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| versions
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timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0707.1730 | Seokcheon Lee | Seokcheon Lee and Kin-Wang Ng | Can Strong Gravitational Lensing Constrain Dark Energy? | 15 pages, 13 figures, Accepted in PRD | Phys.Rev.D76:043518,2007 | 10.1103/PhysRevD.76.043518 | null | astro-ph | null | We discuss the ratio of the angular diameter distances from the source to the
lens, $D_{ds}$, and to the observer at present, $D_{s}$, for various dark
energy models. It is well known that the difference of $D_s$s between the
models is apparent and this quantity is used for the analysis of Type Ia
supernovae. However we investigate the difference between the ratio of the
angular diameter distances for a cosmological constant,
$(D_{ds}/D_{s})^{\Lambda}$ and that for other dark energy models,
$(D_{ds}/D_{s})^{\rm{other}}$ in this paper. It has been known that there is
lens model degeneracy in using strong gravitational lensing. Thus, we
investigate the model independent observable quantity, Einstein radius
($\theta_E$), which is proportional to both $D_{ds}/D_s$ and velocity
dispersion squared, $\sigma_v^2$. $D_{ds}/D_s$ values depend on the parameters
of each dark energy model individually. However, $(D_{ds}/D_s)^{\Lambda} -
(D_{ds}/D_{s})^{\rm{other}}$ for the various dark energy models, is well within
the error of $\sigma_v$ for most of the parameter spaces of the dark energy
models. Thus, a single strong gravitational lensing by use of the Einstein
radius may not be a proper method to investigate the property of dark energy.
However, better understanding to the mass profile of clusters in the future or
other methods related to arc statistics rather than the distances may be used
for constraints on dark energy.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 03:50:10 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Lee",
"Seokcheon",
""
],
[
"Ng",
"Kin-Wang",
""
]
] |
0707.1731 | Valery Terebizh | V.Yu. Terebizh | A purely reflective large wide-field telescope | 14 pages, 6 figures; new examples added | null | 10.3103/S0190271708010245 | null | astro-ph | null | Two versions of a fast, purely reflective Paul-Baker type telescope are
discussed, each with an 8.4-m aperture, 3 deg diameter flat field and f/1.25
focal ratio.
The first version is based on a common, even asphere type of surface with
zero conic constant. The primary and tertiary mirrors are 6th order aspheres,
while the secondary mirror is an 8th order asphere (referred to here for
brevity, as the 6/8/6 configuration). The D_80 diameter of a star image varies
from 0''.18 on the optical axis up to 0''.27 at the edge of the field (9.3-13.5
mcm).
The second version of the telescope is based on a polysag surface type which
uses a polynomial expansion in the sag z, r^2 = 2R_0z - (1+b)z^2 + a_3 z^3 +
a_4 z^4 + ... + a_N z^N, instead of the common form of an aspheric surface.
This approach results in somewhat better images, with D_80 ranging from 0''.16
to 0''.23, using a lower-order 3/4/3 combination of powers for the mirror
surfaces. An additional example with 3.5-m aperture, 3.5 deg diameter flat
field, and f/1.25 focal ratio featuring near-diffraction-limited image quality
is also presented.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 04:00:10 GMT"
},
{
"version": "v2",
"created": "Wed, 31 Oct 2007 08:26:28 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Terebizh",
"V. Yu.",
""
]
] |
0707.1732 | Luis Octavio Silva Pereyra | Luis O. Silva and Ricardo Weder | The Two-Spectra Inverse Problem for Semi-Infinite Jacobi Matrices in The
Limit-Circle Case | 26 pages. Changes in the presentation of some results | Math. Phys. Anal. Geom. (2008) 11: 131--154 | 10.1007/s11040-008-9044-9 | null | math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a technique for reconstructing a semi-infinite Jacobi operator in
the limit circle case from the spectra of two different self-adjoint
extensions. Moreover, we give necessary and sufficient conditions for two real
sequences to be the spectra of two different self-adjoint extensions of a
Jacobi operator in the limit circle case.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 04:16:34 GMT"
},
{
"version": "v2",
"created": "Sat, 13 Sep 2008 01:40:55 GMT"
}
] | 2008-09-13T00:00:00 | [
[
"Silva",
"Luis O.",
""
],
[
"Weder",
"Ricardo",
""
]
] |
0707.1733 | Toshiaki Shoji | Toshiaki Shoji and Kentaro Wada | Cyclotomic $q$-Schur algebras associated to the Ariki-Koike algebra | 43 pages | null | null | null | math.RT math.QA | null | Let $S$ be the cyclotomic $q$-Schur algebra associated to the Ariki-Koike
algebra $H_{n,r}$ of rank $n$, introduced by Dipper-James-Mathas. For each $p =
(r_1, ..., r_g)$ such that $r_1 + ... + r_g = r$, we define a subalgebra $S^p$
of $S$ and its quotient algebra $\bar S^p$. It is shown that $S^p$ is a
standardly based algebra and $\bar S^p$ is a cellular algebra. By making use of
these algebras, we show that certain decomposition numbers for $S$ can be
expressed as a product of decomposition numbers for cyclotomic $q$-Schur
algebras associated to smaller Ariki_koike algebras $H_{n_k,r_k}$.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 04:16:41 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Shoji",
"Toshiaki",
""
],
[
"Wada",
"Kentaro",
""
]
] |
0707.1734 | L. C. Garcia de Andrade | L.C. Garcia de Andrade | Kinematic fast cosmic dynamos in non-inflationary phases of ellipsoidal
universe | null | null | null | null | gr-qc | null | Cosmic kinematic fast dynamo is found in non-inflationary phases of an
ellipsoidal anisotropic cosmological metric background solution of Einstein
field equations of general relativity. The magnetic field is amplified inside
the universe and spatially periodically. A finite resistivity is assumed, and a
nonsingular flow velocity is aligned with the magnetic field which is
orthogonal to a plane which is analog to a galactic plane in astrophysics.
Magnetic field components is stretched along the z-direction and a cosmic
dynamo is created in the spirit of Zeldovich stretch, twist and fold (STF)
dynamo generation mechanism. In the inflationary phase of the planar symmetric
universe, the primordial magnetic field decays and the galactic plane expands
as a de Sitter $(2+1)-spacetime$ and the eccentricity of the ellipsoidal
universe, tends to vanish with inflation. We may conclude that, as far as the
present model is concerned, anti-dynamos are obtained in inflationary phases.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 04:52:49 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"de Andrade",
"L. C. Garcia",
""
]
] |
0707.1735 | Yuki Adachi | Yuki Adachi, C.S. Lim and Nobuhito Maru | Finite Anomalous Magnetic Moment in the Gauge-Higgs Unification | 12 pages, 2 eps files, final version to appear in PRD | Phys.Rev.D76:075009,2007 | 10.1103/PhysRevD.76.075009 | KOBE-TH-07-05 | hep-ph | null | We show that the anomalous magnetic moment of fermion in the gauge-Higgs
unification is finite in any spacetime dimensions, which is a new predictive
physical observable similar to the Higgs mass.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 04:57:18 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Sep 2007 01:59:05 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Adachi",
"Yuki",
""
],
[
"Lim",
"C. S.",
""
],
[
"Maru",
"Nobuhito",
""
]
] |
0707.1736 | Xurong Chen | Xurong Chen | Spiral Wave Solutions of One-dimensional Ginzburg-Landau Equation By
Extended F-expansion Method | 5 pages, no figure | null | null | null | nlin.SI | null | The one-dimensional Ginzburg-Landau (GL) Equation is considered. We use the
recently developed extended F-expansion method to obtain spiral wave solution
of one-dimensional GL Equation.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 05:16:17 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Chen",
"Xurong",
""
]
] |
0707.1737 | Manvelyan Ruben | Ruben Manvelyan, Karapet Mkrtchyan and Ruben Mkrtchyan | Conformal invariant powers of the Laplacian, Fefferman-Graham ambient
metric and Ricci gauging | 15 pages, Latex, v.2 references added, v.3 ref. added, to appear in
Phys. Lett. B | Phys.Lett.B657:112-119,2007 | 10.1016/j.physletb.2007.10.014 | null | hep-th | null | The hierarchy of conformally invariant k-th powers of the Laplacian acting on
a scalar field with scaling dimensions $\Delta_{(k)}=k-d/2$, k=1,2,3 as
obtained in the recent work [1] is rederived using the Fefferman-Graham d+2
dimensional ambient space approach. The corresponding mysterious "holographic"
structure of these operators is clarified. We explore also the d+2 dimensional
ambient space origin of the Ricci gauging procedure proposed by A. Iorio, L.
O'Raifeartaigh, I. Sachs and C. Wiesendanger as another method of constructing
the Weyl invariant Lagrangians. The corresponding \emph{gauged} ambient metric,
Fefferman-Graham expansion and extended Penrose-Brown-Henneaux transformations
are proposed and analyzed.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 05:59:39 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Jul 2007 09:24:21 GMT"
},
{
"version": "v3",
"created": "Wed, 10 Oct 2007 10:51:06 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Manvelyan",
"Ruben",
""
],
[
"Mkrtchyan",
"Karapet",
""
],
[
"Mkrtchyan",
"Ruben",
""
]
] |
0707.1738 | Yuri Prokhorov | Yuri G. Prokhorov | Fields of invariants of finite linear groups | 27 pages, latex, submitted to Progress in Mathematics, "Rationality
problems" | Cohomological and Geometric Approaches to Rationality Problems.
New Perspectives, Birkh\"auser, 2010, 282 | null | null | math.AG | null | The survey is devoted to the rationality question of finite linear groups. We
concentrate on lower-dimensional cases, especially on the case of dimension
four.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 06:05:12 GMT"
},
{
"version": "v2",
"created": "Sun, 4 Nov 2007 10:13:58 GMT"
}
] | 2010-04-26T00:00:00 | [
[
"Prokhorov",
"Yuri G.",
""
]
] |
0707.1739 | Reza Rashidi Far | Reza Rashidi Far, Tamer Oraby, Wlodzimierz Bryc and Roland Speicher | On slow-fading non-separable correlation MIMO systems | 24 pages and 3 figures | IEEE Trans. Information Theory, Vol. 54, No. 2, pp.544-553, Feb.
2008 | null | null | cs.IT math.IT | null | In a frequency selective slow-fading channel in a MIMO system, the channel
matrix is of the form of a block matrix. We propose a method to calculate the
limit of the eigenvalue distribution of block matrices if the size of the
blocks tends to infinity. We will also calculate the asymptotic eigenvalue
distribution of $HH^*$, where the entries of $H$ are jointly Gaussian, with a
correlation of the form $E[h_{pj}\bar h_{qk}]= \sum_{s=1}^t
\Psi^{(s)}_{jk}\hat\Psi^{(s)}_{pq}$ (where $t$ is fixed and does not increase
with the size of the matrix). We will use an operator-valued free probability
approach to achieve this goal. Using this method, we derive a system of
equations, which can be solved numerically to compute the desired eigenvalue
distribution.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 06:29:58 GMT"
}
] | 2008-09-02T00:00:00 | [
[
"Far",
"Reza Rashidi",
""
],
[
"Oraby",
"Tamer",
""
],
[
"Bryc",
"Wlodzimierz",
""
],
[
"Speicher",
"Roland",
""
]
] |
0707.1740 | Miguel Avillez | Miguel A. de Avillez (U. Evora, Portugal and U. Vienna, Austria) and
Dieter Breitschwerdt (U. Vienna, Austria) | The Generation and Dissipation of Interstellar Turbulence - Results from
Large Scale High Resolution Simulations | Five pages and three figures. Accepted for publication in
Astrophysical Journal (Letters) | null | 10.1086/521222 | null | astro-ph | null | We study, by means of adaptive mesh refinement hydro- and
magnetohydrodynamical simulations that cover a wide range of scales (from kpc
to sub-parsec), the dimension of the most dissipative structures and the
injection scale of the turbulent interstellar gas, which we find to be about 75
pc, in agreement with observations. This is however smaller than the average
size of superbubbles, but consistent with significant density and pressure
changes in the ISM, which leads to the break-up of bubbles locally and hence to
injection of turbulence. The scalings of the structure functions are consistent
with log-Poisson statistics of supersonic turbulence where energy is dissipated
mainly through shocks. Our simulations are different from previous ones by
other authors as (i) we do not assume an isothermal gas, but have temperature
variations of several orders of magnitude and (ii) we have no artificial
forcing of the fluid with some ad hoc Fourier spectrum, but drive turbulence by
stellar explosions at the Galactic rate, self-regulated by density and
temperature thresholds imposed on the ISM gas.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 06:44:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"de Avillez",
"Miguel A.",
"",
"U. Evora, Portugal and U. Vienna, Austria"
],
[
"Breitschwerdt",
"Dieter",
"",
"U. Vienna, Austria"
]
] |
0707.1741 | Dietrich Stauffer | Dietrich Stauffer and Karl-Heinz Lampe | Computer Simulation of Host and two Parasite Species with Ageing | 6 pages including all figures, draft for Vie et Milieu | null | null | null | q-bio.PE | null | The possible coexistence of one host, one aggressive parasite and one
non-lethal parasite is simulated using the Penna model of biological ageing. If
the aggressive parasites survive the difficult initial times where they have to
adjust genetically to the proper host age, all three species may survive,
though the host number may be diminished by increasing parasite aggressivity.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:22:19 GMT"
},
{
"version": "v2",
"created": "Thu, 31 Jan 2008 18:35:36 GMT"
}
] | 2008-01-31T00:00:00 | [
[
"Stauffer",
"Dietrich",
""
],
[
"Lampe",
"Karl-Heinz",
""
]
] |
0707.1742 | Atsushi Shiho | Atsushi Shiho | Relative log convergent cohomology and relative rigid cohomology I | 69 pages. Errors and typos fixed | null | null | null | math.NT math.AG | null | In this paper, we develop the theory of relative log convergent cohomology.
