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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.3514 | Christian Lorenz | Christian D. Lorenz and Alex Travesset | Charge Inversion of Divalent Ionic Solutions in Silica Channels | 5 pages, 5 figures | Phys. Rev. E 75, 061202 (2007) | 10.1103/PhysRevE.75.061202 | null | cond-mat.mtrl-sci | null | Recent experiments (F.H.J. Van Der Heyden et al., PRL 96, 224502 (2006)) of
streaming currents in silica nanochannels with divalent ions report charge
inversion, i.e. interfacial charges attracting counterions in excess of their
own nominal charge, in conflict with existing theoretical and simulation
results. We reveal the mechanism of charge inversion by using all-atomic
molecular dynamics simulations. Our results show excellent agreement with
experiments, both qualitatively and quantitatively. We further discuss the
implications of our study for the general problem of ionic correlations in
solutions as well as in regards of the properties of silica-water interfaces.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 12:10:37 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Lorenz",
"Christian D.",
""
],
[
"Travesset",
"Alex",
""
]
] |
0706.3515 | Andr\'e Leroy | T.Y.Lam (University of California, Berkeley), A. Leroy (Universit\'e
d'Artois, France), A. Ozturk (University of Mons, Belgium) | Wedderburn polynomials over division rings, II | 31 pages, sequel of the paper entitled "Wedderburn polynomial over
division rings, published in Journal of Pure and Applied Algebra, 186 (2004)
43-76. 26 Cf. also http://users.skynet.be/sky83817/ | null | null | null | math.RA | null | A polynomial $f(t)$ in an Ore extension $K[t;S,D]$ over a division ring $K$
is a Wedderburn polynomial if $f(t)$ is monic and is the minimal polynomial of
an algebraic subset of $K$. These polynomials have been studied in "Wedderburn
polynomials over division rings,I (Journal of Pure and Applied Algebra, Vol.
186, (2004), 43-76). In this paper, we continue this study and give some
applications to triangulation, diagonalization and eigenvalues of matrices over
a division ring in the general setting of $(S,D)$-pseudo-linear
transformations. In the last section we introduce and study the notion of
$G$-algebraic sets which, in particular, permits generalization of Wedderburn's
theorem relative to factorization of central polynomials.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 13:26:17 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Lam",
"T. Y.",
"",
"University of California, Berkeley"
],
[
"Leroy",
"A.",
"",
"Université\n d'Artois, France"
],
[
"Ozturk",
"A.",
"",
"University of Mons, Belgium"
]
] |
0706.3516 | Maxim Titov | Maxim Titov | New Developments and Future Perspectives of Gaseous Detectors | CEA SACLAY, DAPNIA, France and Albert-Ludwigs-University of Freiburg.
Invited Plenary Talk at the 2007 Vienna Instrumentation Conference, February
19-24, 2007 | Nucl.Instrum.Meth.A581:25-37,2007 | 10.1016/j.nima.2007.07.022 | null | physics.ins-det | null | Gaseous detectors are fundamental components of all present and planned high
energy physics experiments.
Over the past decade two representatives (GEM, Micromegas) of the
Micro-Pattern Gas Detector (MPGD) concept have become increasingly important;
the high radiation resistance and excellent spatial and time resolution make
them an invaluable tool to confront future detector challenges at the next
generation of colliders.
Novel structures where GEM and Micromegas are directly coupled to the CMOS
multi-pixel readout represent an exciting field and allow to reconstruct
fine-granularity, two-dimensional images of physics events. Originally
developed for the high energy physics, MPGD applications have expanded to
astrophysics, neutrino physics, neutron detection and medical imaging.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 12:25:53 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Titov",
"Maxim",
""
]
] |
0706.3517 | Shingo Takeuchi | Naoyuki Kawahara (KEK), Jun Nishimura (KEK, SOKENDAI), Shingo Takeuchi
(SOKENDAI) | Phase structure of matrix quantum mechanics at finite temperature | 17 pages, 9 figures, (v2) refined arguments in section 3 ; reference
added | JHEP0710:097,2007 | 10.1088/1126-6708/2007/10/097 | KEK-TH-1160 | hep-th hep-lat | null | We study matrix quantum mechanics at finite temperature by Monte Carlo
simulation. The model is obtained by dimensionally reducing 10d U(N) pure
Yang-Mills theory to 1d. Following Aharony et al., one can view the same model
as describing the high temperature regime of (1+1)d U(N) super Yang-Mills
theory on a circle. In this interpretation an analog of the deconfinement
transition was conjectured to be a continuation of the black-hole/black-string
transition in the dual gravity theory. Our detailed analysis in the critical
regime up to N=32 suggests the existence of the non-uniform phase, in which the
eigenvalue distribution of the holonomy matrix is non-uniform but gapless. The
transition to the gapped phase is of second order. The internal energy is
constant (giving the ground state energy) in the uniform phase, and rises
quadratically in the non-uniform phase, which implies that the transition
between these two phases is of third order.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 14:45:57 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Jul 2007 11:30:46 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kawahara",
"Naoyuki",
"",
"KEK"
],
[
"Nishimura",
"Jun",
"",
"KEK, SOKENDAI"
],
[
"Takeuchi",
"Shingo",
"",
"SOKENDAI"
]
] |
0706.3518 | Toby Wiseman | Simon Catterall and Toby Wiseman | Towards lattice simulation of the gauge theory duals to black holes and
hot strings | 49 pages, 14 figures | JHEP0712:104,2007 | 10.1088/1126-6708/2007/12/104 | null | hep-lat gr-qc hep-th | null | A generalization of the AdS/CFT conjecture postulates a duality between IIA
string theory and 16 supercharge Yang-Mills quantum mechanics in the large N 't
Hooft limit. At low temperatures string theory describes black holes, whose
thermodynamics may hence be studied using the dual quantum mechanics. This
quantum mechanics is strongly coupled which motivates the use of lattice
techniques. We argue that, contrary to expectation, the theory when discretized
naively will nevertheless recover continuum supersymmetry as the lattice
spacing is sent to zero. We test these ideas by studying the 4 supercharge
version of this Yang-Mills quantum mechanics in the 't Hooft limit. We use both
a naive lattice action and a manifestly supersymmetric action. Using Monte
Carlo methods we simulate the Euclidean theories, and study the lattice
continuum limit, for both thermal and non-thermal periodic boundary conditions,
confirming continuum supersymmetry is recovered for the naive action when
appropriate. We obtain results for the thermal system with N up to 12. These
favor the existence of a single deconfined phase for all non-zero temperatures.
These results are an encouraging indication that the 16 supercharge theory is
within reach using similar methods and resources.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 13:21:15 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Catterall",
"Simon",
""
],
[
"Wiseman",
"Toby",
""
]
] |
0706.3519 | Kaori Nagashima | Kaori Nagashima, Hiroaki Isobe, Takaaki Yokoyama, Takako T. Ishii,
Takenori J. Okamoto and Kazunari Shibata | Triggering Mechanism for the Filament Eruption on 2005 September 13 in
Active Region NOAA 10808 | 31 pages, 15 figures, 2 tables, accepted for publication in ApJ | Astrophys.J. 668 (2007) 533-545 | 10.1086/521139 | null | astro-ph | null | On 2005 September 13 a filament eruption accompanied by a halo CME occurred
in the most flare-productive active region NOAA 10808 in Solar Cycle 23. Using
multi-wavelength observations before the filament eruption on Sep. 13th, we
investigate the processes leading to the catastrophic eruption. We find that
the filament slowly ascended at a speed of 0.1km/s over two days before the
eruption. During slow ascending, many small flares were observed close to the
footpoints of the filament, where new magnetic elements were emerging. On the
basis of the observational facts we discuss the triggering mechanism leading to
the filament eruption. We suggest the process toward the eruption as follows:
First, a series of small flares played a role in changing the topology of the
loops overlying the filament. Second, the small flares gradually changed the
equilibrium state of the filament and caused the filament to ascend slowly over
two days. Finally, a C2.9 flare that occurred when the filament was close to
the critical point for loss of equilibrium directly led to the catastrophic
filament eruption right after itself.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 13:40:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Nagashima",
"Kaori",
""
],
[
"Isobe",
"Hiroaki",
""
],
[
"Yokoyama",
"Takaaki",
""
],
[
"Ishii",
"Takako T.",
""
],
[
"Okamoto",
"Takenori J.",
""
],
[
"Shibata",
"Kazunari",
""
]
] |
0706.3520 | Jan Mandel | Deborah H. Glueck, Anis Karimpour-Fard, Jan Mandel, Keith E. Muller | On probabilities for separating sets of order statistics | 10 pages | null | null | null | stat.CO math.PR math.ST stat.TH | null | Consider a set of order statistics that arise from sorting samples from two
different populations, each with their own, possibly different distribution
function. The probability that these order statistics fall in disjoint, ordered
intervals, and that of the smallest statistics, a certain number come from the
first populations, are given in terms of the two distribution functions. The
result is applied to computing the joint probability of the number of
rejections and the number of false rejections for the Benjamini-Hochberg false
discovery rate procedure.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 15:10:12 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Glueck",
"Deborah H.",
""
],
[
"Karimpour-Fard",
"Anis",
""
],
[
"Mandel",
"Jan",
""
],
[
"Muller",
"Keith E.",
""
]
] |
0706.3521 | Michael Sadovsky | Michael G.Sadovsky, Alexander A.Gliskov | Towards the Typology of Elections at Russia | null | null | null | null | physics.soc-ph | null | A distinction in reasons and motives for choosing a particular political
leader establishes the key difference between older and young democracy. The
former is based on electoral history, while the latter is based on feelings and
personal attitude. Besides, a comparatively abundant number of political
figures (persons or parties and associations) is specific for young
democracies. The problem of a reference votes' distribution is analyzed.
Lefevbre's theory of a reflexive control is supposed to make the basis for
indifferent choice of political figures. This theory yields a golden section
split of votes (or the series of Fibonacci numbers, for the case of multiple
choice). A typology of political campaigns based on this theory is proposed. A
proximity of ratings of competing persons means the highest electoral tension,
a leadership of a person means a high level of mobilization; a neutral
situation corresponds to Fibonacci numbers distribution of votes.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 15:31:55 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Sadovsky",
"Michael G.",
""
],
[
"Gliskov",
"Alexander A.",
""
]
] |
0706.3522 | Loic Vanel | Pierre-Philippe Cortet (Phys-ENS), Loic Vanel (Phys-ENS), Sergio
Ciliberto (Phys-ENS) | A dynamical law for slow crack growth in polycarbonate films | null | null | 10.1103/PhysRevLett.99.205502 | null | physics.class-ph | null | We study experimentally the slow growth of a single crack in polycarbonate
films submitted to uniaxial and constant imposed stress. For this visco-plastic
material, we uncover a dynamical law that describes the dependence of the
instantaneous crack velocity with experimental parameters. The law involves a
Dugdale-Barenblatt static description of crack tip plastic zones associated to
an Eyring's law and an empirical dependence with the crack length that may come
from a residual elastic field.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 15:48:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cortet",
"Pierre-Philippe",
"",
"Phys-ENS"
],
[
"Vanel",
"Loic",
"",
"Phys-ENS"
],
[
"Ciliberto",
"Sergio",
"",
"Phys-ENS"
]
] |
0706.3523 | Olivier Finkel | Dominique Lecomte (UMR 7586), Olivier Finkel (LIP) | There Exist some Omega-Powers of Any Borel Rank | To appear in the Proceedings of the 16th EACSL Annual Conference on
Computer Science and Logic, CSL 2007, Lausanne, Switzerland, September 11-15,
2007, Lecture Notes in Computer Science, (c) Springer, 2007 | Dans Proceedings of the 16th EACSL Annual Conference on Computer
Science and Logic, CSL 2007, - 16th EACSL Annual Conference on Computer
Science and Logic, CSL 2007, September 11-15, 2007, Lausanne : Suisse | null | null | cs.LO cs.CC math.LO | null | Omega-powers of finitary languages are languages of infinite words
(omega-languages) in the form V^omega, where V is a finitary language over a
finite alphabet X. They appear very naturally in the characterizaton of regular
or context-free omega-languages. Since the set of infinite words over a finite
alphabet X can be equipped with the usual Cantor topology, the question of the
topological complexity of omega-powers of finitary languages naturally arises
and has been posed by Niwinski (1990), Simonnet (1992) and Staiger (1997). It
has been recently proved that for each integer n > 0, there exist some
omega-powers of context free languages which are Pi^0_n-complete Borel sets,
that there exists a context free language L such that L^omega is analytic but
not Borel, and that there exists a finitary language V such that V^omega is a
Borel set of infinite rank. But it was still unknown which could be the
possible infinite Borel ranks of omega-powers. We fill this gap here, proving
the following very surprising result which shows that omega-powers exhibit a
great topological complexity: for each non-null countable ordinal alpha, there
exist some Sigma^0_alpha-complete omega-powers, and some Pi^0_alpha-complete
omega-powers.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 16:03:36 GMT"
}
] | 2008-03-12T00:00:00 | [
[
"Lecomte",
"Dominique",
"",
"UMR 7586"
],
[
"Finkel",
"Olivier",
"",
"LIP"
]
] |
0706.3524 | Philippe Thebault | Hans Scholl, Francesco Marzari, Philippe Thebault | Relative velocities among accreting planetesimals in binary systems: the
circumbinary case | accepted for publication in MNRAS | null | 10.1111/j.1365-2966.2007.12145.x | null | astro-ph | null | We numerically investigate the possibility of planetesimal accretion in
circumbinary disks, under the coupled influence of both stars' secular
perturbations and friction due to the gaseous component of the protoplanetary
disk. We focus on one crucial parameter: the distribution of encounter
velocities between planetesimals in the 0.5 to 100km size range. An extended
range of binary systems with differing orbital parameters is explored. The
resulting encounter velocities are compared to the threshold velocities below
which the net outcome of a collision is accumulation into a larger body instead
of mass erosion. For each binary configuration, we derive the critical radial
distance from the binary barycenter beyond which planetesimal accretion is
possible. This critical radial distance is smallest for equal-mass binaries on
almost circular orbits. It shifts to larger values for increasing
eccentricities and decreasing mass ratio. The importance of the planetesimals'
orbital alignments of planetesimals due to gas drag effects is discussed.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 16:53:05 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Scholl",
"Hans",
""
],
[
"Marzari",
"Francesco",
""
],
[
"Thebault",
"Philippe",
""
]
] |
0706.3525 | James Lindesay | James Lindesay | Insights into the Evolution of Horizons from Non-Orthogonal Temporal
Coordinates | 40 pages, 14 figures, Invited talk presented at the Herbert W. Jones
Memorial Seminar, 19 April 2007, Florida A&M University | null | null | null | gr-qc | null | The introduction of coordinates representing the points of view of various
observers results in the possibility of horizons when acceleration and
gravitation are included. A horizon is a surface of possible light beams in a
region of space of finite distance from the observer, which means that since
nothing travels faster than light, events on the far side of a horizon cannot
influence those on the causal side. A black hole has such a horizon, where some
radially outgoing light beams can never reach a distant (or even nearby)
observer. However, since one suspects that black holes can swallow energy, and
even evaporate by Hawking radiation, such horizons must take on a time
dependency. A naive introduction of temporal dependency results in infinities
(singularities) in energy densities, suggesting in such descriptions that an
in-falling observer would encounter a hard surface at the horizon. However, if
coordinates representing space-time as analogous to a "flowing river" are used
to describe the dynamics of a black hole, no such singularities are
encountered. Such a parameterization of time dependent horizons will be offered
in this presentation. A Penrose space-time diagram (which represents the entire
space-time on a finite diagram with light beams always moving at a 45 degree
angle to vertical) describing the growth and evaporation of an example black
hole, along with the resulting coordinate anomaly, will be constructed.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 17:08:58 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Lindesay",
"James",
""
]
] |
0706.3526 | Paul Busch | Paul Busch | "No Information Without Disturbance": Quantum Limitations of Measurement | Invited contribution, "Quantum Reality, Relativistic Causality, and
Closing the Epistemic Circle: An International Conference in Honour of Abner
Shimony", Perimeter Institute, Waterloo, Ontario, Canada, July 18-21, 2006,
Editors J. Christian, W.Myrvold, Springer-Verlag, 2008, ISSN: 978-1-4020-9106 | null | 10.1007/978-1-4020-9107-0 | null | quant-ph | null | In this contribution I review rigorous formulations of a variety of
limitations of measurability in quantum mechanics. To this end I begin with a
brief presentation of the conceptual tools of modern measurement theory. I will
make precise the notion that quantum measurements necessarily alter the system
under investigation and elucidate its connection with the complementarity and
uncertainty principles.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 17:09:37 GMT"
}
] | 2011-01-04T00:00:00 | [
[
"Busch",
"Paul",
""
]
] |
0706.3527 | Neil Oxtoby | Neil P. Oxtoby, Jay Gambetta and H.M. Wiseman | Model for monitoring of a charge qubit using a radio-frequency quantum
point contact including experimental imperfections | 12 pages, 2 colour figures. v3 is published version (minor changes
since v2) | Phys. Rev. B 77, 125304 (2008) | 10.1103/PhysRevB.77.125304 | null | cond-mat.mes-hall quant-ph | null | The extension of quantum trajectory theory to incorporate realistic
imperfections in the measurement of solid-state qubits is important for quantum
computation, particularly for the purposes of state preparation and
error-correction as well as for readout of computations. Previously this has
been achieved for low-frequency (dc) weak measurements. In this paper we extend
realistic quantum trajectory theory to include radio frequency (rf) weak
measurements where a low-transparency quantum point contact (QPC), coupled to a
charge qubit, is used to damp a classical oscillator circuit. The resulting
realistic quantum trajectory equation must be solved numerically. We present an
analytical result for the limit of large dissipation within the oscillator
(relative to the QPC), where the oscillator slaves to the qubit. The rf+dc mode
of operation is considered. Here the QPC is biased (dc) as well as subjected to
a small-amplitude sinusoidal carrier signal (rf). The rf+dc QPC is shown to be
a low-efficiency charge-qubit detector, that may nevertheless be higher than
the dc-QPC (which is subject to 1/f noise).
