeply modified
our way of regarding space and time, in order to harmonize electromagnetism
with the principle of relativity. As a consequence, lengths and elapsed times
were stripped of the invariant character that classical Physics conferred them;
in their place, the speed of light acquired that privileged status. Such
revolutionary change forced Einstein to reformulate Newtonian mechanics, a step
that led him to discover the mass-energy equivalence.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 13:13:13 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Ferraro",
"Rafael",
""
]
] |
0705.4389 | Margherita Barile Prof. | Margherita Barile | On simplicial toric varieties of codimension 2 | Revised version. To appear in: Rendiconti dell'Istituto di Matematica
dell'Universita' di Trieste. Dedicated to the memory of Fabio Rossi | null | null | null | math.AC math.AG | null | We describe classes of toric varieties of codimension 2 which are either
minimally defined by 3 binomial equations over any algebraically closed field,
or are set-theoretic complete intersections in exactly one positive
characteristic.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 13:14:38 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 12:14:11 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Barile",
"Margherita",
""
]
] |
0705.4390 | Riad Nechache M. | Riad Nechache, Louis-Philippe Carignan, Lina Gunawan, Catalin
Harnagea, Gianluigi Botton, David Menard, and Alain Pignolet | Epitaxial thin films of multiferroic Bi2FeCrO6 with B-site cationic
order | Accepted for publication in Journal of Materials Research | null | 10.1557/jmr.2007.0273 | null | cond-mat.mtrl-sci | null | Epitaxial thin films of Bi2FeCrO6 have been synthesized by pulsed laser
deposition on SrRuO3 on (100)- and (111)-oriented SrTiO3 substrates. Detailed
X-ray diffraction and cross-section transmission electron microscopy analysis
revealed a double perovskite crystal structure of the Bi2FeCrO6 epitaxial films
very similar to that of BiFeO3 along with a particularly noteworthy Fe3+/Cr3+
cation ordering along the [111] direction. The films contain no detectable
magnetic iron oxide impurities and have the correct cationic average
stoichiometry throughout their thickness. They however exhibit a slight
modulation in the Fe and Cr compositions forming complementary stripe patterns,
suggesting minor local excess or depletion of Fe and Cr. The epitaxial BFCO
films exhibit good ferroelectric and piezoelectric properties, in addition to
magnetic properties at room temperature, as well as an unexpected
crystallographic orientation dependence of their room temperature magnetic
properties. Our results qualitatively confirm the predictions made using the
ab-initio calculations: the double-perovskite structure of Bi2FeCrO6 films
exhibit a Fe3+/Cr3+ cation ordering and good multiferroic properties, along
with the unpredicted existence of magnetic ordering at room temperature.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 13:22:39 GMT"
}
] | 2016-06-29T00:00:00 | [
[
"Nechache",
"Riad",
""
],
[
"Carignan",
"Louis-Philippe",
""
],
[
"Gunawan",
"Lina",
""
],
[
"Harnagea",
"Catalin",
""
],
[
"Botton",
"Gianluigi",
""
],
[
"Menard",
"David",
""
],
[
"Pignolet",
"Alain",
""
]
] |
0705.4391 | Roman Yusupov | R. V. Yusupov, V. V. Kabanov, D. Mihailovic, K. Conder, K. A. Mueller,
and H. Keller | Spontaneous ferromagnetic spin ordering at the surface of La$_2$CuO$_4$ | 10 pages, 15 figures | null | 10.1103/PhysRevB.76.024428 | null | cond-mat.str-el cond-mat.mtrl-sci cond-mat.supr-con | null | Magnetic properties of high purity stoichiometric La$_2$CuO$_4$ nanoparticles
are systematically investigated as a function of particle size. Ferromagnetic
single-domain spin clusters are shown to spontaneously form at the surface of
fine grains as well as paramagnetic defects. Hysteresis loops and
thermomagnetic irreversibility are observed in a wide temperature range $5 -
350$ K with the remnant moment and coercivity gradually decreasing with
increasing temperature. Possible origins of the spontaneous surface
ferromagnetic clusters and the relation of our data to the appearance of