We prove the coherence of relative log convergent cohomology in certain case by
using the comparison theorem between relative log convergent cohomlogy and
relative log crystalline cohomology, and we relates relative log convergent
cohomology to relative rigid cohomology to show the validity of Berthelot's
conjecture on the coherence and the overconvergence of relative rigid
cohomology for proper smooth families when they admit nice proper log smooth
compactification to which the coefficient extends logarithmically.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 06:47:31 GMT"
},
{
"version": "v2",
"created": "Wed, 21 May 2008 08:23:02 GMT"
}
] | 2008-05-21T00:00:00 | [
[
"Shiho",
"Atsushi",
""
]
] |
0707.1743 | Atsushi Shiho | Atsushi Shiho | Relative log convergent cohomology and relative rigid cohomology II | 80 pages, minor errors and typos fixed | null | null | null | math.NT math.AG | null | In this paper, we develop the theory of relative log convergent cohomology of
radius $\lambda$ ($0 < \lambda \leq 1$), which is a generalization of the
notion of relative log convergent cohomology in the previous paper. By
comparing this cohomology with relative log crystalline cohomology, relative
rigid cohomology and its variants and by using some technique of hypercovering,
we prove a version of Berthelot's conjecture on the overconvergence of relative
rigid cohomology for proper smooth families.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 07:08:19 GMT"
},
{
"version": "v2",
"created": "Wed, 21 May 2008 08:41:56 GMT"
}
] | 2008-05-21T00:00:00 | [
[
"Shiho",
"Atsushi",
""
]
] |
0707.1744 | Yusuke Ide | Yusuke Ide, Norio Konno, and Naoki Masuda | Statistical properties of a generalized threshold network model | 12 pages | Methodology and Computing in Applied Probability, Vol. 12, No. 3,
pp.361-377 (2010) | null | null | math.PR | null | The threshold network model is a type of finite random graphs. In this paper,
we introduce a generalized threshold network model. A pair of vertices with
random weights is connected by an edge when real-valued functions of the pair
of weights belong to given Borel sets. We extend several known limit theorems
for the number of prescribed subgraphs to show that the strong law of large
numbers can be uniform convergence. We also prove two limit theorems for the
local and global clustering coefficients.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 08:09:42 GMT"
}
] | 2010-10-12T00:00:00 | [
[
"Ide",
"Yusuke",
""
],
[
"Konno",
"Norio",
""
],
[
"Masuda",
"Naoki",
""
]
] |
0707.1745 | Lazhar Dhaouadi | Lazhar Dhaouadi, Ahmed Fitouhi | On the Graf's addition theorem for Hahn Exton q-Bessel function | null | null | null | null | math.CA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper we study the positivity of the generalized $q$-translation
associated with the $q$-Bessel Hahn Exton function which is deduced by a new
formulation of the Graf's addition formula related to this function.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 07:56:10 GMT"
},
{
"version": "v2",
"created": "Tue, 16 Sep 2008 18:55:07 GMT"
}
] | 2008-09-16T00:00:00 | [
[
"Dhaouadi",
"Lazhar",
""
],
[
"Fitouhi",
"Ahmed",
""
]
] |
0707.1746 | Dimitri Petritis | Mikhail Menshikov, Dimitri Petritis, Stanislav Volkov | Random environment on coloured trees | Published in at http://dx.doi.org/10.3150/07-BEJ101 the Bernoulli
(http://isi.cbs.nl/bernoulli/) by the International Statistical
Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm) | Bernoulli 2007, Vol. 13, No. 4, 966-980 | 10.3150/07-BEJ101 | IMS-BEJ-BEJ101 | math.PR | null | In this paper, we study a regular rooted coloured tree with random labels
assigned to its edges, where the distribution of the label assigned to an edge
depends on the colours of its endpoints. We obtain some new results relevant to
this model and also show how our model generalizes many other probabilistic
models, including random walk in random environment on trees, recursive
distributional equations and multi-type branching random walk on $\mathbb{R}$.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 07:58:40 GMT"
},
{
"version": "v2",
"created": "Wed, 28 Nov 2007 14:26:30 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Menshikov",
"Mikhail",
""
],
[
"Petritis",
"Dimitri",
""
],
[
"Volkov",
"Stanislav",
""
]
] |
0707.1747 | Shigehiro Yasui | Su Houng Lee, Shigehiro Yasui, Wei Liu and Che Ming Ko | Charmed Exotics in Heavy Ion Collisions | null | Eur.Phys.J.C54:259-265,2008 | 10.1140/epjc/s10052-007-0516-z | null | hep-ph | null | Based on the color-spin interaction in diquarks, we argue that charmed
multiquark hadrons are likely to exist. Because of the appreciable number of
charm quarks produced in central nucleus-nucleus collisions at
ultrarelativistic energies, production of charmed multiquark hadrons is
expected to be enhanced in these collisions. Using both the quark coalescence
model and the statistical hadronization model, we estimate the yield of charmed
tetraquark meson $T_{cc}$ and pentaquark baryon $\Theta_{cs}$ in heavy ion
collisions at RHIC and LHC. We further discuss the decay modes of these charmed
exotic hadrons in order to facilitate their detections in experiments.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 08:01:12 GMT"
},
{
"version": "v2",
"created": "Thu, 20 Sep 2007 13:12:04 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lee",
"Su Houng",
""
],
[
"Yasui",
"Shigehiro",
""
],
[
"Liu",
"Wei",
""
],
[
"Ko",
"Che Ming",
""
]
] |
0707.1748 | Cailotto Maurizio | Maurizio Cailotto, Luisa Fiorot | Algebraic Connections vs. Algebraic {$\cD$}-modules: inverse and direct
images | 11 pages | null | null | null | math.AG | null | In the dictionary between the language of (algebraic integrable) connections
and that of (algebraic) $\cD$-modules, to compare the definitions of inverse
images for connections and $\cD$-modules is easy. But the comparison between
direct images for connections (the classical construction of the Gauss-Manin
connection for smooth morphisms) and for $\cD$-modules, although known to
specialists, has been explicitly proved only recently in a paper of Dimca,
Maaref, Sabbah and Saito in 2000, where the authors' main technical tool was M.
Saito's equivalence between the derived category of $\cD$-modules and a
localized category of differential complexes. The aim of this short paper is to
give a simplified summary of the [DMSS] argument, and to propose an alternative
proof of this comparison which is simpler, in the sense that it does not use
Saito equivalence. Moreover, our alternative strategy of comparison works in a
context which is a precursor to the Gauss-Manin connection (at the level of
$f^{-1}\cD_Y$-modules, for a morphism $f:X\to Y$), and may be of some intrinsic
interest.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 08:09:40 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Cailotto",
"Maurizio",
""
],
[
"Fiorot",
"Luisa",
""
]
] |
0707.1749 | Christoph Schwanda | G. Leder (for the Belle collaboration) | New results from the B factories Belle and BaBar | 6 pages, 6 figures, submitted to the proceedings of the HCP06
conference, Duke University, NC, USA (May 22-26, 2006) | null | null | null | hep-ex | null | The BELLE detector has already accumulated e^+ e^- collision data at the
KEKB-collider corresponding to 600 fb^-1. BaBar has accumulated data of
approximately 390 fb^-1 at PEP-II. Both are running on asymmetric energy e^+
e^- colliders at the Upsilon(4S) energy. The paper selects important results
from both experiments with the emphasis on CP violation in B meson decays and
its implications for the Unitarity Triangle.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 08:33:25 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Leder",
"G.",
"",
"for the Belle collaboration"
]
] |
0707.1750 | Jan {\O}ystein Haavig Bakke | Jan {\O}ystein Haavig Bakke, Alex Hansen | The accuracy of roughness exponent measurement methods | null | null | null | null | cond-mat.stat-mech cond-mat.mtrl-sci | null | We test methods for measuring and characterizing rough profiles with emphasis
on measurements of the self-affine roughness exponent, and describes a simple
test to separate between roughness exponents originating from long range
correlations in the sign signs of the profile, and roughness exponents
originating from L{\'e}vy distributions of jumps. Based on tests on profiles
with known roughness exponents we find that the power spectrum density analysis
and the averaged wavelet coefficients method give the best estimates for
roughness exponents in the range 0.1 to 0.9. The error-bars are found to be
less than 0.03 for profile lengths larger than 256, and there are no systematic
bias in the estimates. We present quantitative estimates of the error-bars and
the systematic error and their dependence on the value of the roughness
exponent and the profile length. We also quantify how power-law noise can
modify the measured roughness exponent for measurement methods different from
the power spectrum density analysis and the second order correlation function
method.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 08:46:59 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Bakke",
"Jan Øystein Haavig",
""
],
[
"Hansen",
"Alex",
""
]
] |
0707.1751 | Qijin Chen | Yan He, Chih-Chun Chien, Qijin Chen, and K. Levin | Thermodynamics and superfluid density in BCS-BEC crossover with and
without population imbalance | 19 pages, 14 figures. Submitted to PRB | Phys. Rev. B. 76, 224516 (2007) | 10.1103/PhysRevB.76.224516 | null | cond-mat.str-el cond-mat.quant-gas cond-mat.supr-con | null | We address the thermodynamics, density profiles and superfluid density of
trapped fermions undergoing BCS-BEC crossover, with and without population
imbalance. Our approach represents a fully consistent treatment of "pseudogap
effects", which reflect the distinction between the pair formation temperature
$T^*$ and the pair condensation temperature $T_c$ and must be accommodated by
modifying the fermionic excitation spectrum. This distinction has been omitted
from all other many body approaches in the literature. We show how enforcing
this corollary implies that pairing fluctuation contributions enter into both
the gap and the number equations; this is necessary in order to be consistent
with a generalized Ward identity. Furthermore, we demonstrate that we obtain
physical results for the superfluid density $n_s(T)$ at all $T$. In contrast,
previous work in the literature has led to ill-behaved $n_s(T)$. The superfluid
density is a critical measure of the physicality of a given crossover theory.
In order to properly address thermodynamic properties of a trapped Fermi gas,
it is necessary to demonstrate that the particle density profiles are
consistent with experiment. The lack of demonstrable consistency between
theoretical and experimental density profiles, along with problematic behavior
found for $n_s(T)$, casts doubt on previous claims in the literature concerning
quantitative agreement between thermodynamical calculations and experiment.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 10:08:14 GMT"
}
] | 2011-09-13T00:00:00 | [
[
"He",
"Yan",
""
],
[
"Chien",
"Chih-Chun",
""
],
[
"Chen",
"Qijin",
""
],
[
"Levin",
"K.",
""
]
] |
0707.1752 | Astrid Veronig | B. Vrsnak, A.M. Veronig, J.K. Thalmann, T. Zic | Large amplitude oscillatory motion along a solar filament | Astron. Astrophys., 2007, in press | null | 10.1051/0004-6361:20077668 | null | astro-ph | null | Large amplitude oscillations of solar filaments is a phenomenon known for
more than half a century. Recently, a new mode of oscillations, characterized
by periodical plasma motions along the filament axis, was discovered. We
analyze such an event, recorded on 23 January 2002 in Big Bear Solar
Observatory H$\alpha$ filtergrams, in order to infer the triggering mechanism
and the nature of the restoring force. Motion along the filament axis of a
distinct buldge-like feature was traced, to quantify the kinematics of the
oscillatory motion. The data were fitted by a damped sine function, to estimate
the basic parameters of the oscillations. In order to identify the triggering
mechanism, morphological changes in the vicinity of the filament were analyzed.
The observed oscillations of the plasma along the filament was characterized by
an initial displacement of 24 Mm, initial velocity amplitude of 51 km/s, period
of 50 min, and damping time of 115 min. We interpret the trigger in terms of
poloidal magnetic flux injection by magnetic reconnection at one of the
filament legs. The restoring force is caused by the magnetic pressure gradient
along the filament axis. The period of oscillations, derived from the
linearized equation of motion (harmonic oscillator) can be expressed as
$P=\pi\sqrt{2}L/v_{A\phi}\approx4.4L/v_{A\phi}$, where $v_{A\phi}
=B_{\phi0}/\sqrt{\mu_0\rho}$ represents the Alfv\'en speed based on the
equilibrium poloidal field $B_{\phi0}$. Combination of our measurements with
some previous observations of the same kind of oscillations shows a good
agreement with the proposed interpretation.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 08:55:58 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Vrsnak",
"B.",
""
],
[
"Veronig",
"A. M.",
""
],
[
"Thalmann",
"J. K.",
""
],
[
"Zic",
"T.",
""
]
] |
0707.1753 | Kentaro Wada | Kentaro Wada | On decomposition numbers with Jantzen filtration of cyclotomic $q$-Schur
algebras | 20 pages | null | null | null | math.RT math.QA | null | Let $\Sc(\vL)$ be the cyclotomic $q$-Schur algebra associated to the
Ariki-Koike algebra $\He_{n,r}$, introduced by Dipper-James-Mathas. In this
paper, we consider $v$-decomposition numbers of $\Sc(\vL)$, namely
decomposition numbers with respect to the Jantzen filtrations of Weyl modules.
We prove, as a $v$-analogue of the result obtained by Shoji-Wada, a product
formula for $v$-decomposition numbers of $\Sc(\vL)$, which asserts that certain
$v$-decomposition numbers are expressed as a product of $v$-decomposition
numbers for various cyclotomic $q$-Schur algebras associated to Ariki-koike
algebras $\He_{n_i,r_i}$ of smaller rank. Moreover we prove a similar formula
for $v$-decomposition numbers of $\He_{n,r}$ by using a Schur functor.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 09:04:06 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Wada",
"Kentaro",
""
]
] |
0707.1754 | Beate Stelzer | Beate Stelzer (1), Alexander Scholz (2), Ray Jayawardhana (3) ((1)
INAF - OA Palermo, (2) SUPA St.Andrews, (3) Uni Toronto) | Emission Line Variability of the Accreting Young Brown Dwarf 2MASSW
J1207334-393254: From Hours to Years | accepted for publication in ApJ | null | 10.1086/521431 | null | astro-ph | null | We have obtained a series of high-resolution optical spectra for the brown
dwarf 2MASSW J1207334-393254 (2M1207) using the ESO Very Large Telescope with
the UVES spectrograph during two consecutive observing nights (time resolution
of ~12 min) and the Magellan Clay telescope with the MIKE spectrograph.
Combined with previously published results, these data allow us to investigate
changes in the emission line spectrum of 2M1207 on timescales of hours to
years. Most of the emission line profiles of 2M1207 are broad, in particular
that of Halpha, indicating that the dominant fraction of the emission must be
attributed to disk accretion rather than to magnetic activity. From the Halpha
10% width we deduce a relatively stable accretion rate between
10^(-10.1...-9.8) Msun/yr for two nights of consecutive observations.
Therefore, either the accretion stream is nearly homogeneous over (sub-)stellar
longitude or the system is seen face-on. Small but significant variations are
evident throughout our near-continuous observation, and they reach a maximum
after ~8 h, roughly the timescale on which maximum variability is expected
across the rotation cycle. Together with past measurements, we confirm that the
accretion rate of 2M1207 varies by more than one order of magnitude on
timescales of months to years. Such variable mass accretion yields a plausible
explanation for the observed spread in the accretion rate vs. mass diagram. The
magnetic field required to drive the funnel flow is on the order of a few
hundred G. Despite the obvious presence of a magnetic field, no radio nor X-ray
emission has been reported for 2M1207. Possibly strong accretion suppresses
magnetic activity in brown dwarfs, similar to the findings for higher mass T
Tauri stars.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 09:09:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Stelzer",
"Beate",
""
],
[
"Scholz",
"Alexander",
""
],
[
"Jayawardhana",
"Ray",
""
]
] |
0707.1755 | Christoph Janowitz | B. Ziegler, B. M\"uller, A. Krapf, H. Dwelk, C. Janowitz and R. Manzke | Coupling to a phononic mode in $Bi_{2-x}Pb_xSr_2CaCu_2O_{8+\delta}$:
Angle-resolved photoemission | null | PHYSICAL REVIEW B 77, 054520 (2008) | 10.1103/PhysRevB.77.054520 | null | cond-mat.supr-con | null | The kink in the dispersion and the drop in the width observed by
angle-resolved photoemission in the nodal direction of the Brillouin zone of
$\mathrm{Bi_{2-x}Pb_xSr_2CaCu_2O_{8+ \delta}}$ (abbreviated as (Pb)Bi2212) has
attracted broad interest [1-3]. Surprisingly optimally lead-doped (Pb)Bi2212
with $\mathrm{T_C>89K}$ as well as the shadow band were not investigated so
far, although the origin of the kink and the drop is still under strong debate.