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 17:55:15 GMT"
},
{
"version": "v2",
"created": "Tue, 30 Oct 2007 16:30:35 GMT"
},
{
"version": "v3",
"created": "Thu, 6 Mar 2008 16:00:41 GMT"
}
] | 2008-03-06T00:00:00 | [
[
"Oxtoby",
"Neil P.",
""
],
[
"Gambetta",
"Jay",
""
],
[
"Wiseman",
"H. M.",
""
]
] |
0706.3528 | Louis-Serge Bouchard | Louis-S. Bouchard | RF Shimming Pulses For Ex-Situ NMR Spectroscopy and Imaging Using B1
Inhomogeneities | null | null | null | null | physics.chem-ph | null | I describe a method for generating "shim pulses" for NMR spectroscopy and
imaging (MRI) by taking advantage of the inherent inhomogeneity in the static
and radiofrequency (RF) fields of a one-sided NMR system. The RF inhomogeneity
here is assumed, without loss of generality, to be a linear gradient. General
polynomials in the spatial variables can be generated using x, y and z RF
gradients using trains of hard pulses which result in linear combinations of
monomials xy, y^2, xz etc., and any desired scalings of these monomials. The
basic shim pulse is constructed using small tip angle approximations.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 18:06:54 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Bouchard",
"Louis-S.",
""
]
] |
0706.3529 | Yuli Nazarov | Yuli V. Nazarov | Mesoscopic fluctuations of spin currents | 13 pages, submitted to New J.P | New Journal of Physics 9 (2007) 352 | 10.1088/1367-2630/9/9/352 | null | cond-mat.mes-hall | null | Spin currents may be generated by applying bias voltages V to the
nanostructures even in the absence of spin-active ferromagnetic interfaces.
Most theoretical proposals concentrate on a concrete spin-orbit interaction and
on the disorder-averaged effect. It remains underappreciated that any
spin-orbit interaction produces random spin currents with a typical amplitude
e^2 V/\hbar not affected by disorder. This work addresses such mesoscopic
fluctuations of spin currents for generic model of a nanostructure where
several quantum connectors meet in a single node. The analysis is performed in
the framework of recently developed quantum circuit theory of G_Q corrections
and reveals four distinct mechanisms of spin current fluctuations. The results
are elaborated for simple models of tunnel and ballistic connectors.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 17:31:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Nazarov",
"Yuli V.",
""
]
] |
0706.3530 | Francesco Hautmann | F. Hautmann | Rescattering effects and the determination of the gluon density for x <<
1 | Talk presented at the XLII Rencontres de Moriond (La Thuile, March
2007) | null | null | null | hep-ph | null | We consider the possible role of rescattering effects in the determination of
the gluon density for the LHC from DIS data. We discuss a method that uses
results of s-channel calculations to estimate these effects, and comment on
potential applications to diffractive and multi-parton interactions.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 17:35:14 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Hautmann",
"F.",
""
]
] |
0706.3531 | Edward Shuryak | E.V.Shuryak | On the Origin of the "Ridge" phenomenon induced by Jets in Heavy Ion
Collisions | null | Phys.Rev.C76:047901,2007 | 10.1103/PhysRevC.76.047901 | null | nucl-th | null | We argue that "ridge" in 2-particle correlation function associated with hard
trigger at RHIC heavy ion collisions is naturally explained by an interrelation
of jet quenching and hydrodynamical transverse flow. The excess particles
forming the ridge are produced by QCD bremsstrahlung along the beam (and thus
have wide rapidity distribution) and then boosted by transverse flow.
Nontrivial correlation between directions of the jet and the radial flow is
provided by jet quenching: our straightforward and basically
parameter-independent calculation reproduces the angular shape, width and other
properties of the "ridge".
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 15:44:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Shuryak",
"E. V.",
""
]
] |
0706.3532 | Paul Busch | Paul Busch | On the Sharpness and Bias of Quantum Effects | Substantially expanded version, with new results and some proofs
corrected | Foundations of Physics 39 (2009) 712-730 | 10.1007/s10701-009-9287-8 | null | math-ph math.MP quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The question of quantifying the sharpness (or unsharpness) of a quantum
mechanical effect is investigated. Apart from sharpness, another property,
bias, is found to be relevant for the joint measurability or coexistence of two
effects. Measures of bias will be defined and examples given.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 18:33:18 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Feb 2009 23:12:25 GMT"
}
] | 2010-04-20T00:00:00 | [
[
"Busch",
"Paul",
""
]
] |
0706.3533 | Sunghwan Jung | Sunghwan Jung, Kathleen Mareck, Lisa Fauci, and Michael J. Shelley | Rotational dynamics of a superhelix towed in a Stokes fluid | null | null | 10.1063/1.2800287 | null | physics.flu-dyn physics.bio-ph | null | Motivated by the intriguing motility of spirochetes (helically-shaped
bacteria that screw through viscous fluids due to the action of internal
periplasmic flagella), we examine the fundamental fluid dynamics of
superhelices translating and rotating in a Stokes fluid. A superhelical
structure may be thought of as a helix whose axial centerline is not straight,
but also a helix. We examine the particular case where these two superimposed
helices have different handedness, and employ a combination of experimental,
analytic, and computational methods to determine the rotational velocity of
superhelical bodies being towed through a very viscous fluid. We find that the
direction and rate of the rotation of the body is a result of competition
between the two superimposed helices; for small axial helix amplitude, the body
dynamics is controlled by the short-pitched helix, while there is a cross-over
at larger amplitude to control by the axial helix. We find far better, and
excellent, agreement of our experimental results with numerical computations
based upon the method of Regularized Stokeslets than upon the predictions of
classical resistive force theory.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 18:56:00 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Jung",
"Sunghwan",
""
],
[
"Mareck",
"Kathleen",
""
],
[
"Fauci",
"Lisa",
""
],
[
"Shelley",
"Michael J.",
""
]
] |
0706.3534 | Miguel Ib\'a\~nez Berganza | Miguel Ib\'a\~nez Berganza, Alberto Petri and Pietro Coletti | Dynamic metastability in the two-dimensional Potts ferromagnet | 6 pages, 4 figures. Different method for the estimation of the
metastable endpoints in sec III and minor corrections. Updated bibliography.
Conclusions and Introduction unchanged | null | null | null | cond-mat.stat-mech | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the non-equilibrium dynamics of the 2D Potts model on the
square lattice after a quench below the discontinuous transition point. By
means of numerical simulations of systems with q =12,24 and 48 we observe the
onset of a stationary regime below the temperature-driven transition, in a
temperature interval decreasing with the system size and increasing with q.
These results obtained dynamically agree with those obtained from the
analytical continuation of the free energy (Meunier and Morel, 2000), from
which metastability in the 2D Potts model results to be a finite size effect.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 19:10:27 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Feb 2014 14:50:31 GMT"
}
] | 2014-02-24T00:00:00 | [
[
"Berganza",
"Miguel Ibáñez",
""
],
[
"Petri",
"Alberto",
""
],
[
"Coletti",
"Pietro",
""
]
] |
0706.3535 | Nandor Sieben | Nandor Sieben | Avoidable Sets in The Bicyclic Inverse Semigroup | null | Ars. Combin 77(2005), 273--288 | null | null | math.CO math.GR | null | A subset $U$ of a set $S$ with a binary operation is called {\it avoidable}
if $S$ can be partitioned into two subsets $A$ and $B$ such that no element of
$U$ can be written as a product of two distinct elements of $A$ or as the
product of two distinct elements of $B$. The avoidable sets of the bicyclic
inverse semigroup are classified.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 20:35:40 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Sieben",
"Nandor",
""
]
] |
0706.3536 | Michael Wilkinson | M. Wilkinson, B. Mehlig and V. Uski | Stokes trapping and planet formation | 30 pages, 4 figures. Revised version has improved concluding remarks,
extended discussion of sticking velocity | Astrophys. J. Suppl. Ser. 176, 484 (2008) | 10.1086/533533 | null | astro-ph | null | It is believed that planets are formed by aggregation of dust particles
suspended in the turbulent gas forming accretion disks around developing stars.
We describe a mechanism, termed 'Stokes trapping', by which turbulence limits
the growth of aggregates of dust particles, so that their Stokes number
(defined as the ratio of the damping time of the particles to the Kolmogorov
dissipation timescale) remains close to unity. We discuss possible mechanisms
for avoiding this barrier to further growth. None of these is found to be
satisfactory and we introduce a new theory which does not involve the growth of
small clusters of dust grains.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 21:56:35 GMT"
},
{
"version": "v2",
"created": "Sat, 29 Sep 2007 09:40:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wilkinson",
"M.",
""
],
[
"Mehlig",
"B.",
""
],
[
"Uski",
"V.",
""
]
] |
0706.3537 | Lesfari Ahmed | A. Lesfari | The Yang Mills system and cyclic covering of abelian varieties | 13 pages, to be published in International Journal of Pure and
Applied Mathematical Sciences | null | null | null | math-ph math.DS math.MP | null | In this paper, we consider a dynamical system related to the Yang-Mills
system for a field with gauge group SU(2). We solve this system in terms of
genus two hyperelliptic functions and we show that it is algebraic completely
integrable in the generalized sense.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 22:31:04 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Lesfari",
"A.",
""
]
] |
0706.3538 | Fabrizio Canfora | F. Canfora | Some solutions with torsion in Chern-Simons gravity and observable
effects | 17 pages, no figures; test polished; references added; physical
interpretation clarified; | null | null | null | gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is shown that in all odd dimensional Chern-Simons theories states in which
the torsion is non zero (but it can approach smoothly to zero outside suitable
regions) do exist. Some possible observational effects related to neutrino
oscillations are pointed out. In the theory of continuum media (in which
suitable defects can be described by localized non vanishing torsion) "the
gravitational intuition" is a rather useful tool to describe the physical
effects of such defects. A possible astrophysical application is shortly
described.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 22:31:19 GMT"
},
{
"version": "v2",
"created": "Wed, 2 Jul 2008 15:41:53 GMT"
}
] | 2008-07-02T00:00:00 | [
[
"Canfora",
"F.",
""
]
] |
0706.3539 | Mark C. Wilson | Primo\v{z} Poto\v{c}nik, Jozef \v{S}ir\'a\v{n}, Jana \v{S}iagiov\'a,
Manuel E. Lladser, Mark C. Wilson | The diameter of random Cayley digraphs of given degree | 11 pages | null | null | null | math.CO | null | We consider random Cayley digraphs of order $n$ with uniformly distributed
generating set of size $k$. Specifically, we are interested in the asymptotics
of the probability such a Cayley digraph has diameter two as $n\to\infty$ and
$k=f(n)$. We find a sharp phase transition from 0 to 1 at around $k = \sqrt{n
\log n}$. In particular, if $f(n)$ is asymptotically linear in $n$, the
probability converges exponentially fast to 1.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 23:07:54 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Potočnik",
"Primož",
""
],
[
"Širáň",
"Jozef",
""
],
[
"Šiagiová",
"Jana",
""
],
[
"Lladser",
"Manuel E.",
""
],
[
"Wilson",
"Mark C.",
""
]
] |
0706.3540 | Louis-Serge Bouchard | Louis-S. Bouchard | Finite Element Formulation of the Bloch Equations with Dipolar Field
Effects | null | null | null | null | physics.chem-ph | null | A Galerkin finite element (FEM) formulation for the Bloch equations with
dipolar field is presented which makes possible the derivation of weak
solutions to the Bloch equations. The FEM formulation has the advantage that
the equations of motion are local in real space, eliminating the global
truncation errors associated with calculations of the dipolar field in Fourier
space. The dipolar field and other geometric parameters are calculated only
once, before the simulation, and used as an initial condition rather than
re-calculated at every time step of some numerical integration.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 23:32:45 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Bouchard",
"Louis-S.",
""
]
] |
0706.3541 | Nick P. Proukakis | N.P. Proukakis | Beyond Gross-Pitaevskii Mean Field Theory | Review Article (19 Pages) - To appear in 'Emergent Nonlinear
Phenomena in Bose-Einstein Condensates: Theory and Experiment', Edited by
P.G. Kevrekidis, D.J. Frantzeskakis and R. Carretero-Gonzalez (Springer
Verlag) | null | 10.1007/978-3-540-73591-5_18 | null | cond-mat.other | null | A large number of effects related to the phenomenon of Bose-Einstein
Condensation (BEC) can be understood in terms of lowest order mean field
theory, whereby the entire system is assumed to be condensed, with thermal and
quantum fluctuations completely ignored. Such a treatment leads to the
Gross-Pitaevskii Equation (GPE) used extensively throughout this book. Although
this theory works remarkably well for a broad range of experimental parameters,
a more complete treatment is required for understanding various experiments,
including experiments with solitons and vortices. Such treatments should
include the dynamical coupling of the condensate to the thermal cloud, the
effect of dimensionality, the role of quantum fluctuations, and should also
describe the critical regime, including the process of condensate formation.