unusual magnetic phenomena and phase separation of doped cuprates are
discussed.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 13:25:53 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Yusupov",
"R. V.",
""
],
[
"Kabanov",
"V. V.",
""
],
[
"Mihailovic",
"D.",
""
],
[
"Conder",
"K.",
""
],
[
"Mueller",
"K. A.",
""
],
[
"Keller",
"H.",
""
]
] |
0705.4392 | Bernd Kniehl | B.A. Kniehl, G. Kramer, I. Schienbein, H. Spiesberger | Finite-Mass Effects on Inclusive B-Meson Hadroproduction | 27 pages, 11 figures; comparison w/ preliminary CDF data included,
discussion extended, figure and references added; shown that familiar factor
3 between CDF data and "NLO QCD" is eliminated by using up-to-date PDF set
and alpha_s value; accepted for publication in Phys. Rev. D | Phys.Rev.D77:014011,2008 | 10.1103/PhysRevD.77.014011 | DESY 07-066, MZ-TH/07-07, LPSC 07-46 | hep-ph | null | We calculate the transverse-momentum (p_T) distribution for the inclusive
hadroproduction of B mesons at intermediate values of p_T at next-to-leading
order (NLO) in a dedicated finite-mass scheme using realistic non-perturbative
fragmentation functions that are obtained through a global fit to e^+e^- data
from CERN LEP1 and SLAC SLC exploiting their universality and scaling
violations. We find that finite-mass effects moderately enhance the cross
section, by about 20% at p_T = 2 m_b, and rapidly fade out with increasing
value of p_T, so that the zero-mass prediction is reached. We also perform
comparisons with recent ppbar data taken by the CDF Collaboration in run II at
the Fermilab Tevatron and comment on the usefulness of the fixed-flavor-number
scheme.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 13:26:09 GMT"
},
{
"version": "v2",
"created": "Thu, 29 Nov 2007 11:59:10 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kniehl",
"B. A.",
""
],
[
"Kramer",
"G.",
""
],
[
"Schienbein",
"I.",
""
],
[
"Spiesberger",
"H.",
""
]
] |
0705.4393 | Julien Grain | J. Grain, A. Barrau | Semiclassical scalar propagators in curved backgrounds: formalism and
ambiguities | New materials on gravitationally-induced quantum interferences has
been added | Phys.Rev.D76:084009,2007 | 10.1103/PhysRevD.76.084009 | null | hep-th astro-ph gr-qc hep-ph quant-ph | null | The phenomenology of quantum systems in curved space-times is among the most
fascinating fields of physics, allowing --often at the gedankenexperiment
level-- constraints on tentative theories of quantum gravity. Determining the
dynamics of fields in curved backgrounds remains however a complicated task
because of the highly intricate partial differential equations involved,
especially when the space metric exhibits no symmetry. In this article, we
provide --in a pedagogical way-- a general formalism to determine this dynamics
at the semiclassical order. To this purpose, a generic expression for the
semiclassical propagator is computed and the equation of motion for the
probability four-current is derived. Those results underline a direct analogy
between the computation of the propagator in general relativistic quantum
mechanics and the computation of the propagator for stationary systems in
non-relativistic quantum mechanics. A possible application of this formalism to
curvature-induced quantum interferences is also discussed.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 14:06:49 GMT"
},
{
"version": "v2",
"created": "Fri, 12 Oct 2007 15:04:49 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Grain",
"J.",
""
],
[
"Barrau",
"A.",
""
]
] |
0705.4394 | Jean-Marc Berroir | Gwendal F\`eve (LPA), Adrien Mah\'e (LPA), Jean-Marc Berroir (LPA),
Takis Kontos (LPA), Bernard Pla\c{c}ais (LPA), Christian Glattli (LPA, SPEC),
A. Cavanna (LPN), Bernard Etienne (LPN), Yong Jin (LPN) | An On-Demand Coherent Single Electron Source | null | Science 316 (2007) 1169 | 10.1126/science.1141243 | null | cond-mat.mes-hall | null | We report on the electron analog of the single photon gun. On demand single
electron injection in a quantum conductor was obtained using a quantum dot
connected to the conductor via a tunnel barrier. Electron emission is triggered
by application of a potential step which compensates the dot charging energy.