In this context a resonant magnetic-mode scenario and an electron-phonon
coupling scenario are discussed controversially. Here we analyze the relevant
differences between both scenarios and conclude that the kink and the drop are
caused by a coupling of the electronic system to a phononic mode at least in
the nodal direction. It is found that besides the dispersion and the drop in
the width also the peak height as a new criterion can be used to define the
energy scale of the interaction, giving a new means for a precise and
consistent determination of the kink energy.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 09:27:02 GMT"
},
{
"version": "v2",
"created": "Fri, 2 Nov 2007 16:40:08 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Ziegler",
"B.",
""
],
[
"Müller",
"B.",
""
],
[
"Krapf",
"A.",
""
],
[
"Dwelk",
"H.",
""
],
[
"Janowitz",
"C.",
""
],
[
"Manzke",
"R.",
""
]
] |
0707.1756 | Aleksandar Ivic | Aleksandar Ivic | On the divisor function and the Riemann zeta-function in short intervals | 18 pages | Ramanujan J. 19(2009), 207-224 | null | null | math.NT | null | We obtain, for $T^\epsilon \le U=U(T)\le T^{1/2-\epsilon}$, asymptotic
formulas for $$ \int_T^{2T}(E(t+U) - E(t))^2 dt,\quad \int_T^{2T}(\Delta(t+U) -
\Delta(t))^2 dt, $$ where $\Delta(x)$ is the error term in the classical
divisor problem, and $E(T)$ is the error term in the mean square formula for
$|\zeta(1/2+it)|$. Upper bounds of the form $O_\epsilon(T^{1+\epsilon}U^2)$ for
the above integrals with biquadrates instead of square are shown to hold for
$T^{3/8} \le U =U(T) \ll T^{1/2}$. The connection between the moments of
$E(t+U) - E(t)$ and $|\zeta(1/2+it)|$ is also given. Generalizations to some
other number-theoretic error terms are discussed.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 09:33:59 GMT"
},
{
"version": "v2",
"created": "Mon, 17 Sep 2007 14:32:45 GMT"
},
{
"version": "v3",
"created": "Thu, 20 Sep 2007 09:10:14 GMT"
},
{
"version": "v4",
"created": "Fri, 26 Oct 2007 06:30:47 GMT"
},
{
"version": "v5",
"created": "Thu, 8 Nov 2007 08:55:24 GMT"
}
] | 2010-01-23T00:00:00 | [
[
"Ivic",
"Aleksandar",
""
]
] |
0707.1757 | Ken Matsuno | Ken Matsuno, Hideki Ishihara, Masashi Kimura and Shinya Tomizawa | Coalescence of Rotating Black Holes on Eguchi-Hanson Space | 20 pages, 9 figures | Phys.Rev.D76:104037,2007 | 10.1103/PhysRevD.76.104037 | OCU-PHYS 270, AP-GR 45 | hep-th gr-qc | null | We obtain new charged rotating multi-black hole solutions on the
Eguchi-Hanson space in the five-dimensional Einstein-Maxwell system with a
Chern-Simons term and a positive cosmological constant. In the two-black holes
case, these solutions describe the coalescence of two rotating black holes with
the spatial topologies of S^3 into a single rotating black hole with the
spatial topology of the lens space S^3/Z_2. We discuss the differences in the
horizon areas between our solutions and the two-centered Klemm-Sabra solutions
which describe the coalescence of two rotating black holes with the spatial
topologies of S^3 into a single rotating black hole with the spatial topology
of S^3.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 09:53:06 GMT"
}
] | 2008-11-27T00:00:00 | [
[
"Matsuno",
"Ken",
""
],
[
"Ishihara",
"Hideki",
""
],
[
"Kimura",
"Masashi",
""
],
[
"Tomizawa",
"Shinya",
""
]
] |
0707.1758 | Tim Lawson | S. Burgos (1), J. Forbes (1), C. Ghag (2), M. Gold (3), V. A.
Kudryavtsev (4), T. B. Lawson (4), D. Loomba (3), P. Majewski (4), J. E.
McMillan (4), D. Muna (4), A. StJ. Murphy (2), G. G. Nicklin (4), S. M.
Paling (4), A. Petkov (1), S. J. S. Plank (2), M. Robinson (4), N. Sanghi
(3), N. J. T. Smith (5), D. P. Snowden-Ifft (1), N. J. C. Spooner (4), T. J.
Sumner (6), J. Turk (3), T. Tziaferi (4) ((1) Occidental College LA USA, (2)
University of Edinburgh UK, (3) University of New Mexico USA, (4) University
of Sheffield UK, (5) Rutherford Appleton Laboratory UK, (6) Imperial College
London UK) | Track Reconstruction and Performance of DRIFT Directional Dark Matter
Detectors using Alpha Particles | 27 pages, 12 figures, 5 tables. Submitted to Nuclear Instruments and
Methods in Physics Research, Section A. Subj-class: Instrumentation and
Detectors | Nucl.Instrum.Meth.A584:114-128,2008 | 10.1016/j.nima.2007.10.013 | null | physics.ins-det | null | First results are presented from an analysis of data from the DRIFT-IIa and
DRIFT-IIb directional dark matter detectors at Boulby Mine in which alpha
particle tracks were reconstructed and used to characterise detector
performance--an important step towards optimising directional technology. The
drift velocity in DRIFT-IIa was [59.3 +/- 0.2 (stat) +/- 7.5 (sys)] m/s based
on an analysis of naturally-occurring alpha-emitting background. The drift
velocity in DRIFT-IIb was [57 +/- 1 (stat) +/- 3 (sys)] m/s determined by the
analysis of alpha particle tracks from a Po-210 source. 3D range reconstruction
and energy spectra were used to identify alpha particles from the decay of
Rn-222, Po-218, Rn-220 and Po-216. This study found that (22 +/- 2)% of Po-218
progeny (from Rn-222 decay) are produced with no net charge in 40 Torr CS2. For
Po-216 progeny (from Rn-220 decay) the uncharged fraction is (100 +0 -35)%.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 09:56:02 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Burgos",
"S.",
""
],
[
"Forbes",
"J.",
""
],
[
"Ghag",
"C.",
""
],
[
"Gold",
"M.",
""
],
[
"Kudryavtsev",
"V. A.",
""
],
[
"Lawson",
"T. B.",
""
],
[
"Loomba",
"D.",
""
],
[
"Majewski",
"P.",
""
],
[
"McMillan",
"J. E.",
""
],
[
"Muna",
"D.",
""
],
[
"Murphy",
"A. StJ.",
""
],
[
"Nicklin",
"G. G.",
""
],
[
"Paling",
"S. M.",
""
],
[
"Petkov",
"A.",
""
],
[
"Plank",
"S. J. S.",
""
],
[
"Robinson",
"M.",
""
],
[
"Sanghi",
"N.",
""
],
[
"Smith",
"N. J. T.",
""
],
[
"Snowden-Ifft",
"D. P.",
""
],
[
"Spooner",
"N. J. C.",
""
],
[
"Sumner",
"T. J.",
""
],
[
"Turk",
"J.",
""
],
[
"Tziaferi",
"T.",
""
]
] |
0707.1759 | Sergey Bastrukov | S. I. Bastrukov, H.-K. Chang, J. Takata, G.-T. Chen and I. V.
Molodtsova | Torsional shear oscillations in the neutron star crust driven by
restoring force of elastic stresses | 18 pages, 7 figures, MNRAS, accepted | null | 10.1111/j.1365-2966.2007.12414.x | null | astro-ph | null | We present several exact solutions of the eigenfrequency problem for
torsional shear vibrations in homogeneous and non-homogeneous models of the
neutron star crust governed by canonical equation of solid mechanics with a
restoring force of Hookean elasticity. Particular attention is given to regime
of large lengthscale nodeless axisymmetric differentially rotational
oscillations which are treated in spherical polar coordinates reflecting real
geometry of the neutron star crust. Highlighted is the distinction between
analytic forms and numerical estimates of the frequency, computed as a function
of multipole degree of nodeless torsional oscillations and fractional depth of
the crust, caused by different boundary conditions imposed on the toroidal
field of material displacements. The relevance of considered models to
quasiperiodic oscillations, recently detected during the flare of SGR 1806-20
and SGR 1900+14, is discussed.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 10:03:47 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 06:09:21 GMT"
},
{
"version": "v3",
"created": "Sat, 14 Jul 2007 03:54:53 GMT"
},
{
"version": "v4",
"created": "Wed, 25 Jul 2007 15:54:19 GMT"
},
{
"version": "v5",
"created": "Tue, 4 Sep 2007 14:30:37 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bastrukov",
"S. I.",
""
],
[
"Chang",
"H. -K.",
""
],
[
"Takata",
"J.",
""
],
[
"Chen",
"G. -T.",
""
],
[
"Molodtsova",
"I. V.",
""
]
] |
0707.1760 | Orr Shalit | Orr Shalit | E_0-dilation of strongly commuting CP_0-semigroups | 45 pages; a gap in section 6 has been filled; minimality proved | Journal of Functional Analysis, Vol. 255/1 46-89, 2008 | null | null | math.OA | null | We prove that every strongly commuting pair of CP_0-semigroups has a minimal
E_0-dilation. This is achieved in two major steps, interesting in themselves:
1: we show that a strongly commuting pair of CP_0-semigroups can be represented
via a two parameter product system representation; 2: we prove that every fully
coisometric product system representation has a fully coisometric, isometric
dilation. In particular, we obtain that every commuting pair of CP_0-semigroups
on B(H), H finite dimensional, has an E_0-dilation.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 10:20:32 GMT"
},
{
"version": "v2",
"created": "Sun, 9 Sep 2007 13:39:59 GMT"
}
] | 2008-06-04T00:00:00 | [
[
"Shalit",
"Orr",
""
]
] |
0707.1761 | Vladimir Shevelev | Vladimir Shevelev | On Excess of the Odious Primes | null | null | null | null | math.NT | null | We give a more strong heuristic justification of our conjecture on the excess
of the odious primes.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 10:21:13 GMT"
},
{
"version": "v2",
"created": "Fri, 12 Oct 2007 14:00:07 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Shevelev",
"Vladimir",
""
]
] |
0707.1762 | Jan Lorenz | Jan Lorenz | Continuous Opinion Dynamics under Bounded Confidence: A Survey | 22 pages, 3 figures, many references, minor corrections | International Journal of Modern Physics C Vol. 18, No. 12, 1819 -
1838 (2007) | 10.1142/S0129183107011789 | null | physics.soc-ph math.DS nlin.AO | null | Models of continuous opinion dynamics under bounded confidence have been
presented independently by Krause and Hegselmann and by Deffuant et al in 2000.
They have raised a fair amount of attention in the communities of social
simulation, sociophysics and complexity science. The researchers working on it
come from disciplines as physics, mathematics, computer science, social
psychology and philosophy.
Agents hold continuous opinions which they can gradually adjust if they hear
the opinions of others. The idea of bounded confidence is that agents only
interact if they are close in opinion to each other. Usually, the models are
analyzed with agent-based simulations in a Monte-Carlo style, but they can also
be reformulated on the agent's density in the opinion space in a
master-equation style. This paper is to present the agent-based and
density-based modeling frameworks including the cases of multidimensional
opinions and heterogeneous bounds of confidence; second, to give the
bifurcation diagrams of cluster configuration in the homogeneous model with
uniformly distributed initial opinions; third to review the several extensions
and the evolving phenomena which have been studied so far; and fourth to state
some basic open questions.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 10:37:16 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Jan 2008 14:17:13 GMT"
}
] | 2008-03-06T00:00:00 | [
[
"Lorenz",
"Jan",
""
]
] |
0707.1763 | B. C. Sanctuary | B. C. Sanctuary | The two dimensional spin and its resonance fringe | 15 pages, 8 figures, 1 Table. Shortened paper by 10 pages | null | null | null | physics.gen-ph | null | Violation of Bell's Inequalities gives experimental evidence for the
existence of a spin 1/2 which has two simultaneous axes of spin quantization
rather than one. These couple to form a resonance state, called the spin
fringe, and this quantum effect is solely responsible for violation of Bell's
Inequalities within this model. The Bell states can be represented by products
of these spin states and leads to the intuitive concept that as entangled
states decompose they form biparticles that are not entangled. In EPR
coincidence experiments filter settings for both the Bell and CHSH forms of
Bell's Inequalities are rationalized in terms of the correlation between
biparticles.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 10:56:38 GMT"
},
{
"version": "v2",
"created": "Wed, 10 Oct 2007 02:36:24 GMT"
}
] | 2007-10-10T00:00:00 | [
[
"Sanctuary",
"B. C.",
""
]
] |
0707.1764 | Boris Ermolaev | B.I. Ermolaev, M. Greco, S.I. Troyan | Spin structure function g_1 at small x and arbitrary $Q^2: Total
resummaion of leading logarithms vs Standard Approach | Talk given at XV International Workshop on Deep-Inelastic Scattering
and Related Subjects, 16-20 April 2007 Munich, Germany | null | null | null | hep-ph | null | The Standard Approach (SA) for description of the structure function g_1
combines the DGLAP evolution equations and Standard Fits for the initial parton
densities. The DGLAP equations describe the region of large Q^2 and large x, so
there are not theoretical grounds to exploit them at small x. In practice,
extrapolation of DGLAP into the region of large Q^2 and small x is done with
complementing DGLAP with special, singular (~x^{-a}) phenomenological fits for
the initial parton densities. The factors x^{-a} are wrongly believed to be of
the non-perturbative origin. Actually, they mimic the resummation of logs of x
and should be expelled from the fits when the resummation is accounted for.
Contrary to SA, the resummaton of logarithms of x is a straightforward and
natural way to describe g_1 in the small-x region. This approach can be used at
both large and small Q^2 where DGLAP cannot be used by definition. Confronting
this approach and SA demonstrates that the singular initial parton densities
and the power Q^2-corrections (or at least a sizable part of them) are rather
not real physical phenomena but the artefacts caused by extrapolating DGLAP
into the small-x region.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:07:20 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Ermolaev",
"B. I.",
""
],
[
"Greco",
"M.",
""
],
[
"Troyan",
"S. I.",
""
]
] |
0707.1765 | Jos\'e M. Tornero | I. Garcia-Selfa, Jose M. Tornero | On the discriminant of elliptic curves with non-trivial torsion | Temporarily withdrawn | null | null | null | math.NT | null | For those elliptic curves defined over the rational with non--trivial torsion
subgroup, we find a tight relationship between the torsion subgroup itself and
a Galois group naturally arising from the curve.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:19:53 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Jul 2007 11:45:29 GMT"
}
] | 2007-07-19T00:00:00 | [
[
"Garcia-Selfa",
"I.",
""
],
[
"Tornero",
"Jose M.",
""
]
] |
0707.1766 | D. V. Osipov | D. V. Osipov, A. N. Parshin | Harmonic analysis on local fields and adelic spaces I | 69 pages; corrected typos and inserted some changes into the last
section | Izvestiya: Mathematics, 2008, 72:5, pp. 915-976 | 10.1070/IM2008v072n05ABEH002424 | null | math.AG math.NT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We develop a harmonic analysis on objects of some category $C_2$ of
infinite-dimensional filtered vector spaces over a finite field. It includes
two-dimensional local fields and adelic spaces of algebraic surfaces defined
over a finite field. The main result is the theory of the Fourier transform on
these objects and two-dimensional Poisson formulas.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 14:30:51 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Dec 2007 13:35:51 GMT"
},
{
"version": "v3",
"created": "Mon, 17 Nov 2008 15:13:11 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Osipov",
"D. V.",
""
],
[
"Parshin",
"A. N.",
""
]
] |
0707.1767 | Ian McIntosh | Ian McIntosh, Pascal Romon | The spectral data for Hamiltonian stationary Lagrangian tori in R^4 | 30 pages. Version 3: a complete rewrite of version 2 with new results
and two significant corrections | Differ.Geom.Appl.29:125-146,2011 | 10.1016/j.difgeo.2011.02.007 | null | math.DG math.SG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This article determines the spectral data, in the integrable systems sense,
for all weakly conformally immersed Hamiltonian stationary Lagrangian in
$\R^4$. This enables us to describe their moduli space and the locus of branch
points of such an immersion. This is also an informative example in integrable
systems geometry, since the group of ambient isometries acts non-trivially on
the spectral data and the relevant energy functional (the area) need not be
constant under deformations by higher flows.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:21:36 GMT"
},
{
"version": "v2",
"created": "Mon, 6 Oct 2008 10:49:59 GMT"
},
{
"version": "v3",
"created": "Mon, 7 Dec 2009 09:35:59 GMT"
}
] | 2011-03-15T00:00:00 | [
[
"McIntosh",
"Ian",
""
],
[
"Romon",
"Pascal",
""
]
] |
0707.1768 | Orestis Efthimiou | S. Creek, O. Efthimiou, P. Kanti, K. Tamvakis | Greybody factors in a rotating black-hole background-II : fermions and
gauge bosons | 22 pages, 8 figures, added references | Phys.Rev.D76:104013,2007 | 10.1103/PhysRevD.76.104013 | null | hep-th hep-ph | null | We study the emission of fermion and gauge boson degrees of freedom on the
brane by a rotating higher-dimensional black hole. Using matching techniques,
for the near-horizon and far-field regime solutions, we solve analytically the
corresponding field equations of motion. From this, we derive analytical
results for the absorption probabilities and Hawking radiation emission rates,
in the low-energy and low-rotation case, for both species of fields. We produce
plots of these, comparing them to existing exact numerical results with very
good agreement. We also study the total absorption cross-section and
demonstrate that, as in the non-rotating case, it has a different behaviour for
fermions and gauge bosons in the low-energy limit, while it follows a universal
behaviour -- reaching a constant, spin-independent, asymptotic value -- in the
high-energy regime.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:24:35 GMT"
},
{
"version": "v2",
"created": "Fri, 5 Oct 2007 14:18:21 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Creek",
"S.",
""
],
[
"Efthimiou",
"O.",
""
],
[
"Kanti",
"P.",
""
],
[
"Tamvakis",
"K.",
""
]
] |
0707.1769 | MIchal Marchewka | M. Marchewka, E. M. Sheregii, I. Tralle, D. Ploch, G. Tomaka, M.