The aim of this Chapter is to give a brief but insightful overview of various
recent theories, which extend beyond the GPE. To keep the discussion brief,
only the main notions and conclusions will be presented. This Chapter
generalizes the presentation of Chapter 1, by explicitly maintaining
fluctuations around the condensate order parameter. While the theoretical
arguments outlined here are generic, the emphasis is on approaches suitable for
describing single weakly-interacting atomic Bose gases in harmonic traps.
Interesting effects arising when condensates are trapped in double-well
potentials and optical lattices, as well as the cases of spinor condensates,
and atomic-molecular coupling, along with the modified or alternative theories
needed to describe them, will not be covered here.
| [
{
"version": "v1",
"created": "Sun, 24 Jun 2007 23:36:46 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Proukakis",
"N. P.",
""
]
] |
0706.3542 | Yasuhiro Asano | Yasuhiro Asano, Yuki Sawa, Yukio Tanaka, Alexander A. Golubov | Odd-frequency Pairs and Josephson Current through a Strong Ferromagnet | 12 pages 14 figures embedded | Physical Review B 76, 224525 (2007) | 10.1103/PhysRevB.76.224525 | null | cond-mat.supr-con | null | We study Josephson current in superconductor / diffusive ferromagnet
/superconductor junctions by using the recursive Green function method. When
the exchange potential in a ferromagnet is sufficiently large as compared to
the pair potential in a superconductor, an ensemble average of Josephson
current is much smaller than its mesoscopic fluctuations. The Josephson current
vanishes when the exchange potential is extremely large so that a ferromagnet
is half-metallic. Spin-flip scattering at junction interfaces drastically
changes the characteristic behavior of Josephson current. In addition to
spin-singlet Cooper pairs, equal-spin triplet pairs penetrate into a half
metal. Such equal-spin pairs have an unusual symmetry property called
odd-frequency symmetry and carry the Josephson current through a half metal.
The penetration of odd-frequency pairs into a half metal enhances the low
energy quasiparticle density of states, which could be detected experimentally
by scanning tunneling spectroscopy. We will also show that odd-frequency pairs
in a half metal cause a nonmonotonic temperature dependence of the critical
Josephson current.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 00:33:48 GMT"
},
{
"version": "v2",
"created": "Mon, 3 Dec 2007 00:32:11 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Asano",
"Yasuhiro",
""
],
[
"Sawa",
"Yuki",
""
],
[
"Tanaka",
"Yukio",
""
],
[
"Golubov",
"Alexander A.",
""
]
] |
0706.3543 | Xianhui Zhong | Xian-Hui Zhong, Qiang Zhao, Jun He and Bijan Saghai | Study of \pi^{-}p \to \eta n at low energies in a chiral constituent
quark model | 17 pages, 5 figures. Version accepted by PRC. Some changes in the
t-channel due to an error in the code | Phys.Rev.C76:065205,2007 | 10.1103/PhysRevC.76.065205 | null | nucl-th | null | A chiral quark model approach is extended to the study of the $\pi N$
scattering at low energies. The process of $\pi^{-}p \to \eta n$ near threshold
is investigated. The model is successful in describing the differential cross
sections and total cross section near the $\eta$ production threshold. The
roles of the resonances in $n\leq 2$ shells are clarified. Near threshold, the
$S_{11}(1535)$ dominates the reactions, while the interferences from the
$S_{11}(1650)$ turn out to be destructive around $W\lesssim 1.6$ GeV. The
$D_{13}(1520)$ is crucial to give correct shapes of the differential cross
sections. The nucleon pole term contributions are significant. The
$P_{11}(1710)$ plays an important role around the c.m. energy $W=1.7$ GeV, it
is crucial to produce an enhancement in the region of $W>1.6$ GeV as suggested
by the data for total cross section. The $t$-channel is negligible in the
reactions.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 01:02:53 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Jun 2007 02:12:59 GMT"
},
{
"version": "v3",
"created": "Sun, 18 Nov 2007 11:51:01 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Zhong",
"Xian-Hui",
""
],
[
"Zhao",
"Qiang",
""
],
[
"He",
"Jun",
""
],
[
"Saghai",
"Bijan",
""
]
] |
0706.3544 | Erik Muller | E. Muller, K. Bekki | The Origin of Large-scale HI structures in the Magellanic Bridge | 5 Pages, 4 Figures, Accepted - MNRAS lett | null | 10.1111/j.1745-3933.2007.00356.x | null | astro-ph | null | We investigate the formation of a number of key large-scale HI features in
the ISM of the Magellanic Bridge using dissipationless numerical simulation
techniques. This study comprises the first direct comparison between detailed
HI maps of the Bridge and numerical simulations. We confirm that the SMC forms
two tidal filaments: a near arm, which forms the connection between the SMC and
LMC, and a counterarm. We show that the HI of the most dense part of the Bridge
can become arranged into a bimodal configuration, and that the formation of a
"loop" of HI, located off the North-Eastern edge of the SMC can be reproduced
simply as a projection of the counter-arm, and without invoking localised
energy-deposition processes such as SNe or stellar winds.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 05:06:24 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 01:15:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Muller",
"E.",
""
],
[
"Bekki",
"K.",
""
]
] |
0706.3545 | Mathias Schulze | Mathias Schulze, Uli Walther | Cohen-Macaulayness and computation of Newton graded toric rings | 20 pages, 4 figures | J. Pure Appl. Alg. 213,8 (2009), 1522-1535. | 10.1016/j.jpaa.2008.11.035 | null | math.AC math.CO | null | Let $H$ be a positive semigroup in $\mathbb{Z}^d$ generated by $A$, and let
$K[H]$ be the associated semigroup ring over a field $K$. We investigate
heredity of the Cohen-Macaulay property from $K[H]$ to both its $A$-Newton
graded ring and to its face rings. We show by example that neither one inherits
in general the Cohen-Macaulay property. On the positive side we show that for
every $H$ there exist generating sets $A$ for which the Newton graduation
preserves Cohen-Macaulayness. This gives an elementary proof for an important
vanishing result on $A$-hypergeometric Euler-Koszul homology. As a tool for our
investigations we develop an algorithm to compute algorithmically the Newton
filtration on a toric ring.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 01:26:46 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Schulze",
"Mathias",
""
],
[
"Walther",
"Uli",
""
]
] |
0706.3546 | Samer Al Kiswany | Samer Al Kiswany, Matei Ripeanu, Sudharshan S. Vazhkudai, Abdullah
Gharaibeh | stdchk: A Checkpoint Storage System for Desktop Grid Computing | 13 pages, 8 figures | null | null | null | cs.DC | null | Checkpointing is an indispensable technique to provide fault tolerance for
long-running high-throughput applications like those running on desktop grids.
This paper argues that a dedicated checkpoint storage system, optimized to
operate in these environments, can offer multiple benefits: reduce the load on
a traditional file system, offer high-performance through specialization, and,
finally, optimize data management by taking into account checkpoint application
semantics. Such a storage system can present a unifying abstraction to
checkpoint operations, while hiding the fact that there are no dedicated
resources to store the checkpoint data. We prototype stdchk, a checkpoint
storage system that uses scavenged disk space from participating desktops to
build a low-cost storage system, offering a traditional file system interface
for easy integration with applications. This paper presents the stdchk
architecture, key performance optimizations, support for incremental
checkpointing, and increased data availability. Our evaluation confirms that
the stdchk approach is viable in a desktop grid setting and offers a low cost
storage system with desirable performance characteristics: high write
throughput and reduced storage space and network effort to save checkpoint
images.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 01:24:46 GMT"
},
{
"version": "v2",
"created": "Fri, 23 Nov 2007 20:51:06 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Kiswany",
"Samer Al",
""
],
[
"Ripeanu",
"Matei",
""
],
[
"Vazhkudai",
"Sudharshan S.",
""
],
[
"Gharaibeh",
"Abdullah",
""
]
] |
0706.3547 | Aidan Sims | Cynthia Farthing, David Pask and Aidan Sims | Crossed products of k-graph C*-algebras by Z^l | 27 pages. Pictures drawn using pgf | null | null | null | math.OA | null | An action of Z^l by automorphisms of a k-graph induces an action of Z^l by
automorphisms of the corresponding k-graph C*-algebra. We show how to construct
a (k+l)-graph whose C*-algebra coincides with the crossed product of the
original k-graph algebra by Z^l. We then investigate the structure of the
crossed-product C*-algebra.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 02:03:09 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Farthing",
"Cynthia",
""
],
[
"Pask",
"David",
""
],
[
"Sims",
"Aidan",
""
]
] |
0706.3548 | Simon O'Toole | S. J. O'Toole, C. G. Tinney, H. R. A. Jones | The Impact of Stellar Oscillations on Doppler Velocity Planet Searches | 5 pages, to appear in MNRAS | null | 10.1111/j.1365-2966.2008.13061.x | null | astro-ph | null | We present a quantitative investigation of the effect of stellar oscillations
on Doppler velocity planet searches. Using data from four asteroseismological
observation campaigns, we find a power law relationship between the noise
impact of these oscillations on Doppler velocities and both the
luminosity-to-mass of the target stars, and observed integration times.
Including the impact of oscillation jitter should improve the quality of
Keplerian fits to Doppler velocity data. The scale of the effect these
oscillations have on Doppler velocity measurements is smaller than that
produced by stellar activity, but is most significant for giant and subgiant
stars, and at short integration times (i.e. less than a few minutes). Such
short observation times tend to be used only for very bright stars. However,
since it is these very same stars that tend to be targeted for the highest
precision observations, as planet searches probe to lower and lower planet
masses, oscillation noise for these stars can be significant and needs to be
accounted for in observing strategies.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 02:05:34 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Feb 2008 01:21:31 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"O'Toole",
"S. J.",
""
],
[
"Tinney",
"C. G.",
""
],
[
"Jones",
"H. R. A.",
""
]
] |
0706.3549 | Shinji Ejiri | Shinji Ejiri | On the existence of the critical point in finite density lattice QCD | 17 pages, 9 figures | Phys.Rev.D77:014508,2008 | 10.1103/PhysRevD.77.014508 | BNL-NT-07/29 | hep-lat hep-ph | null | We propose a method to probe the nature of phase transitions in lattice QCD
at finite temperature and density, which is based on the investigation of an
effective potential as a function of the average plaquette. We analyze data
obtained in a simulation of two-flavor QCD using p4-improved staggered quarks
with bare quark mass $m/T = 0.4$, and find that a first order phase transition
line appears in the high density regime for $\mu_q/T \simge 2.5$. We also
discuss the difference between the phase structures of QCD with non-zero quark
chemical potential and non-zero isospin chemical potential.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 02:12:02 GMT"
},
{
"version": "v2",
"created": "Tue, 11 Dec 2007 00:07:07 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ejiri",
"Shinji",
""
]
] |
0706.3550 | Xiaobo Liu | Xiaobo Liu and Chuu-Lian Terng | The mean curvature flow for isoparametric submanifolds | 24 pages, PDF file | Duke Math. Journal, 147 (2009), no. 1, 157--179 | 10.1215/00127094-2009-009 | null | math.DG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A submanifold in space forms is isoparametric if the normal bundle is flat
and principal curvatures along any parallel normal fields are constant. We
study the mean curvature flow with initial data an isoparametric submanifold in
Euclidean space and sphere. We show that the mean curvature flow preserves the
isoparametric condition, develops singularities in finite time, and converges
in finite time to a smooth submanifold of lower dimension. We also give a
precise description of the collapsing.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 02:15:14 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Nov 2019 05:43:13 GMT"
}
] | 2019-12-02T00:00:00 | [
[
"Liu",
"Xiaobo",
""
],
[
"Terng",
"Chuu-Lian",
""
]
] |
0706.3551 | Prasanta Das Kumar | V. H. Satheesh Kumar, P. K. Suresh and P. K. Das | Supernovae as Probes of Extra Dimensions | 5 pages, no figures, new references are added | AIP Conf.Proc.939:258-262,2007 | 10.1063/1.2803812 | null | hep-ph | null | Since the dawn of the new millennium, there has been a revived interest in
the concept of extra dimensions.In this scenario all the standard model matter
and gauge fields are confined to the 4 dimensions and only gravity can escape
to higher dimensions of the universe.This idea can be tested using table-top
experiments, collider experiments, astrophysical or cosmological observations.
The main astrophysical constraints come from the cooling rate of supernovae,
neutron stars, red giants and the sun. In this article, we consider the energy
loss mechanism of SN1987A and study the constraints it places on the number and
size of extra dimensions and the higher dimensional Planck scale.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 15:50:12 GMT"
},
{
"version": "v2",
"created": "Sat, 7 Jul 2007 03:53:55 GMT"
}
] | 2011-04-11T00:00:00 | [
[
"Kumar",
"V. H. Satheesh",
""
],
[
"Suresh",
"P. K.",
""
],
[
"Das",
"P. K.",
""
]
] |
0706.3552 | Alexander Shashkin | A. A. Shashkin, A. A. Kapustin, E. V. Deviatov, V. T. Dolgopolov, Z.
D. Kvon | Strongly enhanced effective mass in dilute two-dimensional electron
systems: System-independent origin | As published | Phys. Rev. B 76, 241302(R) (2007) | 10.1103/PhysRevB.76.241302 | null | cond-mat.str-el | null | We measure the effective mass in a dilute two-dimensional electron system in
(111)-silicon by analyzing temperature dependence of the Shubnikov-de Haas
oscillations in the low-temperature limit. A strong enhancement of the
effective mass with decreasing electron density is observed. The mass
renormalization as a function of the interaction parameter r_s is in good
agreement with that reported for (100)-silicon, which shows that the relative
mass enhancement is system- and disorder-independent being determined by
electron-electron interactions only.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 15:30:57 GMT"
},
{
"version": "v2",
"created": "Wed, 21 Nov 2007 15:56:43 GMT"
}
] | 2007-12-11T00:00:00 | [
[
"Shashkin",
"A. A.",
""
],
[
"Kapustin",
"A. A.",
""
],
[
"Deviatov",
"E. V.",
""
],
[
"Dolgopolov",
"V. T.",
""
],
[
"Kvon",
"Z. D.",
""
]
] |
0706.3553 | Ralf Metzler | Ralf Metzler, Aleksei V. Chechkin, Joseph Klafter | L\'evy Statistics and Anomalous Transport: L\'evy flights and
Subdiffusion | 36 pages, 15 figures, REVTeX, Review article | null | null | null | cond-mat.stat-mech | null | Levy flights and subdiffusive processes and their properties are discussed.