Depending on the barrier transparency the quantum emission time ranges from 0.1
to 10 nanoseconds. The single electron source should prove useful for the
implementation of quantum bits in ballistic conductors. Additionally periodic
sequences of single electron emission and absorption generate a quantized
AC-current.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 14:02:29 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Fève",
"Gwendal",
"",
"LPA"
],
[
"Mahé",
"Adrien",
"",
"LPA"
],
[
"Berroir",
"Jean-Marc",
"",
"LPA"
],
[
"Kontos",
"Takis",
"",
"LPA"
],
[
"Plaçais",
"Bernard",
"",
"LPA"
],
[
"Glattli",
"Christian",
"",
"LPA, SPEC"
],
[
"Cavanna",
"A.",
"",
"LPN"
],
[
"Etienne",
"Bernard",
"",
"LPN"
],
[
"Jin",
"Yong",
"",
"LPN"
]
] |
0705.4395 | Arrigo Calzolari | Arrigo Calzolari, Andrea Ferretti, and Marco Buongiorno Nardelli | Ab initio correlation effects on the electronic and transport properties
of metal(II)-phthalocyanine based devices | 12 pages, 5 figures. Nanotechnology (2007), in press | null | 10.1088/0957-4484/18/42/424013 | null | cond-mat.soft cond-mat.str-el | null | Using first principles calculations in the framework of Density Functional
Theory, we investigated the electronic and transport properties of
metal(II)-phthalocyanine (M(II)Pc) systems, both in a single molecule
configuration and in a model-device geometry. In particular, using the
Copper(II)- and Manganese(II)-Pc as prototypical examples, we studied how
electronic correlations on the central metal-ion influence the analysis of the
electronic structure of the system and we demonstrated that the choice of the
exchange-correlation functional, also beyond the standard local or gradient
corrected level, is of crucial importance for a correct interpretation of the
data. Finally, our electronic transport simulations have shown that
M(II)Pc-based devices can act selectively as molecular conductors, as in the
case of Copper, or as spin valves, as in the case of Manganese, demonstrating
once more the great potential of these systems for molecular nanoelectronics
applications.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 14:05:07 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Calzolari",
"Arrigo",
""
],
[
"Ferretti",
"Andrea",
""
],
[
"Nardelli",
"Marco Buongiorno",
""
]
] |
0705.4396 | Milind Vaman Diwan | V. Barger, M. Bishai, D. Bogert, C. Bromberg, A. Curioni, M.
Dierckxsens, M. Diwan, F. Dufour, D. Finley, B.T. Fleming, J. Gallardo, J.
Heim, P. Huber, C.K. Jung, S. Kahn, E. Kearns, H. Kirk, T. Kirk, K. Lande, C.
Laughton, W.Y. Lee, K. Lesko, C. Lewis, P. Litchfield, A.K. Mann, A.
Marchionni, W. Marciano, D. Marfatia, A.D. Marino, M. Marshak, S. Menary, K.
McDonald, M. Messier, W. Pariseau, Z. Parsa, S. Pordes, R. Potenza,
R.Rameika, N. Saoulidou, N. Simos, R. Van Berg, B. Viren, K. Whisnant, R.