Furdak, A. Kolek, A. Stadler, K. Mleczko, D. Zak, W. Strupinski, A. Jasik, R.
Jakiela | Magnetospectroscopy of symmetric and anti-symmetric states in double
quantum wells | 20 pages, 20 figures | null | 10.1016/j.physe.2007.11.020 | null | cond-mat.str-el | null | The experimental results obtained for the magneto-transport in the
InGaAs/InAlAs double quantum wells (DQW) structures of two different shapes of
wells are reported. The beating-effect occurred in the Shubnikov-de Haas (SdH)
oscillations was observed for both types of the structures at low temperatures
in the parallel transport when magnetic field was perpendicular to the layers.
An approach to the calculation of the Landau levels energies for DQW structures
was developed and then applied to the analysis and interpretation of the
experimental data related to the beating-effect. We also argue that in order to
account for the observed magneto-transport phenomena (SdH and Integer Quantum
Hall effect), one should introduce two different quasi-Fermi levels
characterizing two electron sub-systems regarding symmetry properties of their
states, symmetric and anti-symmetric ones which are not mixed by
electron-electron interaction.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:29:26 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Marchewka",
"M.",
""
],
[
"Sheregii",
"E. M.",
""
],
[
"Tralle",
"I.",
""
],
[
"Ploch",
"D.",
""
],
[
"Tomaka",
"G.",
""
],
[
"Furdak",
"M.",
""
],
[
"Kolek",
"A.",
""
],
[
"Stadler",
"A.",
""
],
[
"Mleczko",
"K.",
""
],
[
"Zak",
"D.",
""
],
[
"Strupinski",
"W.",
""
],
[
"Jasik",
"A.",
""
],
[
"Jakiela",
"R.",
""
]
] |
0707.1770 | Martin Hohenadler | Martin Hohenadler and Peter B Littlewood | Quantum Monte Carlo results for bipolaron stability in quantum dots | 5 pages, 2 figures, final version to appear in Phys. Rev. B | Phys. Rev. B 76, 155122 (2007) | 10.1103/PhysRevB.76.155122 | null | cond-mat.str-el cond-mat.mtrl-sci | null | Bipolaron formation in a two-dimensional lattice with harmonic confinement,
representing a simplified model for a quantum dot, is investigated by means of
quantum Monte Carlo simulations. This method treats all interactions exactly
and takes into account quantum lattice fluctuations. Calculations of the
bipolaron binding energy reveal that confinement opposes bipolaron formation
for weak electron-phonon coupling, but abets a bound state at intermediate to
strong coupling. Tuning the system from weak to strong confinement gives rise
to a small reduction of the minimum Frohlich coupling parameter for the
existence of a bound state.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:31:55 GMT"
},
{
"version": "v2",
"created": "Mon, 1 Oct 2007 10:48:51 GMT"
}
] | 2007-10-25T00:00:00 | [
[
"Hohenadler",
"Martin",
""
],
[
"Littlewood",
"Peter B",
""
]
] |
0707.1771 | Elaine Crooks | E.C.M. Crooks, E.N. Dancer and D. Hilhorst | On long-time dynamics for competition-diffusion systems with
inhomogeneous Dirichlet boundary conditions | To appear in Topological Methods in Nonlinear Analysis | null | null | null | math.AP | null | We consider a two-component competition-diffusion system with equal diffusion
coefficients and inhomogeneous Dirichlet boundary conditions. When the
interspecific competition parameter tends to infinity, the system solution
converges to that of a freeboundary problem. If all stationary solutions of
this limit problem are non-degenerate and if a certain linear combination of
the boundary data does not identically vanish, then for sufficiently large
interspecific competition, all non-negative solutions of the
competition-diffusion system converge to stationary states as time tends to
infinity. Such dynamics are much simpler than those found for the corresponding
system with either homogeneous Neumann or homogeneous Dirichlet boundary
conditions.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:35:55 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Crooks",
"E. C. M.",
""
],
[
"Dancer",
"E. N.",
""
],
[
"Hilhorst",
"D.",
""
]
] |
0707.1772 | Edward Crane | Edward Crane | A note on the Hayman-Wu theorem | 9 pages, 1 postscript figure. Invited submission to Computational
Methods and Function Theory, special issue in honour of Walter Hayman | null | null | null | math.CV | null | The Hayman-Wu theorem states that the preimage of a line or circle L under a
conformal mapping from the unit disc to a simply-connected domain U has total
Euclidean length bounded by an absolute constant. The best possible constant is
known to lie in the interval [pi^2, 4 pi), thanks to work of {\O}yma and Rohde.
Earlier, Brown Flinn showed that the total length is at most pi^2 in the
special case in which U contains L. Let r be the anti-M\"obius map that fixes L
pointwise. In this note we extend the sharp bound pi^2 to the case where each
connected component of the intersection of U with r(U) is bounded by one arc of
U and its image under r. We also strengthen the bounds slightly by replacing
Euclidean length with the strictly larger spherical length restricted to the
unit disc.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:39:37 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Crane",
"Edward",
""
]
] |
0707.1773 | Yehuda Schlesinger | A. V. Butenko, V. Sandomirsky, R. Kahatabi, Y. Schlesinger, Z.
Dashevsky and V. Kasiyan | Pyroelectric Effect Induced by the Built-in Field in the p-n Junction of
the Quantum Paraelectric PbTe: Experimental Study | null | null | null | null | cond-mat.other | null | We report here the first observation of a pyroelectric effect in a non-polar
semiconductor. This effect originates in the temperature dependent electric
dipole of the p-n junction. The junction was illuminated by a chopped CO2 laser
beam, and periodic and single-pulse pyroelectric signals were observed and
measured as a function of temperature, reverse bias voltage and chopper
frequency. The measured pyroelectric coefficient is about 10^(-3) microC/cm2K
in the region of 40-80 K. The theoretical model describes quantitatively all
experimental features. The time evolution of the temperature inside the
junction region was reconstructed.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:54:23 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Butenko",
"A. V.",
""
],
[
"Sandomirsky",
"V.",
""
],
[
"Kahatabi",
"R.",
""
],
[
"Schlesinger",
"Y.",
""
],
[
"Dashevsky",
"Z.",
""
],
[
"Kasiyan",
"V.",
""
]
] |
0707.1774 | Baruch Solel | Paul S. Muhly and Baruch Solel | The Poisson Kernel for Hardy Algebras | null | null | null | null | math.OA | null | This note contributes to a circle of ideas that we have been developing
recently in which we view certain abstract operator algebras $H^{\infty}(E)$,
which we call Hardy algebras, and which are noncommutative generalizations of
classical $H^{\infty}$, as spaces of functions defined on their spaces of
representations. We define a generalization of the Poisson kernel, which
``reproduces'' the values, on $\mathbb{D}((E^{\sigma})^*)$, of the
``functions'' coming from $H^{\infty}(E)$. We present results that are natural
generalizations of the Poisson integral formuala. They also are easily seen to
be generalizations of formulas that Popescu developed. We relate our Poisson
kernel to the idea of a characteristic operator function and show how the
Poisson kernel identifies the ``model space'' for the canonical model that can
be attached to a point in the disc $\mathbb{D}((E^{\sigma})^*)$. We also
connect our Poission kernel to various "point evaluations" and to the idea of
curvature.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:42:28 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Muhly",
"Paul S.",
""
],
[
"Solel",
"Baruch",
""
]
] |
0707.1775 | Hua-Shu Dou | Hua-Shu Dou | On the Rayleigh theorem for inflectional velocity instability of
inviscid flows | 9 pages; 5 pictures. Presented as: Hua-Shu Dou, Patterns generated
during the transition to turbulence, IMS Workshop on BRAIDS, NUS, Singapore,
June 18-22, 2007
http://www.ims.nus.edu.sg/Programs/braids/abstracts.htm#hsdou | null | null | null | physics.flu-dyn physics.class-ph physics.geo-ph | null | It is exactly proved that the classical Rayleigh Theorem on inflectional
velocity instability is wrong which states that the necessary condition for
instability of inviscid flow is the existence of an inflection point on the
velocity profile. It is shown that the disturbance amplified in 2D inviscid
flows is necessarily 3D. After the break down of T-S wave in 2D parallel flows,
the disturbance becomes a type of spiral waves which proceed along the
streamwise direction. This is just the origin of formation of streamwise
vortices.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 11:58:43 GMT"
},
{
"version": "v2",
"created": "Fri, 3 Aug 2007 07:02:39 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Dou",
"Hua-Shu",
""
]
] |
0707.1776 | Sezgin Ayg\"un | M. Aygun, S. Aygun, I. Yilmaz, H. Baysal, I. Tarhan | M{\o}ller Energy-Momentum Complex in General Relativity for Higher
Dimensional Universes | This submission has been withdrawn by arXiv administrators due to
inappropriate text reuse from external sources | Chin.Phys.Lett.24:1821-1824,2007 | 10.1088/0256-307X/24/7/010 | null | gr-qc | null | This submission has been withdrawn by arXiv administrators due to
inappropriate text reuse from external sources
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 12:03:45 GMT"
},
{
"version": "v2",
"created": "Wed, 22 Aug 2007 19:07:32 GMT"
}
] | 2022-04-22T00:00:00 | [
[
"Aygun",
"M.",
""
],
[
"Aygun",
"S.",
""
],
[
"Yilmaz",
"I.",
""
],
[
"Baysal",
"H.",
""
],
[
"Tarhan",
"I.",
""
]
] |
0707.1777 | Douglas Galvao | Karla S. Troche, Vitor R. Coluci, Douglas S. Galvao | Atomistic Study of the Encapsulation of Diamondoids Inside Carbon
Nanotubes | 11 Pages, 6 Figures | null | null | null | cond-mat.mtrl-sci | null | The encapsulation of hydrogen-terminated nanosized diamond fragments (the
so-called diamondoids) into armchair single walled carbon nanotubes with
diameters in the range of 1.0 up to 2.2 nm has been investigated using
classical molecular dynamics simulations. Diameter dependent molecular ordered
phases were found for the encapsulation of adamantane (C10H16), diamantane
(C14H20), and dihydroxy diamantane (C14H20O2). The same types of chiral ordered
phases (double, triple, 4- and 5-stranded helices) observed for the
encapsulation of C60 molecules were also observed for diamondoids. On the other
hand, some achiral phases comprising layered structures were not observed. Our
results also indicate that the modification of diamantane through
functionalization with hydroxyl groups can lead to an enhancement of the
packing of molecules inside the nanotubes compared to nonfunctionalized
compounds. Comparisons to hard-sphere models are also presented revealing
differences, specially when more asymmetrical diamondoids are considered. For
larger structures (adamantane tetramers) we have not observed long-range
ordering for nanotubes with diameters in the range of 1.49 to 2.17 nm but only
a tendency to form incomplete helical structures.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 12:07:22 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Troche",
"Karla S.",
""
],
[
"Coluci",
"Vitor R.",
""
],
[
"Galvao",
"Douglas S.",
""
]
] |
0707.1778 | Joseph Lazio | T. J. W. Lazio (1), R. Ojha (2,3), A. L. Fey (3), L. Kedziora-Chudczer
(4), J. M. Cordes (5), D. L. Jauncey (6), J. E. J. Lovell (6) ((1) NRL; (2)
NVI; (3) USNO; (4) U. Sydney; (5) Cornell University and NAIC; (6) ATNF) | Angular Broadening of Intraday Variable AGN. II. Interstellar and
Intergalactic Scattering | 13 pages, 4 figures; AASTeX format; ApJ in press | null | 10.1086/520572 | NRL/JA/7210-07-0038 | astro-ph | null | We analyze a sample of 58 multi-wavelength, Very Long Baseline Array
observations of active galactic nuclei (AGN) to determine their scattering
properties. Approximately 75% of the sample consists of AGN that exhibit
centimeter-wavelength intraday variability (interstellar scintillation) while
the other 25% do not show intraday variability. We find that interstellar
scattering is measurable for most of these AGN, and the typical broadening
diameter is 2 mas at 1 GHz. We find that the scintillating AGN are typically at
lower Galactic latitudes than the non-scintillating AGN, consistent with the
scenario that intraday variability is a propagation effect from the Galactic
interstellar medium. The magnitude of the inferred interstellar broadening
measured toward the scintillating AGN, when scaled to higher frequencies, is
comparable to the diameters inferred from analyses of the light curves for the
more well-known intraday variable sources. However, we find no difference in
the amount of scattering measured toward the scintillating versus
non-scintillating AGN. A consistent picture is one in which the scintillation
results from localized regions ("clumps") distributed throughout the Galactic
disk, but which individually make little contribution to the angular
broadening. Of the 58 AGN observed, 37 (64%) have measured redshifts. At best,
a marginal trend is found for scintillating (non-scintillating) AGN to have
smaller (larger) angular diameters at higher redshifts. We also use our
observations to try to constrain the possibility of intergalactic scattering.