We derive the space- and time-fractional transport equations, and consider
their solutions in external potentials. An extensive list of references is
included.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 15:22:28 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Metzler",
"Ralf",
""
],
[
"Chechkin",
"Aleksei V.",
""
],
[
"Klafter",
"Joseph",
""
]
] |
0706.3554 | Anatoly Klypin | A. Klypin and F. Prada | Testing gravity with motion of satellites around galaxies: Newtonian
gravity against Modified Newtonian Dynamics | 14 pages, 7 figures. Accepted for publication in ApJ | Astrophys.J.690:1488-1496,2009 | 10.1088/0004-637X/690/2/1488 | null | astro-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The motion of satellite galaxies around normal galaxies at distances 50-500
kpc provides a sensitive test for the theories. We study the surface density
and the velocities of satellites around isolated galaxies in the Sloan Digital
Sky Survey. We find that the surface number-density of satellites declines with
the projected distance as a power law with the slope -1.5-2. The rms velocities
gradually decline: observations exclude constant velocities at a 10 sigma
level. We show that observational data strongly favor the standard model: all
three major statistics of satellites - the number-density profile, the
line-of-sight velocity dispersion, and the distribution function of the
velocities -- agree remarkably well with the predictions of the standard
cosmological model. Thus, that the success of the standard model extends to
scales (50-500) kpc, much lower than what was previously considered. MOND fails
on these scales for models which assume any single power-law number-density
profile of satellites and any constant velocity anisotropy by predicting nearly
constant rms velocities of satellites. Satellite data can be fit by fine-tuned
models, which require (1) specific non-power-law density profile, (2) very
radial orbits at large distances (velocity anisotropy beta =0.6-0.7 at 200-300
kpc), and (3) 2-2.5 times more stellar mass than what is found in the galaxies.
The external gravity force - a necessary component for MOND -- makes the
situation even worse. We argue that a combination of satellite data and
observational constraints on stellar masses make these models very problematic.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 03:15:56 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Sep 2007 01:41:01 GMT"
},
{
"version": "v3",
"created": "Mon, 1 Sep 2008 18:11:39 GMT"
}
] | 2009-01-16T00:00:00 | [
[
"Klypin",
"A.",
""
],
[
"Prada",
"F.",
""
]
] |
0706.3555 | Nobukazu Shimeno | Nobukazu shimeno | A formula for the hypergeometric function of type $BC_n$ | null | null | null | null | math.RT math.QA | null | Formulae of Berezin and Karpelevic for the radial parts of invariant
differential operators and the spherical function on a complex Grassmann
manifold are generalized to the hypergeometric functions associated with root
system of type $BC_n$ under condition that the multiplicity of the middle roots
is zero or one.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 03:02:53 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"shimeno",
"Nobukazu",
""
]
] |
0706.3556 | Kai-Yu Yang | Wei-Qiang Chen, Kai-Yu Yang, T. M. Rice, F. C. Zhang | Quantum Oscillations in Magnetic Field Induced Antiferromagnetic Phase
of Underdoped Cuprates : Application to Ortho-II YBa2Cu3O6.5 | 5 pages, 3 figures | EuroPhys Lett 82 (2008) 17004 | null | null | cond-mat.supr-con | null | Magnetic field induced antiferromagnetic phase of the underdoped cuprates is
studied within the t-t'-J model. A magnetic field suppresses the pairing
amplitude, which in turn may induce antiferromagnetism. We apply our theory to
interpret the recently reported quantum oscillations in high magnetic field in
ortho-II YBa2Cu3O6.5 and propose that the total hole density abstracted from
the oscillation period is reduced by 50% due to the antiferromagnetism.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 03:29:10 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 10:00:07 GMT"
},
{
"version": "v3",
"created": "Thu, 13 Mar 2008 19:11:47 GMT"
}
] | 2008-03-13T00:00:00 | [
[
"Chen",
"Wei-Qiang",
""
],
[
"Yang",
"Kai-Yu",
""
],
[
"Rice",
"T. M.",
""
],
[
"Zhang",
"F. C.",
""
]
] |
0706.3557 | Munekazu Ohno | Munekazu Ohno, Kanji Yoh | Datta-Das type spin-field effect transistor in non-ballistic regime | 8 pages, 3 figures | null | 10.1103/PhysRevB.77.045323 | null | cond-mat.other | null | It is revealed that in spin helix state of (001) quantum well system, strong
suppression of D'yakonov-Perel' spin relaxation process occurs by an interplay
between Rashba and Dresselhaus couplings over a wide range of Rashba coupling
strength. Contrary to common belief in early works, this leads to the finding
that Datta-Das type spin-field effect transistor is actually applicable to more
realistic non-ballistic transport regime in two dimensional electron gas
system.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 04:12:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ohno",
"Munekazu",
""
],
[
"Yoh",
"Kanji",
""
]
] |
0706.3558 | Soumik Pal | Sourav Chatterjee and Soumik Pal | A phase transition behavior for Brownian motions interacting through
their ranks | 30 pages, 1 figures, to appear in PTRF | null | null | null | math.PR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Consider a time-varying collection of n points on the positive real axis,
modeled as exponentials of n Brownian motions whose drift vector at every time
point is determined by the relative ranks of the coordinate processes at that
time. If at each time point we divide the points by their sum, under suitable
assumptions the rescaled point process converges to a stationary distribution
(depending on n and the vector of drifts) as time goes to infinity. This
stationary distribution can be exactly computed using a recent result of Pal
and Pitman. The model and the rescaled point process are both central objects
of study in models of equity markets introduced by Banner, Fernholz, and
Karatzas. In this paper, we look at the behavior of this point process under
the stationary measure as $n$ tends to infinity. Under a certain `continuity at
the edge' condition on the drifts, we show that one of the following must
happen: either (i) all points converge to zero, or (ii) the maximum goes to one
and the rest go to zero, or (iii) the processes converge in law to a
non-trivial Poisson-Dirichlet distribution. The proof employs, among other
things, techniques from Talagrand's analysis of the low temperature phase of
Derrida's Random Energy Model of spin glasses. The main result establishes a
universality property for the BFK models and aids in explicit asymptotic
computations using known results about the Poisson-Dirichlet law.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 04:51:54 GMT"
},
{
"version": "v2",
"created": "Mon, 5 Oct 2009 23:57:11 GMT"
}
] | 2009-10-06T00:00:00 | [
[
"Chatterjee",
"Sourav",
""
],
[
"Pal",
"Soumik",
""
]
] |
0706.3559 | Makoto Yoshida | M. Yoshida, N. Ogata, M. Takigawa, J. Yamaura, M. Ichihara, T. Kitano,
H. Kageyama, Y. Ajiro, K. Yoshimura | Magnetic and Structural Studies of the Quasi-Two-Dimensional Spin-Gap
System (CuCl)LaNb2O7 | 9 pages, 16 figures | J. Phys. Soc. Jpn. 76, 104703 (2007) | 10.1143/JPSJ.76.104703 | null | cond-mat.str-el | null | We report magnetization, nuclear magnetic resonance (NMR), nuclear quadrupole
resonance (NQR), and transmission electron microscopy (TEM) studies on the
quasi-two-dimensional spin-gap system (CuCl)LaNb2O7, a possible candidate for
the J1-J2 model on a square lattice. A sharp single NQR line is observed at the
Cu and Cl sites, indicating that both Cu and Cl atoms occupy a unique site.
However, the electric field gradient tensors at the Cu, Cl, and La sites do not
have axial symmetry. This is incompatible with the reported crystal structure.
Thus the J1-J2 model has to be modified. We propose alternative two-dimensional
dimer models based on the NMR, NQR, and TEM results. The value of the hyperfine
coupling constant at the Cu sites indicates that the spin density is mainly on
the d(3z2-r2) orbital (z parallel c). At 1.5 K, Cu- and Nb-NMR signals
disappear above the critical field Bc1 = 10.3 T determined from the onset of
the magnetization, indicating a field-induced magnetic phase transition at Bc1.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 07:38:23 GMT"
},
{
"version": "v2",
"created": "Fri, 28 Sep 2007 01:10:35 GMT"
}
] | 2017-12-01T00:00:00 | [
[
"Yoshida",
"M.",
""
],
[
"Ogata",
"N.",
""
],
[
"Takigawa",
"M.",
""
],
[
"Yamaura",
"J.",
""
],
[
"Ichihara",
"M.",
""
],
[
"Kitano",
"T.",
""
],
[
"Kageyama",
"H.",
""
],
[
"Ajiro",
"Y.",
""
],
[
"Yoshimura",
"K.",
""
]
] |
0706.3560 | Hvedri Inassaridze | Martin Raussen and Ulrich Fahrenberg | Reparametrizations of Continuous Paths | null | null | null | null | math.GN | null | A reparametrization (of a continuous path) is given by a surjective weakly
increasing self-map of the unit interval. We show that the monoid of
reparametrizations (with respect to compositions) can be understood via
``stop-maps'' that allow to investigate compositions and factorizations, and we
compare it to the distributive lattice of countable subsets of the unit
interval. The results obtained are used to analyse the space of traces in a
topological space, i.e., the space of continuous paths up to reparametrization
equivalence. This space is shown to be homeomorphic to the space of regular
paths (without stops) up to increasing reparametrizations. Directed versions of
the results are important in directed homotopy theory.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 05:55:54 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Raussen",
"Martin",
""
],
[
"Fahrenberg",
"Ulrich",
""
]
] |
0706.3561 | Daniel Fernandez-Fraile | D. Fernandez-Fraile, A. Gomez Nicola | Transport properties of a meson gas | 4 pages, 4 figures, IJMPE style. Contribution to the International
Workshop X Hadron Physics (2007), Florianopolis, Brazil. Accepted for
publication in IJMPE; 1 typo corrected | Int.J.Mod.Phys.E16:3010-3013,2007 | 10.1142/S0218301307008938 | null | hep-ph | null | We present recent results on a systematic method to calculate transport
coefficients for a meson gas (in particular, we analyze a pion gas) at low
temperatures in the context of Chiral Perturbation Theory. Our method is based
on the study of Feynman diagrams with a power counting which takes into account
collisions in the plasma by means of a non-zero particle width. In this way, we
obtain results compatible with analysis of Kinetic Theory with just the leading
order diagram. We show the behavior with temperature of electrical and thermal
conductivities and shear and bulk viscosities, and we discuss the fundamental
role played by unitarity. We obtain that bulk viscosity is negligible against
shear viscosity near the chiral phase transition. Relations between the
different transport coefficients and bounds on them based on different
theoretical approximations are also discussed. We also comment on some
applications to heavy-ion collisions.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 15:52:13 GMT"
},
{
"version": "v2",
"created": "Mon, 9 Jul 2007 14:53:11 GMT"
}
] | 2009-04-16T00:00:00 | [
[
"Fernandez-Fraile",
"D.",
""
],
[
"Nicola",
"A. Gomez",
""
]
] |
0706.3562 | Loic Vanel | St\'ephane Santucci (Phys-ENS), Pierre-Philippe Cortet (Phys-ENS),
St\'ephanie Deschanel (MATEIS), Loic Vanel (Phys-ENS), Sergio Ciliberto
(Phys-ENS) | Subcritical crack growth in fibrous materials | null | Europhysics Letters (EPL) 4, 74 (15/05/2006) 595 | 10.1209/epl/i2005-10575-2 | null | cond-mat.mtrl-sci physics.class-ph | null | We present experiments on the slow growth of a single crack in a fax paper
sheet submitted to a constant force $F$. We find that statistically averaged
crack growth curves can be described by only two parameters : the mean rupture
time $\tau$ and a characteristic growth length $\zeta$. We propose a model
based on a thermally activated rupture process that takes into account the
microstructure of cellulose fibers. The model is able to reproduce the shape of
the growth curve, the dependence of $\zeta$ on $F$ as well as the effect of
temperature on the rupture time $\tau$. We find that the length scale at which
rupture occurs in this model is consistently close to the diameter of cellulose
microfibrils.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 06:38:05 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Santucci",
"Stéphane",
"",
"Phys-ENS"
],
[
"Cortet",
"Pierre-Philippe",
"",
"Phys-ENS"
],
[
"Deschanel",
"Stéphanie",
"",
"MATEIS"
],
[
"Vanel",
"Loic",
"",
"Phys-ENS"
],
[
"Ciliberto",
"Sergio",
"",
"Phys-ENS"
]
] |
0706.3563 | Hyeonjoon Shin | Wontae Kim, Hyeonjoon Shin | Anomaly Analysis of Hawking Radiation from Acoustic Black Hole | 11 pages; added reference, version to appear in JHEP | JHEP0707:070,2007 | 10.1088/1126-6708/2007/07/070 | CQUeST-2007-0093 | hep-th | null | The Hawking radiation from the three dimensional rotating acoustic black hole
is considered from the viewpoint of anomaly cancellation method initiated by
Robinson and Wilczek. Quantum field near the horizon is effectively described
by two dimensional charged field with a charge identified as the angular
momentum m. The fluxes of charge and energy are obtained from the anomaly
cancellation condition and regularity at the horizon, and are shown to match
with those of the two dimensional black body radiation at the Hawking
temperature.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 06:41:39 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Jul 2007 11:03:32 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kim",
"Wontae",
""
],
[
"Shin",
"Hyeonjoon",
""
]
] |
0706.3564 | Loic Vanel | Pierre-Philippe Cortet (Phys-ENS), Matteo Ciccotti (LCVN), Loic Vanel
(Phys-ENS) | Imaging the stick-slip peeling of an adhesive tape under a constant load | null | Journal of Statistical Mechanics: Theory and Experiment 03, March
2007 (05/03/2007) P03005 | 10.1088/1742-5468/2007/03/P03005 | null | cond-mat.mtrl-sci physics.class-ph | null | Using a high speed camera, we study the peeling dynamics of an adhesive tape
under a constant load with a special focus on the so-called stick-slip regime
of the peeling. It is the first time that the very fast motion of the peeling
point is imaged. The speed of the camera, up to 16000 fps, allows us to observe
and quantify the details of the peeling point motion during the stick and slip
phases: stick and slip velocities, durations and amplitudes. First, in contrast
with previous observations, the stick-slip regime appears to be only transient
in the force controlled peeling. Additionally, we discover that the stick and
slip phases have similar durations and that at high mean peeling velocity, the
slip phase actually lasts longer than the stick phase. Depending on the mean
peeling velocity, we also observe that the velocity change between stick and
slip phase ranges from a rather sudden to a smooth transition. These new
observations can help to discriminate between the various assumptions used in
theoretical models for describing the complex peeling of an adhesive tape. The
present imaging technique opens the door for an extensive study of the velocity
controlled stick-slip peeling of an adhesive tape that will allow to understand
the statistical complexity of the stick-slip in a stationary case.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 06:42:39 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Cortet",
"Pierre-Philippe",
"",
"Phys-ENS"
],
[
"Ciccotti",
"Matteo",
"",
"LCVN"
],
[
"Vanel",
"Loic",
"",
"Phys-ENS"
]
] |
0706.3565 | Anatoly Plotnikov | Anatoly D. Plotnikov | Experimental Algorithm for the Maximum Independent Set Problem | From author's book "Discrete mathematics",3-th ed., Moscow,New
knowledge,2007, 18 pages, 8 figures | Cybernetics and Systems Analysis: Volume 48, Issue 5 (2012), Page
673-680 | null | null | cs.DS | null | We develop an experimental algorithm for the exact solving of the maximum
independent set problem. The algorithm consecutively finds the maximal
independent sets of vertices in an arbitrary undirected graph such that the
next such set contains more elements than the preceding one. For this purpose,
we use a technique, developed by Ford and Fulkerson for the finite partially
ordered sets, in particular, their method for partition of a poset into the
minimum number of chains with finding the maximum antichain. In the process of
solving, a special digraph is constructed, and a conjecture is formulated
concerning properties of such digraph. This allows to offer of the solution
algorithm. Its theoretical estimation of running time equals to is $O(n^{8})$,
where $n$ is the number of graph vertices. The offered algorithm was tested by
a program on random graphs. The testing the confirms correctness of the
algorithm.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 06:45:49 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Jul 2007 02:16:12 GMT"
}
] | 2016-03-02T00:00:00 | [
[
"Plotnikov",
"Anatoly D.",
""
]
] |
0706.3566 | Zakaria Giunashvili | Zakaria Giunashvili | Algebraic definition of Holonomy on Poisson Manifold | 11 pages. Some sections concerning Lie algebra cohomomologies with
values in an endomorphism algebra are added | null | null | null | math.SG | null | We give an algebraic construction of connection on the symplectic leaves of
Poisson manifold, introduced in \cite{Ginzburg}. This construction is suitable
for the definition of the linearized holonomy on a regular symplectic
foliation.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 07:00:46 GMT"
},
{
"version": "v2",
"created": "Fri, 28 Sep 2007 12:41:11 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Giunashvili",
"Zakaria",
""
]
] |
0706.3567 | Pankaj Jain | Rajib Saha, Simon Prunet, Pankaj Jain, Tarun Souradeep | CMB anisotropy power spectrum using linear combinations of WMAP maps | 38 pages, 17 figures | Phys.Rev.D78:023003,2008 | 10.1103/PhysRevD.78.023003 | null | astro-ph | null | In recent years the goal of estimating different cosmological parameters
precisely has set new challenges in the effort to accurately measure the
angular power spectrum of CMB. This has required removal of foreground
contamination as well as detector noise bias with reliability and precision.