Wilson, W. Winter, C. Yanagisawa, F. Yumiceva, E. D. Zimmerman, R. Zwaska | Report of the US long baseline neutrino experiment study | 109 pages, 56 figures, The report, all associated presentations, and
documents produced during this study can be obtained at
http://nwg.phy.bnl.gov/fnal-bnl | null | null | Fermilab-0801-AD-E, BNL-77973-2007-IR | hep-ph | null | This report provides the results of an extensive and important study of the
potential for a U.S. scientific program that will extend our knowledge of
neutrino oscillations well beyond what can be anticipated from ongoing and
planned experiments worldwide. The program examined here has the potential to
provide the U.S. particle physics community with world leading experimental
capability in this intensely interesting and active field of fundamental
research. Furthermore, this capability could be unique compared to anywhere
else in the world because of the available beam intensity and baseline
distances. The present study was initially commissioned in April 2006 by top
research officers of Brookhaven National Laboratory and Fermi National
Accelerator Laboratory and, as the study evolved, it also provided responses to
questions formulated and addressed to the study group by the Neutrino
Scientific Advisory Committee (NuSAG) of the U.S. DOE and NSF. The participants
in the study, its Charge and history, plus the study results and conclusions
are provided in this report and its appendices. A summary of the conclusions is
provided in the Executive Summary.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 14:48:03 GMT"
}
] | 2007-05-31T00:00:00 | [
[
"Barger",
"V.",
""
],
[
"Bishai",
"M.",
""
],
[
"Bogert",
"D.",
""
],
[
"Bromberg",
"C.",
""
],
[
"Curioni",
"A.",
""
],
[
"Dierckxsens",
"M.",
""
],
[
"Diwan",
"M.",
""
],
[
"Dufour",
"F.",
""
],
[
"Finley",
"D.",
""
],
[
"Fleming",
"B. T.",
""
],
[
"Gallardo",
"J.",
""
],
[
"Heim",
"J.",
""
],
[
"Huber",
"P.",
""
],
[
"Jung",
"C. K.",
""
],
[
"Kahn",
"S.",
""
],
[
"Kearns",
"E.",
""
],
[
"Kirk",
"H.",
""
],
[
"Kirk",
"T.",
""
],
[
"Lande",
"K.",
""
],
[
"Laughton",
"C.",
""
],
[
"Lee",
"W. Y.",
""
],
[
"Lesko",
"K.",
""
],
[
"Lewis",
"C.",
""
],
[
"Litchfield",
"P.",
""
],
[
"Mann",
"A. K.",
""
],
[
"Marchionni",
"A.",
""
],
[
"Marciano",
"W.",
""
],
[
"Marfatia",
"D.",
""
],
[
"Marino",
"A. D.",
""
],
[
"Marshak",
"M.",
""
],
[
"Menary",
"S.",
""
],
[
"McDonald",
"K.",
""
],
[
"Messier",
"M.",
""
],
[
"Pariseau",
"W.",
""
],
[
"Parsa",
"Z.",
""
],
[
"Pordes",
"S.",
""
],
[
"Potenza",
"R.",
""
],
[
"Rameika",
"R.",
""
],
[
"Saoulidou",
"N.",
""
],
[
"Simos",
"N.",
""
],
[
"Van Berg",
"R.",
""
],
[
"Viren",
"B.",
""
],
[
"Whisnant",
"K.",
""
],
[
"Wilson",
"R.",
""
],
[
"Winter",
"W.",
""
],
[
"Yanagisawa",
"C.",
""
],
[
"Yumiceva",
"F.",
""
],
[
"Zimmerman",
"E. D.",
""
],
[
"Zwaska",
"R.",
""
]
] |
0705.4397 | Christos Tsagas | Christos G. Tsagas, Anthony Challinor and Roy Maartens | Relativistic cosmology and large-scale structure | Several minor changes, typos corrected, references added and updated
(Physics Reports in press) | Phys.Rept.465:61-147,2008 | 10.1016/j.physrep.2008.03.003 | null | astro-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | General relativity marked the beginning of modern cosmology and it has since
been at the centre of many of the key developments in this field. In the
present review, we discuss the general-relativistic dynamics and perturbations
of the standard cosmological model, the Friedmann-Lemaitre universe, and how
these can explain and predict the properties of the observable universe. Our
aim is to provide an overview of the progress made in several major research
areas, such as linear and non-linear cosmological perturbations, large-scale
structure formation and the physics of the cosmic microwave background
radiation, in view of current and upcoming observations. We do this by using a
single formalism throughout the review, the 1+3 covariant approach to
cosmology, which allows for a uniform and balanced presentation of technical
information and physical insight.
| [
{
"version": "v1",
"created": "Wed, 30 May 2007 17:01:56 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Mar 2008 16:37:24 GMT"
},
{
"version": "v3",
"created": "Thu, 3 Jul 2008 18:15:55 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Tsagas",
"Christos G.",
""
],
[
"Challinor",
"Anthony",
""
],
[
"Maartens",
"Roy",
""
]
] |
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