While broadly consistent with the scenario of a highly turbulent intergalactic
medium, our observations do not place significant constraints on its
properties.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 17:47:01 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lazio",
"T. J. W.",
""
],
[
"Ojha",
"R.",
""
],
[
"Fey",
"A. L.",
""
],
[
"Kedziora-Chudczer",
"L.",
""
],
[
"Cordes",
"J. M.",
""
],
[
"Jauncey",
"D. L.",
""
],
[
"Lovell",
"J. E. J.",
""
]
] |
0707.1779 | Tsutomu Kambe | Tsutomu Kambe | Variational formulation of the motion of an ideal fluid on the basis of
gauge principle | 5 pages. Accepted (5 Sept 2007) to Proc of EE250 (Physica D, 2008) | null | 10.1016/j.physd.2007.09.020 | null | nlin.CD | null | On the basis of gauge principle in the field theory, a new variational
formulation is presented for flows of an ideal fluid. The fluid is defined
thermodynamically by mass density and entropy density, and its flow fields are
characterized by symmetries of translation and rotation. A structure of
rotation symmetry is equipped with a Lagrangian $\Lambda_A$ including
vorticity, in addition to Lagrangians of translation symmetry. From the action
principle, Euler's equation of motion is derived. In addition, the equations of
continuity and entropy are derived from the variations. Equations of conserved
currents are deduced as the Noether theorem in the space of Lagrangian
coordinate $\ba$. It is shown that, with the translation symmetry alone, there
is freedom in the transformation between the Lagrangian $\ba$-space and
Eulerian $\bx$-space. The Lagrangian $\Lambda_A$ provides non-trivial topology
of vorticity field and yields a source term of the helicity. The vorticity
equation is derived as an equation of the gauge field. Present formulation
provides a basis on which the transformation between the $\ba$ space and the
$\bx$ space is determined uniquely.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 12:17:20 GMT"
},
{
"version": "v2",
"created": "Tue, 7 Aug 2007 05:57:12 GMT"
},
{
"version": "v3",
"created": "Wed, 8 Aug 2007 00:54:13 GMT"
},
{
"version": "v4",
"created": "Mon, 10 Sep 2007 05:52:17 GMT"
},
{
"version": "v5",
"created": "Fri, 12 Oct 2007 02:26:45 GMT"
}
] | 2007-10-12T00:00:00 | [
[
"Kambe",
"Tsutomu",
""
]
] |
0707.1780 | Carlos Sab\'in | Carlos Sab\'in and Guillermo Garc\'ia-Alcaine | A classification of entanglement in three-qubit systems | Shortened version. Accepted in EPJD | Eur. Phys. J. D 48, 435-442 (2008) | 10.1140/epjd/e2008-00112-5 | null | quant-ph | null | We present a classification of three-qubit states based in their three-qubit
and reduced two-qubit entanglements. For pure states these criteria can be
easily implemented, and the different types can be related with sets of
equivalence classes under Local Unitary operations. For mixed states
characterization of full tripartite entanglement is not yet solved in general;
some partial results will be presented here.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 12:22:22 GMT"
},
{
"version": "v2",
"created": "Tue, 29 Jan 2008 16:24:39 GMT"
},
{
"version": "v3",
"created": "Tue, 1 Apr 2008 16:06:09 GMT"
},
{
"version": "v4",
"created": "Wed, 2 Apr 2008 07:54:59 GMT"
},
{
"version": "v5",
"created": "Mon, 19 May 2008 09:20:35 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sabín",
"Carlos",
""
],
[
"García-Alcaine",
"Guillermo",
""
]
] |
0707.1781 | David Krejcirik | David Krejcirik | Calculation of the metric in the Hilbert space of a PT-symmetric model
via the spectral theorem | LaTeX, 6 pages | J. Phys. A: Math. Theor. 41 (2008) 244012. | 10.1088/1751-8113/41/24/244012 | null | math-ph math.MP quant-ph | null | In a previous paper (arXiv:math-ph/0604055) we introduced a very simple
PT-symmetric non-Hermitian Hamiltonian with real spectrum and derived a closed
formula for the metric operator relating the problem to a Hermitian one. In
this note we propose an alternative formula for the metric operator, which we
believe is more elegant and whose construction -- based on a backward use of
the spectral theorem for self-adjoint operators -- provides new insights into
the nature of the model.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 12:31:35 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Krejcirik",
"David",
""
]
] |
0707.1782 | Jerome Petri | Jerome Petri, Yuri Lyubarsky | Magnetic reconnection at the termination shock in a striped pulsar wind | Accepted by A&A | Int.J.Mod.Phys.D17:1961-1967,2008 | 10.1142/S0218271808013637 | null | astro-ph | null | Most of the rotational luminosity of a pulsar is carried away by a
relativistic magnetised wind in which the matter energy flux is negligible
compared to the Poynting flux. Near the equatorial plane of an obliquely
rotating pulsar magnetosphere, the magnetic field reverses polarity with the
pulsar period, forming a wind with oppositely directed field lines. This
structure is called a striped wind; dissipation of alternating fields in the
striped wind is the object of our study.
The aim of this paper is to study the conditions required for magnetic energy
release at the termination shock of the striped pulsar wind. Magnetic
reconnection is considered via analytical methods and 1D relativistic PIC
simulations.
An analytical condition on the upstream parameters for partial and full
magnetic reconnection is derived from the conservation laws of energy, momentum
and particle number density across the relativistic shock. Furthermore, by
using a 1D relativistic PIC code, we study in detail the reconnection process
at the termination shock.
We found a very simple criterion for dissipation of alternating fields at the
termination shock, depending on the upstream parameters of the flow. 1D
relativistic PIC simulations are in agreement with our criterion.
Thus, alternating magnetic fields annihilate easily at relativistic highly
magnetised shocks.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 12:25:14 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Petri",
"Jerome",
""
],
[
"Lyubarsky",
"Yuri",
""
]
] |
0707.1783 | Marco Castellano | M. Castellano, S. Salimbeni, D. Trevese, A. Grazian, L. Pentericci, F.
Fiore, A. Fontana, E. Giallongo, P. Santini, S. Cristiani, M. Nonino and E.
Vanzella | A Photometrically Detected Forming Cluster of Galaxies at Redshift 1.6
in the GOODS Field | 6 pages, 5 figures (1 in color), uses emulateapj.cls Latex class
file, accepted for publication in ApJ | null | 10.1086/521595 | null | astro-ph | null | We report the discovery of a localized overdensity at z~1.6 in the
GOODS-South Field, presumably a poor cluster in the process of formation. The
three-dimensional galaxy density has been estimated on the basis of well
calibrated photometric redshifts from the multiband photometric GOODS-MUSIC
catalog using the (2+1)D technique. The density peak is embedded in the larger
scale overdensity of galaxies known to exist at z=1.61 in the area. The
properties of the member galaxies are compared to those of the surrounding
field and we found that the two populations are significantly different
supporting the reality of the structure. The reddest galaxies, once evolved
according to their best fit models, have colors consistent with the red
sequence of lower redshift clusters. The estimated M_200 total mass of the
cluster is in the range 1.3 x 10^14 - 5.7x 10^14 Msun, depending on the assumed
bias factor b. An upper limit for the 2-10 keV X-ray luminosity, based on the
1Ms Chandra observations, is L_X=0.5 x 10^43 erg s^-1, suggesting that the
cluster has not yet reached the virial equilibrium.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 12:55:46 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Castellano",
"M.",
""
],
[
"Salimbeni",
"S.",
""
],
[
"Trevese",
"D.",
""
],
[
"Grazian",
"A.",
""
],
[
"Pentericci",
"L.",
""
],
[
"Fiore",
"F.",
""
],
[
"Fontana",
"A.",
""
],
[
"Giallongo",
"E.",
""
],
[
"Santini",
"P.",
""
],
[
"Cristiani",
"S.",
""
],
[
"Nonino",
"M.",
""
],
[
"Vanzella",
"E.",
""
]
] |
0707.1784 | Gustav Kramer | G. Kramer | Recent developments in heavy flavour production | 12 pages, 10 figures, to appear in the proceedings of XV
International Workshop in Deep-Inelastic Scattering (DIS 2007), Munich,
Germany, April 16-20, 2007 | null | 10.1142/S0217751X08042043 | null | hep-ph | null | We review one-particle inclusive production of heavy-flavoured hadrons in a
framework which resums the large collinear logarithms through the evolution of
the FFs and PDFs and retains the full dependence on the heavy-quark mass
without additional theoretical assumptions. We focus on presenting results for
the inclusive cross section for the production of charmed mesons in p anti-p
collisions and the comparison with CDF data from the Tevatron as well as on
inclusive B-meson production and comparison with recent CDF data. The third
topic is the production of D^* mesons in photoproduction and comparison with
recent H1 data from HERA.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:12:07 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kramer",
"G.",
""
]
] |
0707.1785 | Laurent Thomann | Laurent Thomann | Instabilities for supercritical Schr\"odinger equations in analytic
manifolds | 31 pages | null | null | null | math.AP math-ph math.MP | null | In this paper we consider supercritical nonlinear Schr\"odinger equations in
an analytic Riemannian manifold $(M^d,g)$, where the metric $g$ is analytic.
Using an analytic WKB method, we are able to construct an Ansatz for the
semiclassical equation for times independent of the small parameter. These
approximate solutions will help to show two different types of instabilities.
The first is in the energy space, and the second is an immediate loss of
regularity in higher Sobolev norms.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:13:31 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Thomann",
"Laurent",
""
]
] |
0707.1786 | Svante Janson | Svante Janson, Malwina Luczak | A new approach to the giant component problem | 21 pages | null | null | null | math.CO math.PR | null | We study the largest component of a random (multi)graph on n vertices with a
given degree sequence. We let n tend to infinity. Then, under some regularity
conditions on the degree sequences, we give conditions on the asymptotic shape
of the degree sequence that imply that with high probability all the components
are small, and other conditions that imply that with high probability there is
a giant component and the sizes of its vertex and edge sets satisfy a law of
large numbers; under suitable assumptions these are the only two possibilities.
In particular, we recover the results by Molloy and Reed on the size of the
largest component in a random graph with a given degree sequence.
We further obtain a new sharp result for the giant component just above the
threshold, generalizing the case of G(n,p) with np=1+omega(n)n^{-1/3}, where
omega(n) tends to infinity arbitrarily slowly.
Our method is based on the properties of empirical distributions of
independent random variables, and leads to simple proofs.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 16:46:50 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Janson",
"Svante",
""
],
[
"Luczak",
"Malwina",
""
]
] |
0707.1787 | Simeon Zamkovoy | Simeon Zamkovoy | Canonical connections on paracontact manifolds | 24 pages | null | null | null | math.DG | null | The canonical paracontact connection is defined and it is shown that its
torsion is the obstruction the paracontact manifold to be paraSasakian. A
$\mathcal{D}$-homothetic transformation is determined as a special gauge
transformation. The $\eta$-Einstein manifold are defined, it is prove that
their scalar curvature is a constant and it is shown that in the paraSasakian
case these spaces can be obtained from Einstein paraSasakian manifolds with a
$\mathcal{D}$-homothetic transformations. It is shown that an almost
paracontact structure admits a connection with totally skew-symmetric torsion
if and only if the Nijenhuis tensor of the paracontact structure is
skew-symmetric and the defining vector field is Killing.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:36:06 GMT"
},
{
"version": "v2",
"created": "Fri, 24 Aug 2007 13:34:10 GMT"
}
] | 2007-08-24T00:00:00 | [
[
"Zamkovoy",
"Simeon",
""
]
] |
0707.1788 | Benjamin Lungwitz | Benjamin Lungwitz and Marcus Bleicher | Searching for the Critical Point of QCD: Theoretical Benchmark
Calculations | 10 pages, 10 figures | Phys.Rev.C76:044904,2007 | 10.1103/PhysRevC.76.044904 | null | nucl-th | null | We present a comprehensive study of event-by-event multiplicity fluctuations
in nucleon-nucleon and nucleus-nucleus interactions from AGS/FAIR to RHIC
energies within the UrQMD transport approach. The scaled variances of negative,
positive, and all charged hadrons are analysed. The scaled variance in central
Pb+Pb collisions increases with energy and behaves similar to inelastic p+p
interactions. We find a non-trivial dependence of multiplicity fluctuations on
the rapidity and transverse momentum interval used for the analysis and on the
centrality selection procedure. Quantitative predictions for the NA49
experiment are given, taking into account the acceptance of the detector and
the selection procedure of central events.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:26:00 GMT"
},
{
"version": "v2",
"created": "Fri, 20 Jul 2007 10:21:36 GMT"
},
{
"version": "v3",
"created": "Mon, 3 Sep 2007 10:00:49 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lungwitz",
"Benjamin",
""
],
[
"Bleicher",
"Marcus",
""
]
] |
0707.1789 | Joaquim Prades | Joaquim Prades (Granada and CERN) | ChPT Progress on Non-Leptonic and Radiative Kaon Decays | 14 pages, 1 figure. Invited talk at KAON 07 International Conference,
May 21-25 2007, Frascati, Italy. v2: Discussion in Section 3 somewhat
enlarged and added references. Matches published verion | PoSKAON:022,2008 | null | CERN-PH-TH/2007-108 | hep-ph hep-ex hep-lat | null | I discuss recent developments on non-leptonic and radiative kaon decays
mainly related to direct CP-violation within the combined ChPT and 1/N_c
expansion approaches. In particular, I review the status of K -> pi pi,
epsilon_K', direct CP-violating K+ -> 3 pi Dalitz plot slope g and decay rate
asymmetries, and the Standard Model prediction for Br(K_L -> pi0 e+ e-).
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 14:03:20 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Sep 2007 15:43:16 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Prades",
"Joaquim",
"",
"Granada and CERN"
]
] |
0707.1790 | Simone Secchi | Vivina Barutello, Simone Secchi, Enrico Serra | A note on the radial solutions for the supercritical Henon equation | 13 pages, 4 figures | null | 10.1016/j.jmaa.2007.10.052 | null | math.AP | null | We prove the existence of a positive radial solution for the H\'enon equation
with arbitrary growth. The solution is found by means of a shooting method and
turns out to be an increasing function of the radial variable. Some numerical
experiments suggest the existence of many positive oscillating solutions.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:32:41 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Barutello",
"Vivina",
""
],
[
"Secchi",
"Simone",
""
],
[
"Serra",
"Enrico",
""
]
] |
0707.1791 | Markus Gaass | M. Gaass, S. Nadj-Perge, Z. Radovi\'c, A. Bauer, M. Aprili, W.
Wegscheider, C. Strunk | Bistability in superconducting rings containing an inhomogeneous
Josephson junction | 5 pages, 4 figures | Phys. Rev. B 77, 024506 (2008) | 10.1103/PhysRevB.77.024506 | null | cond-mat.mes-hall | null | We investigate the magnetic response of a superconducting Nb ring containing
a ferromagnetic PdNi Josephson junction and a tunnel junction in parallel. A
doubling of the switching frequency is observed within certain intervals of the
external magnetic field. Assuming sinusoidal current-phase relations of both
junctions our model of a dc-SQUID embedded within a superconducting ring
explains this feature by a sequence of current reversals in the ferromagnetic
section of the junction in these field intervals. The switching anomalies are
induced by the coupling between the magnetic fluxes in the two superconducting
loops.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:32:57 GMT"
}
] | 2010-02-10T00:00:00 | [
[
"Gaass",
"M.",
""
],
[
"Nadj-Perge",
"S.",
""
],
[
"Radović",
"Z.",
""
],
[
"Bauer",
"A.",
""
],
[
"Aprili",
"M.",
""
],
[
"Wegscheider",
"W.",
""
],
[
"Strunk",
"C.",
""
]
] |
0707.1792 | Gilles Chabrier | Gilles Chabrier, Jose Gallardo, Isabelle Baraffe (CRAL, ENS-Lyon) | Evolution of low-mass star and brown dwarf eclipsing binaries | to appear in A&A Letters | Astron.Astrophys.472:L17-L20,2007 | 10.1051/0004-6361:20077702 | null | astro-ph | null | We examine the evolution of low-mass star and brown dwarf eclipsing binaries.