Recently, a novel {\em model-independent} method for the estimation of CMB
angular power spectrum solely from multi-frequency observations has been
proposed and implemented on the first year WMAP data by Saha et al. 2006. All
previous estimates of power spectrum of CMB are based upon foreground templates
using data sets from different experiments. However our methodology
demonstrates that {\em CMB angular spectrum can be reliably estimated with
precision from a self contained analysis of the WMAP data}. In this work we
provide a detailed description of this method. We also study and identify the
biases present in our power spectrum estimate. We apply our methodoly to
extract the power spectrum from the WMAP 1 year and 3 year data.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 06:51:11 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Saha",
"Rajib",
""
],
[
"Prunet",
"Simon",
""
],
[
"Jain",
"Pankaj",
""
],
[
"Souradeep",
"Tarun",
""
]
] |
0706.3568 | Ladygin Vladimir | M.Janek, T.Saito, V.P.Ladygin, T.Uesaka, M.Hatano, A.Yu.Isupov,
H.Kato, N.B.Ladygina, Y.Maeda, A.I.Malakhov, J.Nishikawa, T.Ohnishi,
H.Okamura, S.G.Reznikov, H.Sakai, S.Sakoda, N.Sakamoto, Y.Satou, K.Sekiguchi,
K.Suda, A.Tamii, N.Uchigashima, T.A.Vasiliev, K.Yako | Analyzing powers Ayy, Axx, Axz and Ay in the dd->3Hen reaction at 270
MeV | 8 pages, 7 figures, 4 tables. Submitted to EPJA | Eur.Phys.J.A33:39-46,2007 | 10.1140/epja/i2007-10411-9 | null | nucl-ex | null | The data on the tensor Ayy, Axx, Axz and vector Ay analyzing powers in the
dd->3Hen obtained at Td= 270 MeV in the angular range 0 - 110 degrees in the
c.m. are presented. The observed negative sign of the tensor analyzing powers
Ayy, Axx and Axz at small angles clearly demonstrate the sensitivity to the
ratio of the D and S wave component of the 3He wave function. However, the
one-nucleon exchange calculations by using the standard 3He wave functions have
failed to reproduce the strong variation of the tensor analyzing powers as a
function of the angle in the c.m.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 06:52:31 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Janek",
"M.",
""
],
[
"Saito",
"T.",
""
],
[
"Ladygin",
"V. P.",
""
],
[
"Uesaka",
"T.",
""
],
[
"Hatano",
"M.",
""
],
[
"Isupov",
"A. Yu.",
""
],
[
"Kato",
"H.",
""
],
[
"Ladygina",
"N. B.",
""
],
[
"Maeda",
"Y.",
""
],
[
"Malakhov",
"A. I.",
""
],
[
"Nishikawa",
"J.",
""
],
[
"Ohnishi",
"T.",
""
],
[
"Okamura",
"H.",
""
],
[
"Reznikov",
"S. G.",
""
],
[
"Sakai",
"H.",
""
],
[
"Sakoda",
"S.",
""
],
[
"Sakamoto",
"N.",
""
],
[
"Satou",
"Y.",
""
],
[
"Sekiguchi",
"K.",
""
],
[
"Suda",
"K.",
""
],
[
"Tamii",
"A.",
""
],
[
"Uchigashima",
"N.",
""
],
[
"Vasiliev",
"T. A.",
""
],
[
"Yako",
"K.",
""
]
] |
0706.3569 | Andrei Lobanov | Andrei Lobanov | Compact jets as probes for sub-parsec scale regions in AGN | AASLaTeX, 5 pages, 4 figures. Accepted in Astrophysics and Space
Science | Astrophys.SpaceSci.311:263-267,2007 | 10.1007/s10509-007-9530-8 | null | astro-ph | null | Compact relativistic jets in active galactic nuclei offer an effective tool
for investigating the physics of nuclear regions in galaxies. The emission
properties, dynamics, and evolution of jets in AGN are closely connected to the
characteristics of the central supermassive black hole, accretion disk and
broad-line region in active galaxies. Recent results from studies of the
nuclear regions in several active galaxies with prominent outflows are reviewed
in this contribution.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 06:55:45 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lobanov",
"Andrei",
""
]
] |
0706.3570 | Sabbah Claude | Claude Sabbah | An explicit stationary phase formula for the local formal
Fourier-Laplace transform | 22 pages, LaTeX file. Revised version to be published in the
Proceedings of the School and Workshop on the Geometry and Topology of
Singularities (L^e Fest). Few typos corrected and few remarks added | in Singularities I, Contemp. Math., vol. 474, Amer. Math. Soc.,
Providence, RI, 2008, p. 309-330 | null | null | math.AG math.CV | null | We give an explicit formula (i.e., a formal stationary phase formula) for the
local Fourier-Laplace transform of a formal germ of meromorphic connection of
one complex variable with a possibly irregular singularity. This is a complex
analogue of the formulas in the preprint math/0702436v1.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 06:56:08 GMT"
},
{
"version": "v2",
"created": "Thu, 10 Jan 2008 15:14:05 GMT"
}
] | 2011-01-04T00:00:00 | [
[
"Sabbah",
"Claude",
""
]
] |
0706.3571 | Toshiaki Kori | Tosiaki Kori | Chern-Simons pre-quantization over four-manifolds | arXiv admin note: text overlap with arXiv:math/0510268 | Differ.Geom.Appl.29:670-684,2011 | 10.1016/j.difgeo.2011.07.004 | null | math.SG math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce a pre-symplectic structure on the space of connections in a
G-principal bundle over a four-manifold and a Hamiltonian action on it of the
group of gauge transformations that are trivial on the boundary. The moment map
is given by the square of curvature so that the 0-level set is the space of
flat connections. Thus the moduli space of flat connections is endowed with a
pre-symplectic structure. In case when the four-manifold is null-cobordant we
shall construct, on the moduli space of connections, as well as on that of flat
connections, a hermitian line bundle with connection whose curvature is given
by the pre-symplectic form. This is the Chern-Simons pre-quantum line bundle.
The group of gauge transformations on the boundary of the base manifold acts on
the moduli space of flat connections by an infinitesimally symplectic way. When
the base manifold is a 4-dimensional disc we show that this action is lifted to
the pre-quantum line bundle by its abelian extension. The geometric description
of the latter is related to the 4-dimensional Wess-Zumino-Witten model. The
previous version of this arxiv text had several incoincidence with the
published article in the Differential Geometry and its Applications vol.29, so
the author corrected them.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 07:17:03 GMT"
},
{
"version": "v2",
"created": "Thu, 9 Oct 2014 01:29:31 GMT"
}
] | 2014-10-10T00:00:00 | [
[
"Kori",
"Tosiaki",
""
]
] |
0706.3572 | Jean-Christophe Pain | Jean-Christophe Pain | Quantum-statistical equation-of-state models of dense plasmas:
high-pressure Hugoniot shock adiabats | accepted in "Contributions to Plasma Physics" (2007) | null | 10.1002/ctpp.200710055 | null | physics.plasm-ph physics.gen-ph | null | We present a detailed comparison of two self-consistent equation-of-state
models which differ from their electronic contribution: the atom in a spherical
cell and the atom in a jellium of charges. It is shown that both models are
well suited for the calculation of Hugoniot shock adiabats in the high pressure
range (1 Mbar-10 Gbar), and that the atom-in-a-jellium model provides a better
treatment of pressure ionization. Comparisons with experimental data are also
presented. Shell effects on shock adiabats are reviewed in the light of these
models. They lead to additional features not only in the variations of pressure
versus density, but also in the variations of shock velocity versus particle
velocity. Moreover, such effects are found to be responsible for enhancement of
the electronic specific heat.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 07:38:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pain",
"Jean-Christophe",
""
]
] |
0706.3573 | Riccardo Borghi | Riccardo Borghi | Optical asymptotics via Weniger transformation | 4 pages, 1 figure | null | null | null | physics.optics physics.comp-ph | null | Starting from the resurgence equation discovered by Berry and Howls [M. V.
Berry and C. Howls "Hyperasymptotics for integrals with saddles," Proc. R. Soc.
Lond. A 434, 657-675 (1991)], the Weniger transformation is here proposed as a
natural, efficient, and straightforwardly implementable scheme for the
efficient asymptotics evaluation of a class of integrals occurring in several
areas of physics and, in particular, of optics. Preliminary numerical tests,
carried out on the Pearcey function, provide a direct comparison between the
performances of Weniger transformation and those of Hyperasymptotics, which
seems to corroborate the theoretical predictions. We believe that Weniger
transformation would be a very useful computational tool for the asymptotic
treatment of several optical problems.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 07:26:30 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Borghi",
"Riccardo",
""
]
] |
0706.3574 | Vol Evgenii D | E.D. Vol | The Characteristic Noise Induced by the Continious Measurements in
Classical Open Systems | 13 p., 0 fig | null | 10.1007/s10773-008-9812-0 | null | quant-ph | null | We proposed the modified version of quantum-mechanical theory of continuous
measurements for the case of classical open systems. In our approach the
influence of measurement on evolution of distribution function of an open
system is described by the Fokker-Planck equation of a special form. The
diffusion tensor of this equation is uniquely defined by a type of the measured
quantity. On the basis of the approach proposed the stationary states of the
linear dissipative systems, induced by measurements in them, are considered.
Also we demonstrate on the simple example, how in the conservative system,
consisting of noninteracting parts, measurement of the integral of motion
results in relaxation to the quasi-thermodynamic equilibrium between parts of
the system. The "temperature" of such state is determined by energy of the
system and by the mean value of measured integral of motion. PACS numbers:
03.65.Ta, 05.40.-a
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 07:26:32 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Vol",
"E. D.",
""
]
] |
0706.3575 | Mikhail Kalenkov | Mikhail S. Kalenkov and Andrei D. Zaikin | Crossed Andreev reflection at spin-active interfaces | 11 pages, 7 figures; figures 6 and 7 are corrected; version published
in Phys. Rev. B | Phys. Rev. B 76, 224506 (2007) | 10.1103/PhysRevB.76.224506 | null | cond-mat.supr-con | null | With the aid of the quasiclassical Eilenberger formalism we develop a theory
of non-local electron transport across three-terminal ballistic
normal-superconducting-normal (NSN) devices with spin-active NS interfaces. The
phenomenon of crossed Andreev reflection (CAR) is known to play the key role in
such transport. We demonstrate that CAR is highly sensitive to electron spins
and yields a rich variety of properties of non-local conductance which we
describe non-perturbatively at arbitrary voltages, temperature, spin-dependent
interface transmissions and their polarizations. Our results can be applied to
multi-terminal hybrid structures with normal, ferromagnetic and half-metallic
electrodes and can be directly tested in future experiments.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:13:26 GMT"
},
{
"version": "v2",
"created": "Sat, 8 Dec 2007 10:46:34 GMT"
}
] | 2010-01-21T00:00:00 | [
[
"Kalenkov",
"Mikhail S.",
""
],
[
"Zaikin",
"Andrei D.",
""
]
] |
0706.3576 | Hartmuth Arenh\"ovel | H. Arenhoevel | Coulomb effects in polarization transfer in elastic antiproton and
proton electron scattering at low energies | 10 pages, 7 figures Few typos corrected, accepted for publication in
Eur. Phys. J. A, few typos corrected, last sentence of conclusions changed | Eur.Phys.J.A39:133-135,2009 | 10.1140/epja/i2008-10704-5 | MKPH-T-07-06 | nucl-th | null | The influence of Coulomb distortion on the polarization transfer in elastic
proton and antiproton electron scattering at low energies is calculated in a
distorted wave Born approximation. For antiproton electron scattering Coulomb
effects reduce substantially the spin transfer cross section compared to the
plane wave Born approximation whereas for proton electron scattering they lead
to a dramatic increase for kinetic proton lab energies below about 20 keV.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 07:41:37 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Aug 2007 08:53:38 GMT"
},
{
"version": "v3",
"created": "Mon, 19 Nov 2007 09:35:25 GMT"
}
] | 2009-02-19T00:00:00 | [
[
"Arenhoevel",
"H.",
""
]
] |
0706.3577 | Matteo Conforti | Matteo Conforti, Fabio Baronio, Antonio Degasperis, Stefan Wabnitz | Parametric Frequency Conversion of Short Optical Pulses Controlled by a
CW Background | null | null | 10.1364/OE.15.012246 | null | physics.optics | null | We predict that parametric sum-frequency generation of an ultra-short pulse
may result from the mixing of an ultra-short optical pulse with a
quasi-continuous wave control. We analytically show that the intensity, time
duration and group velocity of the generated idler pulse may be controlled in a
stable manner by adjusting the intensity level of the background pump.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 07:50:22 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Conforti",
"Matteo",
""
],
[
"Baronio",
"Fabio",
""
],
[
"Degasperis",
"Antonio",
""
],
[
"Wabnitz",
"Stefan",
""
]
] |
0706.3578 | Yury Lyubarsky | Yury Lyubarsky and David Eichler | On the corona of magnetars | 23 pages, 2 fig. Submitted to ApJ | null | null | null | astro-ph | null | Slow dissipation of non-potential magnetic fields in the magnetosphere of the
magnetar is assumed to accelerate particles to hundreds MeV along the magnetic
field lines. We consider interaction of fast particles with the surface of the
magnetar. We argue that the collisionless dissipation does not work in the
atmosphere of the neutron star because the two-stream instability is stabilized
by the inhomogeneity of the atmosphere. Rather, the dominant dissipation
mechanism is collisional Landau levelexcitations followed by pair production
via the deexcitation gamma-rays ultimately leading to electrons with the energy
below the Landau energy. We show that, because of the effects of the
superstrong magnetic field, these electrons could emerge from the surface
carrying most of the original energy so that a hot corona arises with the
temperature of 1 - 2 MeV. This extended corona is better suited than a thin
atmosphere to convert most of the primary beam energy to non-thermal radiation
and, as we show, most of the coronal energy release is radiated away in the
hard X-ray and the soft gamma-ray bands by Comptonization and bremsstrahlung.