These objects are rapid rotators and are believed to shelter large magnetic
fields. We suggest that reduced convective efficiency, due to fast rotation and
large field strengths, and/or to magnetic spot coverage of the radiating
surface significantly affect their evolution, leading to a reduced heat flux
and thus larger radii and cooler effective temperatures than for regular
objects. We have considered such processes in our evolutionary calculations,
using a phenomenological approach. This yields mass-radius and effective
temperature-radius relationships in agreement with the observations. We also
reproduce the effective temperature ratio and the radii of the two components
of the recently discovered puzzling eclipsing brown dwarf system. These
calculations show that fast rotation and/or magnetic activity may significantly
affect the evolution of eclipsing binaries and that the mechanical and thermal
properties of these objects depart from the ones of non-active low-mass
objects. We find that, for internal field strengths compatible with the
observed surface value of a few kiloGauss, convection can be severely
inhibited. The onset of a central radiative zone for rapidly rotating active
low-mass stars might thus occur below the usual $\sim 0.35 \msol$ limit.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:38:40 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Chabrier",
"Gilles",
"",
"CRAL, ENS-Lyon"
],
[
"Gallardo",
"Jose",
"",
"CRAL, ENS-Lyon"
],
[
"Baraffe",
"Isabelle",
"",
"CRAL, ENS-Lyon"
]
] |
0707.1793 | Jodie Martin | Jodie R. Martin (1), Robert W. O'Connell (1), J. E. Hibbard (2) ((1)
University of Virginia Charlottesville, VA, (2) National Radio Astronomy
Observatory Charlottesville, VA) | Near-UV Merger Signatures in Early-Type Galaxies | 6 pages, 2 figures. To appear in ``New Quests in Stellar Astrophysics
II, Ultraviolet Properties of Evolved Stellar Populations'', Eds M. Chavez,
E. Bertone, D. Rosa-Gonzalez and L. H. Rodriguez-Merino, Springer-Verlag | null | null | null | astro-ph | null | Hierarchical assembly of early-type galaxies (Es and S0s) over an extended
period of time will result in mixed-generation stellar populations. Here we
look for signatures of composite populations in broad-band, near-ultraviolet
(2500-3400 A), high-resolution HST imaging of the cores of 12 bright early-type
galaxies without obvious dust or active galactic nuclei. Near-UV imaging is a
sensitive probe for the detection of younger components with ages in the range
of 10 Myr to 5 Gyr. Only two galaxies have central colors (r < 0.75 r_eff) that
are consistent with a single-generation population. The other ten require a
composite population.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:43:32 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Martin",
"Jodie R.",
""
],
[
"O'Connell",
"Robert W.",
""
],
[
"Hibbard",
"J. E.",
""
]
] |
0707.1794 | Tanja Horn | T. Horn, et al | Scaling study of the pion electroproduction cross sections and the pion
form factor | 6 pages, 3 figures | Phys.Rev.C78:058201,2008 | 10.1103/PhysRevC.78.058201 | JLAB-PHY-07-679 | nucl-ex | null | The $^{1}$H($e,e^\prime \pi^+$)n cross section was measured for a range of
four-momentum transfer up to $Q^2$=3.91 GeV$^2$ at values of the invariant
mass, $W$, above the resonance region. The $Q^2$-dependence of the longitudinal
component is consistent with the $Q^2$-scaling prediction for hard exclusive
processes. This suggests that perturbative QCD concepts are applicable at
rather low values of $Q^2$. Pion form factor results, while consistent with the
$Q^2$-scaling prediction, are inconsistent in magnitude with perturbative QCD
calculations. The extraction of Generalized Parton Distributions from hard
exclusive processes assumes the dominance of the longitudinal term. However,
transverse contributions to the cross section are still significant at
$Q^2$=3.91 GeV$^2$.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:45:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Horn",
"T.",
""
]
] |
0707.1795 | Heinz-Peter Breuer | Heinz-Peter Breuer and Francesco Petruccione | Stochastic analysis and simulation of spin star systems | 8 pages, 2 figures | Phys. Rev. E 76, 016701 (2007) | 10.1103/PhysRevE.76.016701 | null | quant-ph | null | We discuss two methods of an exact stochastic representation of the
non-Markovian quantum dynamics of open systems. The first method employs a pair
of stochastic product vectors in the total system's state space, while the
second method uses a pair of state vectors in the open system's state space and
a random operator acting on the state space of the environment. Both techniques
lead to an exact solution of the von Neumann equation for the density matrix of
the total system. Employing a spin star model describing a central spin coupled
to bath of surrounding spins, we perform Monte Carlo simulations for both
variants of the stochastic dynamics. In addition, we derive analytical
expression for the expectation values of the stochastic dynamics to obtain the
exact solution for the density matrix of the central spin.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 13:56:00 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Breuer",
"Heinz-Peter",
""
],
[
"Petruccione",
"Francesco",
""
]
] |
0707.1796 | Shivaji Dasgupta | S. Dasgupta (1), C. Knaak (1), J. Moser (1), M. Bichler (1), S. F.
Roth (1), A. Fontcuberta i Morral (1), G. Abstreiter (1) and M. Grayson (1,2)
((1) Walter Schottky Institut, Technische Universitaet Muenchen, Garching,
Germany,(2) Department of Electrical Engineering and Computer Science,
Northwestern University, Evanston, IL USA) | Donor binding energy and thermally activated persistent
photoconductivity in high mobility (001) AlAs quantum wells | The values of binding energy changed from previous versions because
of a better understanding for the dielectric permittivity. Also, the Gamma -
X donor states are better explained | APL 91, 142120 (2007) | 10.1063/1.2794012 | null | cond-mat.mes-hall | null | A doping series of AlAs (001) quantum wells with Si delta-modulation doping
on both sides reveals different dark and post-illumination saturation
densities, as well as temperature dependent photoconductivity. The lower dark
two-dimensional electron density saturation is explained assuming deep binding
energy of Delta_DK = 65.2 meV for Si-donors in the dark. Persistent
photoconductivity (PPC) is observed upon illumination, with higher saturation
density indicating shallow post-illumination donor binding energy. The
photoconductivity is thermally activated, with 4 K illumination requiring
post-illumination annealing to T = 30 K to saturate the PPC. Dark and
post-illumination doping efficiencies are reported.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 09:06:28 GMT"
},
{
"version": "v2",
"created": "Tue, 24 Jul 2007 12:51:52 GMT"
},
{
"version": "v3",
"created": "Wed, 25 Jul 2007 15:09:28 GMT"
},
{
"version": "v4",
"created": "Tue, 18 Sep 2007 09:43:08 GMT"
}
] | 2008-02-27T00:00:00 | [
[
"Dasgupta",
"S.",
""
],
[
"Knaak",
"C.",
""
],
[
"Moser",
"J.",
""
],
[
"Bichler",
"M.",
""
],
[
"Roth",
"S. F.",
""
],
[
"Morral",
"A. Fontcuberta i",
""
],
[
"Abstreiter",
"G.",
""
],
[
"Grayson",
"M.",
""
]
] |
0707.1797 | Clovis Jacinto de Matos | Clovis Jacinto de Matos and Christian Beck | Possible Measurable Effects of Dark Energy in Rotating Superconductors | 22 pages | null | 10.1155/2009/931920 | null | gr-qc astro-ph cond-mat.supr-con hep-th | null | We discuss recent laboratory experiments with rotating superconductors and
show that three so far unexplained experimentally observed effects (anomalous
acceleration signals, anomalous gyroscope signals, Cooper pair mass excess) can
be physically explained in terms of a possible interaction of dark energy with
Cooper pairs. Our approach is based on a Ginzburg-Landau-like model of
electromagnetic dark energy, where gravitationally active photons obtain mass
in the superconductor. We show that this model can account simultaneously for
the anomalous acceleration and anomalous gravitomagnetic fields around rotating
superconductors measured by Tajmar et al. and for the anomalous Cooper pair
mass in superconductive Niobium, measured by Cabrera and Tate. It is argued
that these three different physical effects are ultimately different
experimental manifestations of the simultaneous spontaneous breaking of gauge
invariance, and of the principle of general covariance in superconductive
materials.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 14:00:23 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"de Matos",
"Clovis Jacinto",
""
],
[
"Beck",
"Christian",
""
]
] |
0707.1798 | Rainer Grauer | Christoph Beetz, Christian Schwarz, J\"urgen Dreher, Rainer Grauer | Density-PDFs and Lagrangian Statistics of highly compressible Turbulence | null | null | 10.1016/j.physleta.2008.01.009 | null | physics.flu-dyn | null | We report on probability-density-functions (PDF) of the mass density in
numerical simulations of highly compressible hydrodynamic flows and the
corresponding structure formation of Lagrangian particles advected by the
flows. Numerical simulations were performed with $512^3$ collocation points and
2 million tracer particles integrated over several dynamical times. We propose
a connection between the PDF of the Lagrangian tracer particles and the
predicted log-normal distribution of the density fluctuations in isothermal
systems.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 14:04:10 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Beetz",
"Christoph",
""
],
[
"Schwarz",
"Christian",
""
],
[
"Dreher",
"Jürgen",
""
],
[
"Grauer",
"Rainer",
""
]
] |
0707.1799 | Everton Murilo Carvalho Abreu | A.A. Deriglazov, C. Neves, W. Oliveira, E.M.C. Abreu, C. Wotzasek and
C. Filgueiras | Open string with a background B-field as the first order mechanics,
noncommutativity and soldering formalism | Revtex4, 8 pages. To appear in Physical Review D | Phys.Rev.D76:064007,2007 | 10.1103/PhysRevD.76.064007 | null | hep-th | null | To study noncommutativity properties of the open string with constant B-field
we construct a mechanical action which reproduces classical dynamics of the
string sector under consideration. It allows one to apply the Dirac
quantization procedure for constrained systems in a direct and unambiguous way.
The mechanical action turns out to be the first order system without taking the
strong field limit $B\longrightarrow\infty$. In particular, it is true for zero
mode of the string coordinate which means that the noncommutativity is
intrinsic property of this mechanical system. We describe the arbitrariness in
the relation existent between the mechanical and the string variables and show
that noncommutativity of the string variables on the boundary can be removed.
It is in correspondence with the result of Seiberg and Witten on relation among
noncommutative and ordinary Yang-Mills theories. The recently developed
soldering formalism helps us to establish a connection between the original
open string action and the Polyakov action.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 14:11:07 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Deriglazov",
"A. A.",
""
],
[
"Neves",
"C.",
""
],
[
"Oliveira",
"W.",
""
],
[
"Abreu",
"E. M. C.",
""
],
[
"Wotzasek",
"C.",
""
],
[
"Filgueiras",
"C.",
""
]
] |
0707.1800 | Ivana Agnolin | I. Agnolin, J.-N. Roux | On the elastic moduli of three-dimensional assemblies of spheres:
characterization and modeling of fluctuations in the particle displacement
and rotation | Submitted to IJSS | Int.Journ.Solids Structures (2007), Vol 45/3-4 pp 1101-1123 | 10.1016/j.ijsolstr.2007.07.016 | null | cond-mat.mtrl-sci cond-mat.dis-nn cond-mat.stat-mech | null | The elastic moduli of four numerical random isotropic packings of Hertzian
spheres are studied. The four samples are assembled with different preparation
procedures, two of which aim to reproduce experimental compaction by vibration
and lubrication. The mechanical properties of the samples are found to change
with the preparation history, and to depend much more on coordination number
than on density.
Secondly, the fluctuations in the particle displacements from the average
strain are analysed, and the way they affect the macroscopic behavior analyzed.
It is found that only the average over equally oriented contacts of the
relative displacement these fluctuations induce is relevant at the macroscopic
scale. This average depends on coordination number, average geometry of the
contact network and average contact stiffness. As far as the separate
contributions from particle displacements and rotations are concerned, the
former is found to counteract the average strain along the contact normal,
while the latter do in the tangential plane. Conversely, the tangential
components of the center displacements mainly arise to enforce local
equilibrium, and have a small, and generally stiffening effect at the
macro-scale.
Finally, the fluctuations and the shear modulus that result from two
approaches available in the literature are estimated numerically. These
approaches are both based on the equilibrium of a small-sized representative
assembly. The improvement of these estimate with respect to the average strain
assumption indicates that the fluctuations relevant to the macroscopic behavior
occur with short correlation length.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 14:27:29 GMT"
}
] | 2007-11-19T00:00:00 | [
[
"Agnolin",
"I.",
""
],
[
"Roux",
"J. -N.",
""
]
] |
0707.1801 | Diane Maclagan | Angela Gibney and Diane Maclagan | Equations for Chow and Hilbert Quotients | 26 pages, 1 figure. Exposition improved | null | null | null | math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We give explicit equations for the Chow and Hilbert quotients of a projective
scheme X by the action of an algebraic torus T in an auxiliary toric variety.
As a consequence we provide GIT descriptions of these canonical quotients, and
obtain other GIT quotients of X by variation of GIT quotient. We apply these
results to find equations for the moduli space \bar{M}_{0,n} of stable genus
zero n-pointed curves as a subvariety of a smooth toric variety defined via
tropical methods.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 14:40:39 GMT"
},
{
"version": "v2",
"created": "Fri, 29 May 2009 21:45:41 GMT"
}
] | 2009-05-30T00:00:00 | [
[
"Gibney",
"Angela",
""
],
[
"Maclagan",
"Diane",
""
]
] |
0707.1802 | Paolo Maria Santini | S. V. Manakov, P. M. Santini | On the solutions of the dKP equation: nonlinear Riemann Hilbert problem,
longtime behaviour, implicit solutions and wave breaking | 33 pages, 10 figures, few formulas updated | null | 10.1088/1751-8113/41/5/055204 | null | nlin.SI | null | We make use of the nonlinear Riemann Hilbert problem of the dispersionless
Kadomtsev Petviashvili equation, i) to construct the longtime behaviour of the
solutions of its Cauchy problem; ii) to characterize a class of implicit
solutions; iii) to elucidate the spectral mechanism causing the gradient
catastrophe of localized solutions, at finite time as well as in the longtime
regime, and the corresponding universal behaviours near breaking.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 14:47:53 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 13:05:30 GMT"
},
{
"version": "v3",
"created": "Tue, 20 Nov 2007 10:45:31 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Manakov",
"S. V.",
""
],
[
"Santini",
"P. M.",
""
]
] |
0707.1803 | Israeloff Nathan E | P. S. Crider, M. R. Majewski, Jingyun Zhang, H. Oukris and N. E.