The radiation spectrum is a power-law with the photon index $1<\alpha<2$. The
model may account for the persistent hard X-ray emission discovered recently
from the soft gamma-ray repeaters and anomalous X-ray pulsars and predicts that
the radiation spectrum is extended into the MeV band.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 19:12:57 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Lyubarsky",
"Yury",
""
],
[
"Eichler",
"David",
""
]
] |
0706.3579 | Ivan Christov | Ivan P. Christov | Time-dependent quantum Monte Carlo and the stochastic quantization | 40 pages, 4 figures, replaced fig.4 | J. Chem. Phys. 127, 134110 (2007), with minor corrections | 10.1063/1.2779038 | null | physics.atom-ph | null | We examine the relation between the recently proposed time-dependent quantum
Monte Carlo (TDQMC) method and the principles of stochastic quantization. In
both TDQMC and stochastic quantization particle motion obeys stochastic
guidance equations to preserve quantum equilibrium. In this way the probability
density of the Monte Carlo particles corresponds to the modulus square of the
many-body wave function at all times. However, in TDQMC the motion of particles
and guide waves occurs in physical space unlike in stochastic quantization
where it occurs in configuration space. Hence the practical calculation of time
evolution of many-body fully correlated quantum systems becomes feasible within
the TDQMC methodology. We illustrate the TDQMC technique by calculating the
symmetric and antisymmetric ground state of a model one-dimensional Helium
atom, and the time evolution of the dipole moment when the atom is irradiated
by a strong ultrashort laser pulse.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 07:52:16 GMT"
},
{
"version": "v2",
"created": "Sun, 9 Dec 2007 12:36:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Christov",
"Ivan P.",
""
]
] |
0706.3580 | D. B. McReynolds | D. B. McReynolds | Cusps of Hilbert modular varieties | To appear in Mathematical Proceedings Cambridge Philosophical Society | Math. Proc. Cambridge Philos. Soc. 2008 (144), 749-759 | 10.1017/S0305004107001004 | null | math.GT math.DG | null | Motivated by a question of Hirzebruch on the possible topological types of
cusp cross-sections of Hilbert modular varieties, we give a necessary and
sufficient condition for a manifold M to be diffeomorphic to a cusp
cross-section of a Hilbert modular variety. Specialized to Hilbert modular
surfaces, this proves that every Sol 3-manifold is diffeomorphic to a cusp
cross-section of a (generalized) Hilbert modular surface. We also deduce an
obstruction to geometric bounding in this setting. Consequently, there exist
Sol 3-manifolds that cannot arise as a cusp cross-section of a 1-cusped
nonsingular Hilbert modular surface.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 16:21:33 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"McReynolds",
"D. B.",
""
]
] |
0706.3581 | Xiangcun Meng | X. Meng, X. Chen, Z. Han | The Impact of Type Ia Supernova Explosions on their Companions in Binary
System | 15 pages, 5 figures, accepted by PASJ | null | null | null | astro-ph | null | Using a simple analytic method, we calculate the impact effect between the
ejecta of a SN Ia and its companion to survey the influence of initial
parameters of the progenitor's system, which is useful for searching the
companion in a explosion remnant. The companion models are obtained from
Eggleton's evolution code.The results are divided into two groups based on mass
transfer stage. For a given condition, more hydrogen-rich material is stripped
from the envelope of a Hertzsprung-gap companion than that of a main-sequence
companion, while a larger kick velocity and a larger luminosity are gained for
a main-sequence companion. The kick velocity is too low to significantly affect
the final spatial velocity of the companion, which is mainly affected by the
initial parameters of the progenitor systems. The spatial velocity of the
stripped material has an upper limit within the range of 8000 - 9500 km/s,
which only depends on the total kinetic energy of the explosion.The stripped
mass, the ratio of the stripped mass to the companion mass and the kick
velocity of the companion all significantly depend on the initial companion
mass and orbital period. Our model may naturally explain the spatial velocity
of the star G in the remnant of Tycho's supernova, while an energy-loss
mechanism is needed to interpret its luminosity.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:14:37 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Meng",
"X.",
""
],
[
"Chen",
"X.",
""
],
[
"Han",
"Z.",
""
]
] |
0706.3582 | Alekos Vidras | Lev Aizenberg, Victor Gotlib, Alekos Vidras | Bohr and Rogosinski abscissas for ordinary Dirichlet series | null | null | null | null | math.CV math.CA | null | We prove that the abscissas of Bohr and Rogosinski for ordinary Dirichlet
series, mapping the right half-plane into the bounded convex domain $G\subset
\mathbb{C} $ are independent of the domain $G$. Furthermore, we obtain new
estimates about these abscissas.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:15:16 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Aizenberg",
"Lev",
""
],
[
"Gotlib",
"Victor",
""
],
[
"Vidras",
"Alekos",
""
]
] |
0706.3583 | Henrik Beuther | H. Beuther and T.K. Sridharan | Outflow and dense gas emission from massive Infrared Dark Clouds | 22 pages (ApJ referee style), 7 figures, accepted for ApJ | null | 10.1086/521142 | null | astro-ph | null | Infrared Dark Clouds are expected to harbor sources in different, very young
evolutionary stages. To better characterize these differences, we observed a
sample of 43 massive Infrared Dark Clouds, originally selected as candidate
high-mass starless cores, with the IRAM 30m telescope covering spectral line
tracers of low-density gas, high-density gas, molecular outflows/jets and
temperature effects. The SiO(2-1) observations reveal detections toward 18
sources. Assuming that SiO is exclusively produced by sputtering from dust
grains, this implies that at least in 40% of this sample star formation is
on-going. A broad range of SiO line-widths is observed (between 2.2 and
65km/s), and we discuss potential origins for this velocity spread. While the
low-density tracers 12CO(2-1) and 13CO(1-0) are detected in several velocity
components, the high-density tracer H13CO+(1--0) generally shows only a single
velocity component and is hence well suited for kinematic distance estimates of
IRDCs. Furthermore, the H13CO+ line-width is on average 1.5 times larger than
that of previously observed NH3(1,1). This is indicative of more motion at the
denser core centers, either due to turbulence or beginning star formation
activity. In addition, we detect CH3CN toward only six sources whereas CH3OH is
observed toward approximately 40% of the sample. Estimates of the CH3CN and
CH3OH abundances are low with average values of 1.2x10^{-10} and 4.3x10^{-10},
respectively. These results are consistent with chemical models at the earliest
evolutionary stages of high-mass star formation. Furthermore, the CH3OH
abundances compare well to recently reported values for low-mass starless
cores.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:25:26 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Beuther",
"H.",
""
],
[
"Sridharan",
"T. K.",
""
]
] |
0706.3584 | Jochen Wosnitza | R. Lortz, Y. Wang, A. Demuer, P.H.M. B\"ottger, B. Bergk, G.
Zwicknagl, Y. Nakazawa, J. Wosnitza | Calorimetric Evidence for a Fulde-Ferrell-Larkin-Ovchinnikov
Superconducting State in the Layered Organic Superconductor
\kappa$-(BEDT-TTF)$_2$Cu(NCS)$_2$ | 4pages, 3 figures | Phys. Rev. Lett. 99, 187002 (2007) | 10.1103/PhysRevLett.99.187002 | null | cond-mat.supr-con cond-mat.str-el | null | The specific heat of the layered organic superconductor $\kappa$-%
(BEDT-TTF)$_2$Cu(NCS)$_2$, where BEDT-TTF is bisethylenedithio-%
tetrathiafulvalene, has been studied in magnetic fields up to 28 T applied
perpendicular and parallel to the superconducting layers. In parallel fields
above 21 T, the superconducting transition becomes first order, which signals
that the Pauli-limiting field is reached. Instead of saturating at this field
value, the upper critical field increases sharply and a second first-order
transition line appears within the superconducting phase. Our results give
strong evidence that the phase, which separates the homogeneous superconducting
state from the normal state is a realization of a
Fulde-Ferrell-Larkin-Ovchinnikov state.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:30:25 GMT"
},
{
"version": "v2",
"created": "Tue, 30 Oct 2007 18:03:49 GMT"
}
] | 2007-10-30T00:00:00 | [
[
"Lortz",
"R.",
""
],
[
"Wang",
"Y.",
""
],
[
"Demuer",
"A.",
""
],
[
"Böttger",
"P. H. M.",
""
],
[
"Bergk",
"B.",
""
],
[
"Zwicknagl",
"G.",
""
],
[
"Nakazawa",
"Y.",
""
],
[
"Wosnitza",
"J.",
""
]
] |
0706.3585 | Masaki Satoh | Masaki Satoh, Sugumi Kanno and Jiro Soda | Circular Polarization of Primordial Gravitational Waves in
String-inspired Inflationary Cosmology | 11 pages, 7 figures, added new discussions, published version(v3),
added references(v4) | Phys.Rev.D77:023526,2008 | 10.1103/PhysRevD.77.023526 | KUNS-2125 | astro-ph gr-qc hep-th | null | We study a mechanism to produce the circular polarization of primordial
gravitational waves.
The circular polarization is generated during the super-inflation driven by
the Gauss-Bonnet term in the string-inspired cosmology. The instability in the
tensor mode caused by the Gauss-Bonnet term and the parity violation due to the
gravitational Chern-Simons term are the essential ingredients of the mechanism.
We also discuss detectability of the produced circular polarization of
gravitational waves. It turns out that the simple model of single-field
inflation contradicts CMB observations. To circumvent this difficulty, we
propose a two-field inflation model. In this two-field model, the circular
polarization of gravitational waves is created in the frequency range designed
by the Big-Bang Observer (BBO) or the deci-hertz gravitational-wave observatory
(DECIGO).
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:17:57 GMT"
},
{
"version": "v2",
"created": "Sun, 1 Jul 2007 16:43:15 GMT"
},
{
"version": "v3",
"created": "Wed, 13 Feb 2008 09:18:29 GMT"
},
{
"version": "v4",
"created": "Mon, 10 Mar 2008 12:09:40 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Satoh",
"Masaki",
""
],
[
"Kanno",
"Sugumi",
""
],
[
"Soda",
"Jiro",
""
]
] |
0706.3586 | Giuseppe De Risi | Giuseppe De Risi, Roy Maartens, Parampreet Singh | Graceful exit via polymerization of pre-big bang cosmology | 7 pages, 8 figures. Some clarifications added. To appear on Phys.
Rev. D | Phys.Rev.D76:103531,2007 | 10.1103/PhysRevD.76.103531 | IGPG-07/6-9 | hep-th gr-qc | null | We consider a phenomenological modification of the Pre Big Bang scenario
using ideas from the resolution of curvature singularities in Loop Quantum
Cosmology. We show that non-perturbative Loop modifications to the dynamics,
arising from the underlying polymer representation, can resolve the graceful
exit problem. The curvature and the dilaton energy stay finite at all times, in
both the string and Einstein frames. In the string frame, the dilaton tends to
a constant value at late times after the bounce.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 16:19:18 GMT"
},
{
"version": "v2",
"created": "Tue, 25 Sep 2007 09:08:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"De Risi",
"Giuseppe",
""
],
[
"Maartens",
"Roy",
""
],
[
"Singh",
"Parampreet",
""
]
] |
0706.3587 | Salvatore Capozziello | S. Capozziello | Dark energy models toward observational tests and data | 17 pages, 9 figures, Lectures for 42nd Karpacz Winter School of
Theoretical Physics: Current Mathematical Topics in Gravitation and
Cosmology, Ladek, Poland, 6-11 Feb 2006 | ECONF C0602061:04,2006; Int.J.Geom.Meth.Mod.Phys.4:53-78,2007 | 10.1142/S0219887807001886 | null | astro-ph | null | A huge amount of good quality astrophysical data converges towards the
picture of a spatially flat universe undergoing the today observed phase of
accelerated expansion. This new observational trend is commonly addressed as
Precision Cosmology. Despite of the quality of astrophysical surveys, the
nature of dark energy dominating the matter-energy content of the universe is
still unknown and a lot of different scenarios are viable candidates to explain
cosmic acceleration. Methods to test these cosmological models are based on
distance measurements and lookback time toward astronomical objects used as
standard candles. I discuss the characterizing parameters and constraints of
three different classes of dark energy models pointing out the related
degeneracy problem which is the signal that more data at low (z= 0- 1), medium
(1<z<10) and high (10 <z< 1000) redshift are needed to definitively select
realistic models.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:36:09 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Capozziello",
"S.",
""
]
] |
0706.3588 | Petre Dita | Petre Dita | A new type fit for the CKM matrix elements | 12 pages | null | null | null | hep-ph | null | The aim of the paper is to propose a new type of fits in terms of invariant
quantities for finding the entries of the CKM matrix from the quark sector, by
using the mathematical solution to the reconstruction problem of 3 x 3 unitary
matrices from experimental data, recently found. The necessity of this type of
fit comes from the compatibility conditions between the data and the
theoretical model formalised by the CKM matrix, which imply many strong
nonlinear conditions on moduli which all have to be satisfied in order to
obtain a unitary matrix.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:38:35 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Dita",
"Petre",
""
]
] |
0706.3589 | Janos Locsei | J. T. Locsei | Persistence of direction increases the drift velocity of run and tumble
chemotaxis | 17 pages, 5 figures | J. Math. Biol. 55, 2007, 41-60 | 10.1007/s00285-007-0080-z | null | q-bio.QM | null | Escherichia coli is a motile bacterium that moves up a chemoattractant
gradient by performing a biased random walk composed of alternating runs and
tumbles. Previous models of run and tumble chemotaxis neglect one or more
features of the motion, namely (i) a cell cannot directly detect a
chemoattractant gradient but rather makes temporal comparisons of
chemoattractant concentration, (ii) rather than being entirely random, tumbles
exhibit persistence of direction, meaning that the new direction after a tumble
is more likely to be in the forward hemisphere, and (iii) rotational Brownian
motion makes it impossible for an E. coli cell to swim in a straight line
during a run. This paper presents an analytic calculation of the chemotactic
drift velocity taking account of (i), (ii) and (iii), for weak chemotaxis. The
analytic results are verified by Monte Carlo simulation. The results reveal a
synergy between temporal comparisons and persistence that enhances the drift
velocity, while rotational Brownian motion reduces the drift velocity.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:42:01 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Locsei",
"J. T.",
""
]
] |
0706.3590 | Edmond Orignac | E. Orignac (ENS-Lyon), R. Citro (Salerno), S. Capponi (Toulouse), D.
Poilblanc (Toulouse) | Breathers and Raman scattering in a two-leg ladder with staggered
Dzialoshinskii-Moriya interaction | RevTeX 4, 14 pages, 11 EPS figures | Phys. Rev. B 76 144422 (2007) | 10.1103/PhysRevB.76.144422 | null | cond-mat.str-el | null | Recent experiments have revealed the role of staggered Dzialoshinskii-Moriya
interaction in the magnetized phase of an antiferromagnetic spin 1/2 two-leg
ladder compound under a uniform magnetic field. We derive a low energy
effective field theory describing a magnetized two-leg ladder with a weak
staggered Dzialoshinskii-Moriya interaction. This theory predicts the
persistence of the spin gap in the magnetized phase, in contrast to standard
two-leg ladders, and the presence of bound states in the excitation spectrum.
Such bound states are observable in Raman scattering measurements. These
results are then extended to intermediate Dzialoshinskii-Moriya interaction
using Exact Diagonalizations.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:45:04 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Orignac",
"E.",
"",
"ENS-Lyon"
],
[
"Citro",
"R.",
"",
"Salerno"
],
[
"Capponi",
"S.",
"",
"Toulouse"
],
[
"Poilblanc",
"D.",
"",
"Toulouse"
]
] |
0706.3591 | Marco Monni | M. Monni, I. Pallecchi, C. Ferdeghini, V. Ferrando, A. Floris, E.
Galleani d'Agliano, E. Lehmann, I. Sheikin, C. Tarantini, X.X. Xi, S.
Massidda, M. Putti | Probing the electron-phonon coupling in MgB2 through magnetoresistance
measurements in neutron irradiated thin films | 13 pages, 4 figures, 1 table | null | 10.1209/0295-5075/81/67006 | null | cond-mat.supr-con | null | We report magnetoresistance (MR) measurements on MgB2 and the corresponding
full account from ab-initio calculations; we suggest that this combination can
be a useful tool to probe electron- phonon coupling. We obtain good
quantitative agreement between high field measurements on neutron irradiated
epitaxial thin films and calculations within Bloch-Boltzmann transport theory
over a wide range of magnetic fields (0-28 T) and temperatures (40-300 K), and
as a function of the field orientation. The crossovers between in-plane and
out-of-plane MR, experimentally observed as a function of either disorder or
temperature are well reproduced indicating that disorder and interaction with
phonons strongly affect the scattering rate of s-carriers.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:51:39 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Monni",
"M.",
""
],
[
"Pallecchi",
"I.",
""
],
[
"Ferdeghini",
"C.",
""
],
[
"Ferrando",
"V.",
""
],
[
"Floris",
"A.",
""
],
[
"d'Agliano",
"E. Galleani",
""
],
[
"Lehmann",
"E.",
""
],
[
"Sheikin",
"I.",
""
],
[
"Tarantini",
"C.",
""
],
[
"Xi",
"X. X.",
""
],
[
"Massidda",
"S.",
""
],
[
"Putti",
"M.",
""
]
] |
0706.3592 | Jean-Christophe Pain | Jean-Christophe Pain | A model of dense-plasma atomic structure for equation-of-state
calculations | article in J. Phys. B: At. Mol. Opt. Phys | null | null | null | physics.atom-ph physics.plasm-ph | null | A model of dense plasmas relying on the superconfiguration approximation is
presented. In each superconfiguration the nucleus is totally screened by the
electrons in a Wigner-Seitz sphere (ion-sphere model). Superconfigurations of
the same charge are grouped into ions. It is shown that boundary values of the
wavefunctions play a crucial role in the form of the Virial theorem from which
the pressure formula is derived. Finally, a condition is presented and
discussed, which makes the ion-sphere model variational when bound electrons
are treated quantum-mechanically and free electrons quasi-classically.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:54:21 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Pain",
"Jean-Christophe",
""
]
] |
0706.3593 | Sascha P. Quanz | S. P. Quanz, Th. Henning, J. Bouwman, R. van Boekel, A. Juhasz, H.
Linz (all Max Planck Institute for Astronomy, Heidelberg/Germany), K.M.
Pontoppidan (California Institute of Technology, Pasadena/USA), F. Lahuis
(Leiden Observatory, Leiden/Netherlands; SRON Netherlands Institute for Space
Research, Groningen/Netherlands) | Evolution of dust and ice features around FU Orionis objects | accepted for publication in ApJ; 63 pages preprint style including 8
tables and 24 figures | null | 10.1086/521219 | null | astro-ph | null | (abridged) We present spectroscopy data for a sample of 14 FUors and 2 TTauri
stars observed with the Spitzer Space Telescope or with the Infrared Space
Observatory (ISO). Based on the appearance of the 10 micron silicate feature we
define 2 categories of FUors. Objects showing the silicate feature in
absorption (Category 1) are still embedded in a dusty and icy envelope. The
shape of the 10 micron silicate absorption bands is compared to typical dust
compositions of the interstellar medium and found to be in general agreement.
Only one object (RNO 1B) appears to be too rich in amorphous pyroxene dust, but
a superposed emission feature can explain the observed shape. We derive optical
depths and extinction values from the silicate band and additional ice bands at
6.0, 6.8 and 15.2 micron. In particular the analysis of the CO_2 ice band at
15.2 micron allows us to search for evidence for ice processing and constrains
whether the absorbing material is physically linked to the central object or in
the foreground. For objects showing the silicate feature in emission (Category
2), we argue that the emission comes from the surface layer of accretion disks.
Analyzing the dust composition reveals that significant grain growth has
already taken place within the accretion disks, but no clear indications for
crystallization are present. We discuss how these observational results can be
explained in the picture of a young, and highly active accretion disk. Finally,
a framework is proposed as to how the two categories of FUors can be understood
in a general paradigm of the evolution of young, low-mass stars. Only one
object (Parsamian 21) shows PAH emission features. Their shapes, however, are
often seen toward evolved stars and we question the object's status as a FUor
and discuss other possible classifications.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 08:57:02 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Quanz",
"S. P.",
"",
"all Max Planck Institute for Astronomy, Heidelberg/Germany"
],
[
"Henning",
"Th.",
"",
"all Max Planck Institute for Astronomy, Heidelberg/Germany"
],
[
"Bouwman",
"J.",
"",
"all Max Planck Institute for Astronomy, Heidelberg/Germany"
],
[
"van Boekel",
"R.",
"",
"all Max Planck Institute for Astronomy, Heidelberg/Germany"
],
[
"Juhasz",
"A.",
"",
"all Max Planck Institute for Astronomy, Heidelberg/Germany"
],
[
"Linz",
"H.",
"",
"all Max Planck Institute for Astronomy, Heidelberg/Germany"
],
[
"Pontoppidan",
"K. M.",
"",
"California Institute of Technology, Pasadena/USA"
],
[
"Lahuis",
"F.",
"",
"Leiden Observatory, Leiden/Netherlands; SRON Netherlands Institute for Space\n Research, Groningen/Netherlands"
]
] |
0706.3594 | Thierry Champel | Thierry Champel, Tomas L\"ofwander, Matthias Eschrig | 0-pi Transitions in a Superconductor/Chiral Ferromagnet/Superconductor
Junction induced by a Homogeneous Cycloidal Spiral | 4 pages, 4 figures; the derivation part has been reorganized + added
note and new references, published version | Physical Review Letters 100, 077003 (2008) | 10.1103/PhysRevLett.100.077003 | null | cond-mat.supr-con | null | We study the pi phase in a superconductor-ferromagnet-superconductor
Josephson junction, with a ferromagnet showing a cycloidal spiral spin
modulation with in-plane propagation vector. Our results reveal a high
sensitivity of the junction to the spiral order and indicate the presence of
0-pi quantum phase transitions as function of the spiral wave vector. We find
that the chiral magnetic order introduces chiral superconducting triplet pairs
that strongly influence the physics in such Josephson junctions, with potential
applications in nanoelectronics and spintronics.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:03:09 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Feb 2008 16:27:41 GMT"
}
] | 2008-02-21T00:00:00 | [
[
"Champel",
"Thierry",
""
],
[
"Löfwander",
"Tomas",
""
],
[
"Eschrig",
"Matthias",
""
]
] |
0706.3595 | Iskander A. Taimanov | I. A. Taimanov, S. P. Tsarev | Two-dimensional Schroedinger operators with fast decaying potential and
multidimensional $L_2$-kernel | 3 pages | Russian Mathematical Surveys 62:3 (2007), 631-633 | 10.1070/RM2007v062n03ABEH004423 | null | math-ph math.MP | null | Using Moutard transformations we show how explicit examples of
two-dimensional Schroedinger operators with fast decaying potential and
multidimensional $L_2$-kernel may be constructed
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 12:42:09 GMT"
}
] | 2019-05-22T00:00:00 | [
[
"Taimanov",
"I. A.",
""
],
[
"Tsarev",
"S. P.",
""
]
] |
0706.3596 | Marc Pradas Gene | Marc Pradas, Juan M. L\'opez and A. Hern\'andez-Machado | Time dependent couplings and crossover length scales in non-equilibrium
surface roughening | Accepted for publication in Physical Review E (Rapid Comm.) | Phys. Rev. E 76, 010102(R) (2007) | 10.1103/PhysRevE.76.010102 | null | cond-mat.stat-mech | null | We show that time dependent couplings may lead to nontrivial scaling
properties of the surface fluctuations of the asymptotic regime in
non-equilibrium kinetic roughening models . Three typical situations are
studied. In the case of a crossover between two different rough regimes, the
time-dependent coupling may result in anomalous scaling for scales above the
crossover length. In a different setting, for a crossover from a rough to
either a flat or damping regime, the time dependent crossover length may
conspire to produce a rough surface, despite the most relevant term tends to
flatten the surface. In addition, our analysis sheds light into an existing
debate in the problem of spontaneous imbibition, where time dependent couplings
naturally arise in theoretical models and experiments.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 16:24:30 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pradas",
"Marc",
""
],
[
"López",
"Juan M.",
""
],
[
"Hernández-Machado",
"A.",
""
]
] |
0706.3597 | Naoki Yoshida | Naoki Yoshida (Nagoya), Kazuyuki Omukai (NAOJ), Lars Hernquist (CfA) | Formation of Massive Primordial Stars in a Reionized Gas | Revised version. To appear in ApJL | Astrophysical Journal Letters 667 (2007) 117-120 | 10.1086/522202 | null | astro-ph | null | We use cosmological hydrodynamic simulations with unprecedented resolution to
study the formation of primordial stars in an ionized gas at high redshifts.
Our approach includes all the relevant atomic and molecular physics to follow
the thermal evolution of a prestellar gas cloud to very high densities of
~10^{18} cm^{-3}. We locate a star-forming gas cloud within a reionized region
in our cosmological simulation. The first run-away collapse is triggered when
the gas cloud's mass is ~40 Msun. We show that the cloud core remains stable
against chemo-thermal instability and also against gravitational deformation
throughout its evolution. Consequently, a single proto-stellar seed is formed,
which accretes the surrounding hot gas at the rate ~10^{-3} Msun/year. We carry
out proto-stellar evolution calculations using the inferred accretion rate. The
resulting mass of the star when it reaches the zero-age main sequence is M_ZAMS
~40 Msun. We argue that, since the obtained M_ZAMS is as large as the mass of
the collapsing parent cloud, the final stellar mass should be close to this
value. Such massive, rather than exceptionally massive, primordial stars are
expected to cause early chemical enrichment of the Universe by exploding as
black hole-forming super/hypernovae, and may also be progenitors of high
redshift gamma-ray bursts. The elemental abundance patterns of recently
discovered hyper metal-poor stars suggest that they might have been born from
the interstellar medium that was metal-enriched by supernovae of these massive
primordial stars.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 12:36:13 GMT"
},
{
"version": "v2",
"created": "Tue, 7 Aug 2007 16:30:56 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Yoshida",
"Naoki",
"",
"Nagoya"
],
[
"Omukai",
"Kazuyuki",
"",
"NAOJ"
],
[
"Hernquist",
"Lars",
"",
"CfA"
]
] |
0706.3598 | Julien Malzac | Julien Malzac | Jet disc coupling in black hole binaries | Invited talk at the Fifth Stromlo Symposium: Disks, Winds & Jets -
from Planets to Quasars. Accepted for publication in Astrophysics & Space
Science | Astrophys.SpaceSci.311:149-159,2007 | 10.1007/s10509-007-9558-9 | null | astro-ph | null | In the last decade multi-wavelength observations have demonstrated the
importance of jets in the energy output of accreting black hole binaries. The
observed correlations between the presence of a jet and the state of the
accretion flow provide important information on the coupling between accretion
and ejection processes. After a brief review of the properties of black hole
binaries, I illustrate the connection between accretion and ejection through
two particularly interesting examples. First, an INTEGRAL observation of Cygnus
X-1 during a 'mini-' state transition reveals disc jet coupling on time scales
of orders of hours. Second, the black hole XTEJ1118+480 shows complex
correlations between the X-ray and optical emission. Those correlations are
interpreted in terms of coupling between disc and jet on time scales of seconds
or less. Those observations are discussed in the framework of current models.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:21:26 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Malzac",
"Julien",
""
]
] |
0706.3599 | Jinn-Ouk Gong | Jinn-Ouk Gong | Generation of perturbation after multi-field inflation | 8 pages, 1 figure; (v2) 9 pages, discussions expanded, to appear in
Physics Letters B | Phys.Lett.B657:165-169,2007 | 10.1016/j.physletb.2007.10.024 | null | astro-ph gr-qc hep-ph hep-th | null | We explore a new possibility that some inflaton fields in multi-field
inflation models satisfy the observed value of the spectral index so that the
curvature perturbation generated by them through post-inflationary dynamics may
be relevant for the current observations. We illustrate this point using a
simple and reasonable multi-field chaotic inflation model motivated from string
theory. Possible non-Gaussianity and the tensor-to-scalar ratio are briefly
addressed.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:33:14 GMT"
},
{
"version": "v2",
"created": "Thu, 18 Oct 2007 17:15:41 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gong",
"Jinn-Ouk",
""
]
] |
0706.3600 | Anatoly Serebrov | A.P. Serebrov, E.B. Aleksandrov, N.A. Dovator, S.P. Dmitriev, A.K.
Fomin, P. Geltenbort, A.G. Kharitonov, I.A. Krasnoschekova, M.S. Lasakov,
A.N. Murashkin, G.E. Shmelev, V.E. Varlamov, A.V. Vassiljev, O.M. Zherebtsov,
O. Zimmer | Experimental search for neutron - mirror neutron oscillations using
storage of ultracold neutrons | 16 pages, 8 figures, 2 tables | Phys.Lett.B663:181-185,2008 | 10.1016/j.physletb.2008.04.014 | null | nucl-ex | null | The idea of a hidden sector of mirror partners of elementary particles has
attracted considerable interest as a possible candidate for dark matter.