Israeloff | Local dielectric spectroscopy of near-surface glassy polymer dynamics | submitted | null | 10.1063/1.2825301 | null | cond-mat.soft cond-mat.dis-nn | null | A non-contact scanning-probe-microscopy method was used to probe local
near-surface dielectric susceptibility and dielectric relaxation in
poly-vinyl-acetate (PVAc) near the glass transition. Dielectric spectra were
measured from 10-4 Hz to 102 Hz as a function of temperature. The measurements
probed a 20 nm thick layer below the free-surface of a bulk film. A small (4 K)
reduction in glass transition temperature and moderate narrowing of the
distribution of relaxation times was found. In contrast to results for
ultra-thin-films confined on or between metallic electrodes, no reduction in
the dielectric strength was found, inconsistent with the immobilization of
slower modes.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:03:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Crider",
"P. S.",
""
],
[
"Majewski",
"M. R.",
""
],
[
"Zhang",
"Jingyun",
""
],
[
"Oukris",
"H.",
""
],
[
"Israeloff",
"N. E.",
""
]
] |
0707.1804 | Thomas Jarlborg | T. Jarlborg | Properties of high-T$_C$ copper oxides from the nearly-free electron
model | 4 pages, 4 figures, 1 table | null | 10.1103/PhysRevB.76.140504 | null | cond-mat.supr-con cond-mat.mtrl-sci | null | The generic band structure of high-T$_C$ copper oxides is simulated by the
nearly free-electron model (NFE) in two dimensions (2-D) with parameters from
band calculations. Interaction between phonons and spin waves will cause
potential modulations and pseudogaps, and the strength of the modulations, the
wave lengths and the doping, are all related. A Fermi-surface "arc" is found
for dynamic spin/phonon waves. The confinement of superconductivity between two
limiting dopings can be a result of competition with the pseudogap at low
doping and weak coupling at high doping.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:09:13 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Jarlborg",
"T.",
""
]
] |
0707.1805 | Rosanna Migliore | Rosanna Migliore, Kazuya Yuasa, Marina Guccione, Hiromichi Nakazato,
Antonino Messina | Diffusion and transfer of entanglement in an array of inductively
coupled flux qubits | 5 pages, 1 figure, to be published on Phys. Rev. B 2007 | null | 10.1103/PhysRevB.76.052501 | null | cond-mat.supr-con cond-mat.other quant-ph | null | A theoretical scheme to generate multipartite entangled states in a Josephson
planar-designed architecture is reported. This scheme improves the one
published in [Phys. Rev. B 74, 104503 (2006)] since it speeds up the generation
of W entangled states in an MxN array of inductively coupled Josephson flux
qubits by reducing the number of necessary steps. In addition, the same
protocol is shown to be able to transfer the W state from one row to the other.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:10:23 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Migliore",
"Rosanna",
""
],
[
"Yuasa",
"Kazuya",
""
],
[
"Guccione",
"Marina",
""
],
[
"Nakazato",
"Hiromichi",
""
],
[
"Messina",
"Antonino",
""
]
] |
0707.1806 | Lionel Bureau | Lionel Bureau (INSP) | Friction as a probe of surface properties of a polymer glass | null | Macromolecules 40, 25 (2007) 9197 | 10.1021/ma071544p | null | cond-mat.soft | null | We probe the temperature dependence of friction at the interface between a
glassy poly(methylmethacrylate) lens and a flat substrate coated with a
methyl-terminated self-assembled monolayer. The monolayer exhibits density
defects which act as pinning sites for the polymer chains. We show that the
shear response of such an interface supports the existence, at the surface of
the glassy polymer, of a nanometer-thick layer of mobile chains. Friction can
be ascribed to the interplay between viscouslike dissipation in this layer and
depinning of chains adsorbed on the substrate. We further show that the pinning
dynamics is controlled by \beta rotational motions localized at the interface.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:12:44 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 09:57:49 GMT"
}
] | 2007-12-06T00:00:00 | [
[
"Bureau",
"Lionel",
"",
"INSP"
]
] |
0707.1807 | Philip Kim | Y.-W. Tan, Y. Zhang, K. Bolotin, Y. Zhao, S. Adam, E.H. Hwang, S. Das
Sarma, H. L. Stormer, P. Kim | Measurement of Scattering Rate and Minimum Conductivity in Graphene | 4 pages 4 figures | Phys. Rev. Lett. 99, 246803 (2007) | 10.1103/PhysRevLett.99.246803 | null | cond-mat.mes-hall | null | The conductivity of graphene samples with various levels of disorder is
investigated for a set of specimens with mobility in the range of
$1-20\times10^3$ cm$^2$/V sec. Comparing the experimental data with the
theoretical transport calculations based on charged impurity scattering, we
estimate that the impurity concentration in the samples varies from $2-15\times
10^{11}$ cm$^{-2}$. In the low carrier density limit, the conductivity exhibits
values in the range of $2-12e^2/h$, which can be related to the residual
density induced by the inhomogeneous charge distribution in the samples. The
shape of the conductivity curves indicates that high mobility samples contain
some short range disorder whereas low mobility samples are dominated by long
range scatterers.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:28:31 GMT"
}
] | 2008-01-02T00:00:00 | [
[
"Tan",
"Y. -W.",
""
],
[
"Zhang",
"Y.",
""
],
[
"Bolotin",
"K.",
""
],
[
"Zhao",
"Y.",
""
],
[
"Adam",
"S.",
""
],
[
"Hwang",
"E. H.",
""
],
[
"Sarma",
"S. Das",
""
],
[
"Stormer",
"H. L.",
""
],
[
"Kim",
"P.",
""
]
] |
0707.1808 | Abass Sagna | Abass Sagna (PMA) | Universal L^s -rate-optimality of L^r-optimal quantizers by dilatation
and contraction | 26 pages | null | null | null | math.PR | null | Let $ r, s>0 $. For a given probability measure $P$ on $\mathbb{R}^d$, let
$(\alpha_n)_{n \geq 1}$ be a sequence of (asymptotically) $L^r(P)$- optimal
quantizers. For all $\mu \in \mathbb{R}^d $ and for every $\theta >0$, one
defines the sequence $(\alpha_n^{\theta, \mu})_{n \geq 1}$ by : $\forall n \geq
1, \alpha_n^{\theta, \mu} = \mu + \theta(\alpha_n - \mu) = \{\mu + \theta(a-
\mu), a \in \alpha_n \} $. In this paper, we are interested in the asymptotics
of the $L^s$-quantization error induced by the sequence $(\alpha_n^{\theta,
\mu})_{n \geq 1}$. We show that for a wide family of distributions, the
sequence $(\alpha_n^{\theta, \mu})_{n \geq 1}$ is $L^s$-rate-optimal. For the
Gaussian and the exponential distributions, one shows how to choose the
parameter $\theta$ such that $(\alpha_n^{\theta, \mu})_{n \geq 1}$ satisfies
the empirical measure theorem and probably be asymptotically $L^s$-optimal.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:15:59 GMT"
},
{
"version": "v2",
"created": "Mon, 19 Nov 2007 16:23:39 GMT"
}
] | 2007-11-19T00:00:00 | [
[
"Sagna",
"Abass",
"",
"PMA"
]
] |
0707.1809 | Bernard Le Stum | Bernard Le Stum (IRMAR) | The Overconvergent Site II. Cohomology | 27 pages | null | null | 0743 | math.AG | null | We prove that rigid cohomology can be computed as the cohomology of a site
analogous to the crystalline site. Berthelot designed rigid cohomology as a
common generalization of crystalline and Monsky-Washnitzer cohomology.
Unfortunately, unlike the former, the functoriality of the theory is not
built-in. We defined somewhere else the "overconvergent site" which is
functorially attached to an algebraic variety and proved that the category of
modules of finite presentation on this ringed site is equivalent to the
category of over- convergent isocrystals on the variety. We show here that
their cohomology also coincides.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:16:30 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Stum",
"Bernard Le",
"",
"IRMAR"
]
] |
0707.1810 | Pamela Morehouse | D.H. Miller, et al, CLEO Collaboration | Measurement of the eta-Meson Mass using psi(2S) --> eta J/psi | 10 pages postscript,also available through
http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PRL | Phys.Rev.Lett.99:122002,2007 | 10.1103/PhysRevLett.99.122002 | CLNS 07/2003, CLEO 07-9 | hep-ex | null | We measure the mass of the eta meson using psi(2S) --> eta J/psi events
acquired with the CLEO-c detector operating at the CESR e+e- collider. Using
the four decay modes eta --> gamma gamma, 3pi0, pi+pi-pi0, and pi+pi-gamma, we
find M(eta)=547.785 +- 0.017 +- 0.057 MeV, in which the first uncertainty is
statistical and the second systematic. This result has an uncertainty
comparable to the two most precise previous measurements and is consistent with
that of NA48, but is inconsistent at the level of 6.5sigma with the much
smaller mass obtained by GEM.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:16:46 GMT"
},
{
"version": "v2",
"created": "Mon, 24 Sep 2007 13:58:42 GMT"
}
] | 2010-04-08T00:00:00 | [
[
"Miller",
"D. H.",
""
],
[
"Collaboration",
"CLEO",
""
]
] |
0707.1811 | Francois Demontoux | Fran\c{c}ois Demontoux (LPIOM), Gilles Ruffi\'e (LPIOM), Jean Pierre
Wigneron (EPHYSE), Maria-Jos\'e Escorihuela (CESBIO), Jennifer Grant | Caract\'erisation \'electromagn\'etique de milieux h\'et\'erog\`enes
naturels - Application \`a la mesure de l'humidit\'e du sol par radiom\'etrie
micro-onde | null | JCMM2006 - Journ\'ees de caract\'erisation Micro-ondes et
mat\'eriaux (2006) D2 | null | null | physics.geo-ph | null | The work which we present takes place within the framework of mission SMOS of
the ESA which will consist to send a radiometer (1.4 GHz) in space. The goal of
the research which we propose is the improvement of the comprehension of the
effects of structure soil and litter. The effects of the litter and
heterogeneities of the ground are probably important but still are very
ignored. So we developed an experimental approach in laboratory and in situ.
That makes it possible to take measurements for various configurations
(frequency, temporal, polarization, incidence, Bi-statics, Brewster effect...)
and in term of surface conditions(homogeneous or heterogeneous ground, more or
less wet, presence of litter...). Measurements at the laboratory with waveguide
enabled us to characterize the various components of the geological structure
(ground, rocks) and to check the model of Dobson usually used.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:19:14 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Demontoux",
"François",
"",
"LPIOM"
],
[
"Ruffié",
"Gilles",
"",
"LPIOM"
],
[
"Wigneron",
"Jean Pierre",
"",
"EPHYSE"
],
[
"Escorihuela",
"Maria-José",
"",
"CESBIO"
],
[
"Grant",
"Jennifer",
""
]
] |
0707.1812 | Thierry Dubois | Thierry Dubois, Rachid Touzani | A numerical study of heat island flows in an open domain: Stationary
solutions | null | null | null | null | math.NA cs.NA physics.class-ph | null | We present two dimensional numerical simulations of a natural convection
problem in an unbounded domain. A thermal stratification is applied in the
vertical direction and the flow circulation is induced by a heat island located
on the ground. For this problem, thermal perturbations are convected in the
horizontal direction far from the heated element so that very elongated
computational domains have to be used in order to compute accurate numerical
solutions. To avoid this difficulty thermal sponge layers are added at the
vertical boundaries. With this approach, stationary solutions at $Ra\le 10^5$
are investigated. Boussinesq equations are discretized with a second-order
finite volume scheme on a staggered grid combined with a second-order
projection method for the time integration.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:22:12 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Dubois",
"Thierry",
""
],
[
"Touzani",
"Rachid",
""
]
] |
0707.1813 | Francois Demontoux | B\'en\'edicte Le Crom (IMS, EPHYSE - UR1263), Fran\c{c}ois Demontoux
(IMS), Gilles Ruffi\'e (IMS), Jean Pierre Wigneron (EPHYSE), Jennifer Grant | Caracterisation Electromagnetique De Materiaux Geologiques En Vue Du
Suivi De L'Humidite Des Sols Par Radiometrie Micro-Ondes | null | colloque TELECOM'2007 & 5^0 JFMMA, Maroc (16/03/2007) p-521 | null | null | physics.geo-ph | null | The work which we present takes place within the framework of mission SMOS of
the ESA which will consist to send a radiometer (1.4 GHz) in space. The goal of
the research which we propose is the improvement of the comprehension of the
effects of structures composed of soil and litter. The effects of the litter
and heterogeneities of the ground are probably important but still ignored. The
objective of this work was to study the dielectric properties of a type of
litter and ground in order to integrate these values into an analytical multi
layers model of soil. The objective is to characterize the effects of this
layer on the total multi layer system. This will make possible to lead to a
simple analytical formulation of a model of litter which can be integrated into
the calculation algorithm of SMOS in order to collect information on moisture
starting from measurements of emissivity
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:24:17 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Crom",
"Bénédicte Le",
"",
"IMS, EPHYSE - UR1263"
],
[
"Demontoux",
"François",
"",
"IMS"
],
[
"Ruffié",
"Gilles",
"",
"IMS"
],
[
"Wigneron",
"Jean Pierre",
"",
"EPHYSE"
],
[
"Grant",
"Jennifer",
""
]
] |
0707.1814 | Matthias Staudt U. | M. U. Staudt, M. Afzelius, H. de Riedmatten, S. R. Hastings-Simon, C.
Simon, R. Ricken, H. Suche, W. Sohler, N. Gisin | Interference of multi-mode photon echoes generated in spatially
separated solid-state atomic ensembles | null | Phys. Rev. Lett. 99, 173602 (2007) | 10.1103/PhysRevLett.99.173602 | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | High-visibility interference of photon echoes generated in spatially
separated solid-state atomic ensembles is demonstrated. The solid state
ensembles were LiNbO$_3$ waveguides doped with Erbium ions absorbing at 1.53
$\mu$m. Bright coherent states of light in several temporal modes (up to 3) are
stored and retrieved from the optical memories using two-pulse photon echoes.
The stored and retrieved optical pulses, when combined at a beam splitter, show
almost perfect interference, which demonstrates both phase preserving storage
and indistinguishability of photon echoes from separate optical memories. By
measuring interference fringes for different storage times, we also show
explicitly that the visibility is not limited by atomic decoherence. These
results are relevant for novel quantum repeaters architectures with photon echo
based multimode quantum memories.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:25:49 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Jun 2008 17:41:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Staudt",
"M. U.",
""
],
[
"Afzelius",
"M.",
""
],
[
"de Riedmatten",
"H.",
""
],
[
"Hastings-Simon",
"S. R.",
""
],
[
"Simon",
"C.",
""
],
[
"Ricken",
"R.",
""
],
[
"Suche",
"H.",
""
],
[
"Sohler",
"W.",
""
],
[
"Gisin",
"N.",
""
]
] |
0707.1815 | Francois Demontoux | Fran\c{c}ois Demontoux (IMS), B\'en\'edicte Le Crom (IMS), Gilles
Ruffi\'e (IMS), Jean Pierre Wigneron (EPHYSE), Jennifer Grant, Heather
Lawrence (IMS) | Etude D'Un Modele D'Inversion Liant L'Emissivite a L'Humidite Des Sols.