Recently it was pointed out by Berezhiani and Bento that the present
experimental data cannot exclude the possibility of a rapid oscillation of the
neutron n to a mirror neutron n' with oscillation time much smaller than the
neutron lifetime. A dedicated search for vacuum transitions n->n' has to be
performed at weak magnetic field, where both states are degenerate. We report
the result of our experiment, which compares rates of ultracold neutrons after
storage at a weak magnetic field well below 20 nT and at a magnetic field
strong enough to suppress the seeked transitions. We obtain a new limit for the
oscillation time of n-n' transitions, tau_osc (90% C.L.) > 414 s. The
corresponding limit for the mixing energy of the normal and mirror neutron
states is delta_m (90% C.L.) < 1.5x10-18 eV.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 12:32:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Serebrov",
"A. P.",
""
],
[
"Aleksandrov",
"E. B.",
""
],
[
"Dovator",
"N. A.",
""
],
[
"Dmitriev",
"S. P.",
""
],
[
"Fomin",
"A. K.",
""
],
[
"Geltenbort",
"P.",
""
],
[
"Kharitonov",
"A. G.",
""
],
[
"Krasnoschekova",
"I. A.",
""
],
[
"Lasakov",
"M. S.",
""
],
[
"Murashkin",
"A. N.",
""
],
[
"Shmelev",
"G. E.",
""
],
[
"Varlamov",
"V. E.",
""
],
[
"Vassiljev",
"A. V.",
""
],
[
"Zherebtsov",
"O. M.",
""
],
[
"Zimmer",
"O.",
""
]
] |
0706.3601 | Oscar Iglesias | Oscar Iglesias, Amilcar Labarta and Xavier Batlle | Modelling exchange bias in core/shell nanoparticles | 7 pages, 3 figures. Contribution presented at HMM 2007 held at Napoli
4-6 June 2007. To be published in J. Phys. Condens. Matter | J. Phys. : Condens. Matter 19, 406232 (2007) | 10.1088/0953-8984/19/40/406232 | null | cond-mat.mtrl-sci | null | We present an atomistic model of a single nanoparticle with core/shell
structure that takes into account its lattice strucutre and spherical geometry,
and in which the values of microscopic parameters such as anisotropy and
exchange constants can be tuned in the core, shell and interfacial regions. By
means of Monte Carlo simulations of the hysteresis loops based on this model,
we have determined the range of microscopic parameters for which loop shifts
after field cooling can be observed. The study of the magnetic order of the
interfacial spins for different particles sizes and values of the interfacial
exchange coupling have allowed us to correlate the appearance of loop
asymmetries and vertical displacements to the existence of a fraction of
uncompensated spins at the shell interface that remain pinned during field
cycling, offering new insight on the microscopic origin of the experimental
phenomenology.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:38:48 GMT"
},
{
"version": "v2",
"created": "Mon, 30 Jul 2007 12:10:25 GMT"
},
{
"version": "v3",
"created": "Tue, 4 Sep 2007 11:24:56 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Iglesias",
"Oscar",
""
],
[
"Labarta",
"Amilcar",
""
],
[
"Batlle",
"Xavier",
""
]
] |
0706.3602 | Lucio Cirio | Lucio Cirio | Twisted noncommutative equivariant cohomology: Weil and Cartan models | 48 pages v3: several substantial changes and improvements | null | null | null | math.QA hep-th math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We propose Weil and Cartan models for the equivariant cohomology of
noncommutative spaces which carry a covariant action of Drinfel'd twisted
symmetries. The construction is suggested by the noncommutative Weil algebra of
Alekseev and Meinrenken; we show that one can implement a Drinfel'd twist of
their models in order to take into account the noncommutativity of the spaces
we are acting on.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:39:12 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jul 2007 15:04:03 GMT"
},
{
"version": "v3",
"created": "Tue, 13 Jan 2009 14:08:30 GMT"
}
] | 2009-01-13T00:00:00 | [
[
"Cirio",
"Lucio",
""
]
] |
0706.3603 | Pierre-Henri Chavanis | Pierre-Henri Chavanis | Critical mass of bacterial populations and critical temperature of
self-gravitating Brownian particles in two dimensions | In press | Physica A, 384, 392 (2007) | 10.1016/j.physa.2007.03.056 | null | physics.bio-ph q-bio.CB | null | We show that the critical mass M_c=8\pi of bacterial populations in two
dimensions in the chemotactic problem is the counterpart of the critical
temperature T_c=GMm/4k_B of self-gravitating Brownian particles in
two-dimensional gravity. We obtain these critical values by using the Virial
theorem or by considering stationary solutions of the Keller-Segel model and
Smoluchowski-Poisson system. We also consider the case of one dimensional
systems and develop the connection with the Burgers equation. Finally, we
discuss the evolution of the system as a function of M or T in bounded and
unbounded domains in dimensions d=1, 2 and 3 and show the specificities of each
dimension. This paper aims to point out the numerous analogies between
bacterial populations, self-gravitating Brownian particles and, occasionally,
two-dimensional vortices.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:39:58 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Chavanis",
"Pierre-Henri",
""
]
] |
0706.3604 | Michael Bohn | Michael Bohn | An introduction to Seiberg-Witten theory on closed 3-manifolds | diploma thesis written in 2002/03, 184 pages, 10 figures, uses dcpic | null | null | null | math.GT | null | This is a version of the author's diploma thesis written at the University of
Cologne in 2002/03. The topic is the construction of Seiberg-Witten invariants
of closed 3-manifolds. In analogy to the four dimensional case, the structure
of the moduli space is investigated. The Seiberg-Witten invariants are defined
and their behaviour under deformation of the Riemannian metric is analyzed.
Since it is essentially an exposition of results which were already known
during the time of writing, the thesis has not been published. In particular,
the author does not claim any originality concerning the results. Moreover, new
developments of the theory are not included. However, the detailed
account--together with the appendices on the required functional analytic and
geometric background--might be of interest for people starting to work in the
area of gauge field theory.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:42:45 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Bohn",
"Michael",
""
]
] |
0706.3605 | Gabor Takacs | B. Pozsgay and G. Takacs | Form factors in finite volume II:disconnected terms and finite
temperature correlators | 44 pages, 16 eps figures, LaTeX2e file | Nucl.Phys.B788:209-251,2008 | 10.1016/j.nuclphysb.2007.07.008 | ITP-Budapest Report No. 635 | hep-th cond-mat.other hep-lat | null | Continuing the investigation started in a previous work, we consider form
factors of integrable quantum field theories in finite volume, extending our
investigation to matrix elements with disconnected pieces. Numerical
verification of our results is provided by truncated conformal space approach.
Such matrix elements are important in computing finite temperature correlation
functions, and we give a new method for generating a low temperature expansion,
which we test for the one-point function up to third order.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:44:39 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Pozsgay",
"B.",
""
],
[
"Takacs",
"G.",
""
]
] |
0706.3606 | Alexey Lyashenko | A. V. Lyashenko, A. Breskin, R. Chechik, J. F. C. A. Veloso, J. M. F.
Dos Santos, F. D. Amaro | Further progress in ion back-flow reduction with patterned gaseous
hole-multipliers | 17 pages, 11 figures, published in JINST | JINST2:P08004,2007 | 10.1088/1748-0221/2/08/P08004 | null | physics.ins-det physics.med-ph | null | A new idea on electrostatic deviation and capture of back-drifting
avalanche-ions in cascaded gaseous hole-multipliers is presented. It involves a
flipped reversed-bias Micro-Hole & Strip Plate (F-R-MHSP) element, the strips
of which are facing the drift region of the multiplier. The ions, originating
from successive multiplication stages, are efficiently deviated and captured by
such electrode. Experimental results are provided comparing the ion-blocking
capability of the F-R-MHSP to that of the reversed-bias Micro-Hole & Strip
Plate (R-MHSP) and the Gas Electron Multiplier (GEM). Best ion-blocking results
in cascaded hole-multipliers were reached with a detector having the F-R-MHSP
as the first multiplication element. A three-element F-R-MHSP/GEM/MHSP cascaded
multiplier operated in atmospheric-pressure Ar/CH4 (95/5), at total gain of
~10^{5}, yielded ion back-flow fractions of 3*10^{-4} and 1.5*10^{-4}, at drift
fields of 0.5 and 0.2 kV/cm, respectively. We describe the F-R-MHSP concept and
the relevance of the obtained ion back-flow fractions to various applications;
further ideas are also discussed.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 14:24:59 GMT"
},
{
"version": "v2",
"created": "Tue, 14 Aug 2007 13:14:13 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lyashenko",
"A. V.",
""
],
[
"Breskin",
"A.",
""
],
[
"Chechik",
"R.",
""
],
[
"Veloso",
"J. F. C. A.",
""
],
[
"Santos",
"J. M. F. Dos",
""
],
[
"Amaro",
"F. D.",
""
]
] |
0706.3607 | Mehmet Kadiroglu | Mehmet Kadiroglu, Jochen Gemmer | Boltzmann equation approach to transport in finite modular quantum
systems | null | Phys. Rev. B 76, 024306 (2007) | 10.1103/PhysRevB.76.024306 | null | cond-mat.stat-mech | null | We investigate the transport behavior of finite modular quantum systems. Such
systems have recently been analyzed by different methods. These approaches
indicate diffusive behavior even and especially for finite systems. Inspired by
these results we analyze analytically and numerically if and in which sense the
dynamics of those systems are in agreement with an appropriate Boltzmann
equation. We find that the transport behavior of a certain type of finite
modular quantum systems may indeed be described in terms of a Boltzmann
equation. However, the applicability of the Boltzmann equation appears to be
rather limited to a very specific type of model.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 09:59:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kadiroglu",
"Mehmet",
""
],
[
"Gemmer",
"Jochen",
""
]
] |
0706.3608 | Frank Loray | Frank Loray (IRMAR), David Mar\`in | Projective structures and projective bundles over compact Riemann
surfaces | null | null | null | null | math.CA math.AG math.DG | null | A projective structure on a compact Riemann surface X of genus g is given by
an atlas with transition functions in PGL(2,C). Equivalently, a projective
structure is given by a projective sl(2,C)-bundle over X equipped with a
section s and a foliation F which is both transversal to the fibers and the
section s. From this latter geometric bundle picture, we survey on classical
problems and results on projective structures. We will give a complete
description of projective (actually affine) structures on the torus with an
explicit versal family of foliated bundle picture.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 10:01:29 GMT"
}
] | 2007-06-26T00:00:00 | [
[
"Loray",
"Frank",
"",
"IRMAR"
],
[
"Marìn",
"David",
""
]
] |
0706.3609 | Ferenc Muranyi | F. Muranyi, G. Urbanik, V. Kataev and B. Buechner | Electron Spin Dynamics of the Superconductor CaC6 probed by ESR | 4 pages, 3 figures | null | 10.1103/PhysRevB.77.024507 | null | cond-mat.supr-con | null | Conduction Electron Spin Resonance (CESR) was measured on a thick slab of
CaC6 in the normal and superconducting state. A surprising increase of the CESR
intensity below Tc can not be explained by the theoretically predicted change
in spin susceptibility. It is interpreted as a vortex enhanced increase of the
effective skin depth. Non-linear microwave absorption measurements in the
superconducting state describe CaC6 as an anisotropic BCS superconductor. The
study of the spin dynamics in the superconducting state and the discovery of
the vortex enhanced increase of the skin depth poses a challenge to theory to
provide a comprehensive description of the observed phenomena. CESR data in the
normal state characterize CaC6 as a three-dimensional (3D) metal. The analysis
suggests that the scattering of conduction electrons is dominated by impurities
and supports the description of superconductivity in the dirty limit.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 10:13:19 GMT"
},
{
"version": "v2",
"created": "Wed, 24 Oct 2007 08:12:33 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Muranyi",
"F.",
""
],
[
"Urbanik",
"G.",
""
],
[
"Kataev",
"V.",
""
],
[
"Buechner",
"B.",
""
]
] |
0706.3610 | Dirk Kadau | Dirk Kadau, Alfred Hucht, Dietrich E. Wolf | Magnetic friction in Ising spin systems | 4 pages, 4 figures | Phys. Rev. Lett. 101, 137205 (2008) | 10.1103/PhysRevLett.101.137205 | null | cond-mat.stat-mech cond-mat.other | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A new contribution to friction is predicted to occur in systems with magnetic
correlations: Tangential relative motion of two Ising spin systems pumps energy
into the magnetic degrees of freedom. This leads to a friction force
proportional to the area of contact. The velocity and temperature dependence of
this force are investigated. Magnetic friction is strongest near the critical
temperature, below which the spin systems order spontaneously.
Antiferromagnetic coupling leads to stronger friction than ferromagnetic
coupling with the same exchange constant. The basic dissipation mechanism is
explained. If the coupling of the spin system to the heat bath is weak, a
surprising effect is observed in the ordered phase: The relative motion acts
like a heat pump cooling the spins in the vicinity of the friction surface.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 10:16:16 GMT"
},
{
"version": "v2",
"created": "Mon, 13 Oct 2008 09:48:37 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kadau",
"Dirk",
""
],
[
"Hucht",
"Alfred",
""
],
[
"Wolf",
"Dietrich E.",
""
]
] |
0706.3611 | Brian M. Andersen | Brian M. Andersen and G. M. Bruun | Magnetic and superfluid phases of confined fermions in two-dimensional
optical lattices | 4 pages, 3 figures | Phys. Rev. A 76, 041602(R) (2007) | 10.1103/PhysRevA.76.041602 | null | cond-mat.str-el cond-mat.supr-con | null | We examine antiferromagnetic and d-wave superfluid phases of cold fermionic
atoms with repulsive interactions in a two-dimensional optical lattice combined
with a harmonic trapping potential. For experimentally realistic parameters,
the trapping potential leads to the coexistence of magnetic and superfluid
ordered phases with the normal phase. We study the intriguing shell structures
arising from the competition between the magnetic and superfluid order as a
function of the filling fraction. In certain cases antiferromagnetism induce
superfluidity by charge redistributions. We furthermore demonstrate how these
shell structures can be detected as distinct anti-bunching dips and pairing
peaks in the density-density correlation function probed in expansion
experiments.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 10:21:02 GMT"
},
{
"version": "v2",
"created": "Mon, 22 Oct 2007 08:00:23 GMT"
}
] | 2007-10-22T00:00:00 | [
[
"Andersen",
"Brian M.",
""
],
[
"Bruun",
"G. M.",
""
]
] |
0706.3612 | Dimitris Tsomokos | D.I. Tsomokos, J.J. Garcia-Ripoll, N.R. Cooper, J.K. Pachos | Chiral entanglement in triangular lattice models | 9 pages, 7 figures, revised with more numerical results and further
discussions | Phys. Rev. A 77, 012106 (2008) | 10.1103/PhysRevA.77.012106 | null | quant-ph cond-mat.str-el | null | We consider the low energy spectrum of spin-1/2 two-dimensional triangular
lattice models subject to a ferromagnetic Heisenberg interaction and a three
spin chiral interaction of variable strength. Initially, we consider quasi-one
dimensional ladder systems of various geometries. Analytical results are
derived that yield the behavior of the ground states, their energies and the
transition points. The entanglement properties of the ground state of these
models are examined and we find that the entanglement depends on the lattice
geometry due to frustration effects. To this end, the chirality of a given
quantum state is used as a witness of tripartite entanglement. Finally, the two
dimensional model is investigated numerically by means of exact diagonalization
and indications are presented that the low energy sector is a chiral spin
liquid.
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 10:23:52 GMT"
},
{
"version": "v2",
"created": "Fri, 9 Nov 2007 03:09:37 GMT"
}
] | 2008-01-20T00:00:00 | [
[
"Tsomokos",
"D. I.",
""
],
[
"Garcia-Ripoll",
"J. J.",
""
],
[
"Cooper",
"N. R.",
""
],
[
"Pachos",
"J. K.",
""
]
] |
0706.3613 | Franco D'Orazio | F. Ricci, S. Picozzi, A. Continenza, F. D'Orazio, F. Lucari, K.
Westerholt, M. Kim, and A. J. Freeman | Optical and magneto-optical properties of ferromagnetic full-Heusler
films: experiments and first-principles calculations | 20 pages, including 6 figures and 1 table. 40 refs. To be published
in Phys. Rev. B | null | 10.1103/PhysRevB.76.014425 | null | cond-mat.mtrl-sci | null | We report a joint theoretical and experimental study focused on understanding
the optical and magneto-optical properties of Co-based full-Heusler compounds.
We show that magneto-optical spectra calculated within ab-initio density
functional theory are able to uniquely identify the features of the
experimental spectra in terms of spin resolved electronic transitions. As
expected for 3d-based magnets, we find that the largest Kerr rotation for these
alloys is of the order of 0.3o in polar geometry. In addition, we demonstrate
that (i) multilayered structures have to be carefully handled in the
theoretical calculations in order to improve the agreement with experiments,
and (ii) combined theoretical and experimental investigations constitute a
powerful approach to designing new materials for magneto-optical and
spin-related applications
| [
{
"version": "v1",
"created": "Mon, 25 Jun 2007 10:24:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ricci",
"F.",
""
],
[
"Picozzi",
"S.",
""
],
[
"Continenza",
"A.",
""
],
[
"D'Orazio",
"F.",
""
],
[
"Lucari",
"F.",
""
],
[
"Westerholt",
"K.",
""
],
[
"Kim",
"M.",
""
],
[
"Freeman",
"A. J.",
""
]
] |
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