Contribution a la Mise Au Point De L'Algorithme De la Mission Smos | null | colloque TELECOM'2007 & 5^0 JFMMA, Maroc (16/03/2007) p-405 | null | null | physics.geo-ph | null | The work which we present takes place within the framework of mission SMOS of
the ESA which will consist to send a radiometer (1.4 GHz) in space. The goal of
the research which we propose is the improvement of the comprehension of the
effects of structure soil and litter. The effects of the litter and
heterogeneities of the ground are probably important but still ignored. Its
effect can be corrected via a simple radiative model. It is thus necessary to
set up an analytical model which would make it possible to correct the effect
of this additional layer. The objective of this article is to present the
analytical models which we retained to correct the effect of the vegetation and
the litter in order to know the emissivity of the bare soil. We developed a
numerical model (with software HFSS) of calculation of the emissivity of
multi-layer systems in order to validate the results of the forward inversion
models. Ranges of permittivity are introduced with the model in order to take
account of the disturbances related to measurement and the variation of the
water content of the layers.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:26:35 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Demontoux",
"François",
"",
"IMS"
],
[
"Crom",
"Bénédicte Le",
"",
"IMS"
],
[
"Ruffié",
"Gilles",
"",
"IMS"
],
[
"Wigneron",
"Jean Pierre",
"",
"EPHYSE"
],
[
"Grant",
"Jennifer",
"",
"IMS"
],
[
"Lawrence",
"Heather",
"",
"IMS"
]
] |
0707.1816 | {\L}ukasz Szulc | Lukasz Szulc | Open FRW model in Loop Quantum Cosmology | 12 pages, no figures, latex | Class.Quant.Grav.24:6191-6200,2007 | 10.1088/0264-9381/24/24/003 | null | gr-qc | null | Open FRW model in Loop Quantum Cosmology is under consideration. The left and
right invariant vector fields and holonomies along them are studied. It is
shown that in the hyperbolic geometry of $k=-1$ it is possible to construct a
suitable loop which provides us with quantum scalar constraint originally
introduced by Vandersloot. The quantum scalar constraint operator with negative
cosmological constant is proved to be essentially self-adjoint.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:51:37 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 08:44:09 GMT"
},
{
"version": "v3",
"created": "Mon, 29 Oct 2007 13:05:18 GMT"
},
{
"version": "v4",
"created": "Tue, 29 Jan 2008 16:57:08 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Szulc",
"Lukasz",
""
]
] |
0707.1817 | Jochum van der Bij | J.J. van der Bij and S. Dilcher | HEIDI and the unparticle | 4 pages | Phys.Lett.B655:183-184,2007 | 10.1016/j.physletb.2007.09.004 | null | hep-ph | null | We compare the HEIDI models with the unparticle models. We show that the
unparticle models are a limiting case of the HEIDI models. We discuss
consistency conditions.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:33:44 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"van der Bij",
"J. J.",
""
],
[
"Dilcher",
"S.",
""
]
] |
0707.1818 | Saharon Shelah's Office | Saharon Shelah | Large continuum, oracles | null | null | null | Shelah [Sh:895] | math.LO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Our main theorem is about iterated forcing for making the continuum larger
than aleph_2. We present a generalization of math.LO/0303294 which is dealing
with oracles for random, etc., replacing aleph_1, aleph_2 by lambda,lambda^+
(starting with lambda=lambda^{<lambda}>aleph_1). Well, instead of properness we
demand absolute c.c.c. So we get, e.g. the continuum is lambda^+ but we can get
cov(meagre)=lambda. We give some applications. As in math.LO/0303294, it is a
"partial" countable support iteration but it is c.c.c.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:36:22 GMT"
},
{
"version": "v2",
"created": "Wed, 3 Mar 2010 03:42:25 GMT"
}
] | 2010-03-03T00:00:00 | [
[
"Shelah",
"Saharon",
""
]
] |
0707.1819 | Giuseppe Vallone | Giuseppe Vallone, Enrico Pomarico, Francesco De Martini, Paolo
Mataloni | One-way quantum computation via manipulation of polarization and
momentum qubits in two-photon cluster states | RevTex4, 4 pages, 3 figures | null | 10.1002/lapl.200710140 | null | quant-ph | null | Four-qubit cluster states of two photons entangled in polarization and linear
momentum have been used to realize a complete set of single qubit rotations and
the C-NOT gate for equatorial qubits with high values of fidelity. By the
computational equivalence of the two degrees of freedom our result demonstrate
the suitability of two photon cluster states for rapid and efficient one-way
quantum computing.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:50:18 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Vallone",
"Giuseppe",
""
],
[
"Pomarico",
"Enrico",
""
],
[
"De Martini",
"Francesco",
""
],
[
"Mataloni",
"Paolo",
""
]
] |
0707.1820 | Arnaud Legout | Anwar Al Hamra (INRIA Sophia Antipolis / INRIA Rh\^one-Alpes), Arnaud
Legout (INRIA Sophia Antipolis / INRIA Rh\^one-Alpes), Chadi Barakat (INRIA
Sophia Antipolis / INRIA Rh\^one-Alpes) | Understanding the Properties of the BitTorrent Overlay | null | null | null | null | cs.NI | null | In this paper, we conduct extensive simulations to understand the properties
of the overlay generated by BitTorrent. We start by analyzing how the overlay
properties impact the efficiency of BitTorrent. We focus on the average peer
set size (i.e., average number of neighbors), the time for a peer to reach its
maximum peer set size, and the diameter of the overlay. In particular, we show
that the later a peer arrives in a torrent, the longer it takes to reach its
maximum peer set size. Then, we evaluate the impact of the maximum peer set
size, the maximum number of outgoing connections per peer, and the number of
NATed peers on the overlay properties. We show that BitTorrent generates a
robust overlay, but that this overlay is not a random graph. In particular, the
connectivity of a peer to its neighbors depends on its arriving order in the
torrent. We also show that a large number of NATed peers significantly
compromise the robustness of the overlay to attacks. Finally, we evaluate the
impact of peer exchange on the overlay properties, and we show that it
generates a chain-like overlay with a large diameter, which will adversely
impact the efficiency of large torrents.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:38:14 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Hamra",
"Anwar Al",
"",
"INRIA Sophia Antipolis / INRIA Rhône-Alpes"
],
[
"Legout",
"Arnaud",
"",
"INRIA Sophia Antipolis / INRIA Rhône-Alpes"
],
[
"Barakat",
"Chadi",
"",
"INRIA\n Sophia Antipolis / INRIA Rhône-Alpes"
]
] |
0707.1821 | Valmir Barbosa | Valmir C. Barbosa, Raul Donangelo, Sergio R. Souza | Emergence of scale-free behavior in networks from limited-horizon
linking and cost trade-offs | null | Physica A 387 (2008), 1016-1024 | 10.1016/j.physa.2007.09.048 | null | cond-mat.stat-mech | null | We study network growth from a fixed set of initially isolated nodes placed
at random on the surface of a sphere. The growth mechanism we use adds edges to
the network depending on strictly local gain and cost criteria. Only nodes that
are not too far apart on the sphere may be considered for being joined by an
edge. Given two such nodes, the joining occurs only if the gain of doing it
surpasses the cost. Our model is based on a multiplicative parameter lambda
that regulates, in a function of node degrees, the maximum geodesic distance
that is allowed between nodes for them to be considered for joining. For n
nodes distributed uniformly on the sphere, and for lambda*sqrt(n) within limits
that depend on cost-related parameters, we have found that our growth mechanism
gives rise to power-law distributions of node degree that are invariant for
constant lambda*sqrt(n). We also study connectivity- and distance-related
properties of the networks.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:38:30 GMT"
}
] | 2008-04-11T00:00:00 | [
[
"Barbosa",
"Valmir C.",
""
],
[
"Donangelo",
"Raul",
""
],
[
"Souza",
"Sergio R.",
""
]
] |
0707.1822 | Rob Ivison | Frank Helmich (SRON) and Rob Ivison (UK ATC/IfA, Edinburgh) | FIRI - a Far-Infrared Interferometer | Proposal developed by a large team of astronomers from Europe, USA
and Canada and submitted to the European Space Agency as part of "Cosmic
Vision 2015-2025" | Experimental Astronomy, 2009, Volume 23, Issue 1, pp.245-276 | 10.1007/s10686-008-9100-2 | null | astro-ph | null | Half of the energy ever emitted by stars and accreting objects comes to us in
the FIR waveband and has yet to be properly explored. We propose a powerful
Far-InfraRed Interferometer mission, FIRI, to carry out high-resolution imaging
spectroscopy in the FIR. This key observational capability is essential to
reveal how gas and dust evolve into stars and planets, how the first luminous
objects in the Universe ignited, how galaxies formed, and when super-massive
black holes grew. FIRI will disentangle the cosmic histories of star formation
and accretion onto black holes and will trace the assembly and evolution of
quiescent galaxies like our Milky Way. Perhaps most importantly, FIRI will
observe all stages of planetary system formation and recognise Earth-like
planets that may harbour life, via its ability to image the dust structures in
planetary systems. It will thus address directly questions fundamental to our
understanding of how the Universe has developed and evolved - the very
questions posed by ESA's Cosmic Vision.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:45:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Helmich",
"Frank",
"",
"SRON"
],
[
"Ivison",
"Rob",
"",
"UK ATC/IfA, Edinburgh"
]
] |
0707.1823 | Francois Demontoux | Jennifer Grant (EPHYSE - UR1263), Jean Pierre Wigneron (EPHYSE -
UR1263), A.A. Van De Griend, Fran\c{c}ois Demontoux (LPIOM), Gilles Ruffi\'e
(LPIOM), A. Della Vecchia, N. Skou, B\'en\'edicte Le Crom (EPHYSE, LPIOM) | Lband radiometric behaviour of pine forests for a variety of surface
moisture conditions | null | 2nd International Symposium Recent Advances in Quantitative Remote
Sensing, - RAQRS'II (27/09/2006) - | null | null | physics.geo-ph | null | From July-December 2004 the experimental campaign 'Bray 2004' was conducted
in the coniferous forest of Les Landes near Bordeaux, France, using a
multi-angle L-band (1.4 GHz) radiometer to measure upwelling radiation above
the forest. At the same time, ground measurements were taken of soil and litter
moisture content. This experiment was done in the context of the upcoming SMOS
mission in order to improve our understanding of the behaviour of the L-band
signal above forested areas. Very little information exists on this subject at
the moment, especially for varying hydrological conditions. Furthermore,
additional measurements were done at the University of Bordeaux (PIOM
laboratory) to determine the dielectric behaviour of a litter layer such as
that found at the Bray site. There is some evidence that this layer may have a
different influence on the L-band signal than either the soil or the
vegetation, however the exact behaviour of the litter layer and the extent of
its influence on the L-band signal are as yet unknown. This paper presents 1)
results of the Bray experiment describing the behaviour of the above-canopy
L-band emissivity for different conditions of ground moisture and 2) the
relationship between soil and litter moisture content and results of the
laboratory experiments on litter dielectric properties. Together this will give
a first insight into the L-band radiometric properties of the different forest
layers for varying hydrological conditions.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:41:51 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Grant",
"Jennifer",
"",
"EPHYSE - UR1263"
],
[
"Wigneron",
"Jean Pierre",
"",
"EPHYSE -\n UR1263"
],
[
"Van De Griend",
"A. A.",
"",
"LPIOM"
],
[
"Demontoux",
"François",
"",
"LPIOM"
],
[
"Ruffié",
"Gilles",
"",
"LPIOM"
],
[
"Della Vecchia",
"A.",
"",
"EPHYSE, LPIOM"
],
[
"Skou",
"N.",
"",
"EPHYSE, LPIOM"
],
[
"Crom",
"Bénédicte Le",
"",
"EPHYSE, LPIOM"
]
] |
0707.1824 | Damien Chablat | Leonid Slutski (CIM), Damien Chablat (IRCCyN), Jorge Angeles (CIM) | The Kinematics of Manipulators Built From Closed Planar Mechanisms | null | Proceedings of the IEEE/ASME International Conference on Advanced
Intelligent Mechatronics (19/08/1999) 531-536 | null | null | cs.RO | null | The paper discusses the kinematics of manipulators builts of planar closed
kinematic chains. A special kinematic scheme is extracted from the array of
these mechanisms that looks the most promising for the creation of different
types of robotic manipulators. The structural features of this manipulator
determine a number of its original properties that essentially simplify its
control. These features allow the main control problems to be effectively
overcome by application of the simple kinematic problems. The workspace and
singular configurations of a basic planar manipulator are studied. By using a
graphic simulation method, motions of the designed mechanism are examined. A
prototype of this mechanism was implemented to verify the proposed approach.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:42:46 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Slutski",
"Leonid",
"",
"CIM"
],
[
"Chablat",
"Damien",
"",
"IRCCyN"
],
[
"Angeles",
"Jorge",
"",
"CIM"
]
] |
0707.1825 | Steven Sam | Steven V. Sam | A solid angle polynomial with negative coefficients | withdrawn | null | null | null | math.CO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This article has been replaced by arXiv:0906.4031
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 18:14:18 GMT"
},
{
"version": "v2",
"created": "Mon, 22 Jun 2009 15:32:47 GMT"
}
] | 2009-06-22T00:00:00 | [
[
"Sam",
"Steven V.",
""
]
] |
0707.1826 | Ansgar Liebsch | A. Liebsch | Doping-driven Mott transition in La_{1-x}Sr_xTiO_3 via simultaneous
electron and hole doping of t2g subbands | 4 pages, 5 figures | Phys. Rev. B 77, 115115 (2008) | 10.1103/PhysRevB.77.115115 | null | cond-mat.str-el | null | The insulator to metal transition in LaTiO_3 induced by La substitution via
Sr is studied within multi-band exact diagonalization dynamical mean field
theory at finite temperatures. It is shown that weak hole doping triggers a
large interorbital charge transfer, with simultaneous electron and hole doping
of t2g subbands. The transition is first-order and exhibits phase separation
between insulator and metal. In the metallic phase, subband compressibilities
become very large and have opposite signs. Electron doping gives rise to an
interorbital charge flow in the same direction as hole doping. These results
can be understood in terms of a strong orbital depolarization.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 15:47:01 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Liebsch",
"A.",
""
]
] |
0707.1827 | Joseph Lazio | T. Joseph W. Lazio (NRL) and W. M. Farrell (NASA/GSFC) | Magnetospheric Emissions from the Planet Orbiting tau Boo: A Multi-Epoch
Search | 11 pages, 5 figures; AASTeX format; ApJ in press | null | 10.1086/519730 | NRL/JA/7210 | astro-ph | null | All of the solar system gas giants produce electron cyclotron masers, driven
by the solar wind impinging on their magnetospheres. Extrapolating to the
planet orbiting tau Boo, various authors have predicted that it may be within
the detection limits of the 4-meter wavelength (74 MHz) system on the Very
Large Array. This paper reports three epochs of observations of tau Boo. In no
epoch do we detect the planet; various means of determining the upper limit to
the emission yield single-epoch limits ranging from 135 to 300 mJy. We develop
a likelihood method for multi-epoch observations and use it to constrain
various radiation properties of the planet. Assuming that the planet does
radiate at our observation wavelength, its typical luminosity must be less than
about 10^{16} W, unless its radiation is highly beamed into a solid angle Omega
<< 1 sr. While within the range of luminosities predicted by various authors
for this planet, this value is lower than recent estimates which attempt to
take into account the stellar wind of tau Boo using the known properties of the
star itself. Electron cyclotron maser emission from solar systems planets is
beamed, but with characteristic solid angles of approximately 1 sr illuminated.
Future long-wavelength instruments (e.g., the Long Wavelength Array and the Low
Frequency Array) must be able to make typical flux density measurements on
short time scales (~ 15 min.) of approximately 25 mJy in order to improve these
constraints significantly.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 19:21:58 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lazio",
"T. Joseph W.",
"",
"NRL"
],
[
"Farrell",
"W. M.",
"",
"NASA/GSFC"
]
] |
0707.1828 | Stavros Garoufalidis | Stavros Garoufalidis | An extended version of additive K-theory | 9 pages, 1 figure | null | null | null | math.AG math.NT | null | There are two infinitesimal (i.e., additive) versions of the $K$-theory of a
field $F$: one was introduced by Cathelineau, which is an $F$-module, and
another one introduced by Bloch-Esnault, which is an $F^*$-module. Both
versions are equipped with a regulator map, when $F$ is the field of complex
numbers.
In our short paper we will introduce an extended version of Cathelineau's
group, and a complex-valued regulator map given by the entropy. We will also
give a comparison map between our extended version and Cathelineau's group.
Our results were motivated by two unrelated sources: Neumann's work on the
extended Bloch group (which is isomorphic to indecomposable $K_3$ of the
complex numbers), and the study of singularities of generating series of
hypergeometric multisums. Final version.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 16:06:49 GMT"
},
{
"version": "v2",
"created": "Tue, 6 Nov 2007 19:53:39 GMT"
}
] | 2007-11-06T00:00:00 | [
[
"Garoufalidis",
"Stavros",
""
]
] |
0707.1829 | Mayeul Arminjon | Mayeul Arminjon and Frank Reifler | Dirac equation: Representation independence and tensor transformation | 28 pages, standard LaTeX. v3: matches version accepted in the
Brazilian Journal of Physics: minor wording improvements, refs updated. v2:
Intro and Conclusion improved (novelty more emphasized). Uniqueness and
positive definiteness extended to any admissible affine coordinates. 10 new
refs | Braz.J.Phys.38:248-258,2008 | 10.1590/S0103-97332008000200007 | null | quant-ph gr-qc hep-th | null | We define and study the probability current and the Hamiltonian operator for
a fully general set of Dirac matrices in a flat spacetime with affine
coordinates, by using the Bargmann-Pauli hermitizing matrix. We find that with
some weak conditions on the affine coordinates, the current, as well as the
spectrum of the Dirac Hamiltonian, thus all of quantum mechanics, are
independent of that set. These results allow us to show that the tensor Dirac
theory, which transforms the wave function as a spacetime vector and the set of
Dirac matrices as a third-order affine tensor, is physically equivalent to the
genuine Dirac theory, based on the spinor transformation. The tensor Dirac
equation extends immediately to general coordinate systems, thus to
non-inertial (e.g. rotating) coordinate systems.
| [
{
"version": "v1",
"created": "Thu, 12 Jul 2007 16:11:29 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Dec 2007 08:55:05 GMT"
},
{
"version": "v3",
"created": "Thu, 10 Apr 2008 15:41:44 GMT"
}
] | 2011-08-31T00:00:00 | [
[
"Arminjon",
"Mayeul",
""
],
[
"Reifler",
"Frank",
""
]
] |
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