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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.0814 | Oleksii Pliukhin Mr | Roman Cherniha, Oleksii Pliukhin | New conditional symmetries and exact solutions of nonlinear
reaction-diffusion-convection equations. II | null | null | null | null | math-ph math.MP | null | In the first part of this paper math-ph/0612078, a complete description of
Q-conditional symmetries for two classes of reaction-diffusion-convection
equations with power diffusivities is derived. It was shown that all the known
results for reaction-diffusion equations with power diffusivities follow as
particular cases from those obtained in math-ph/0612078 but not vise versa. In
the second part the symmetries obtained in are successfully applied for
constructing exact solutions of the relevant equations. In the particular case,
new exact solutions of nonlinear reaction-diffusion-convection (RDC) equations
arising in application and their natural generalizations are found.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 12:48:11 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Cherniha",
"Roman",
""
],
[
"Pliukhin",
"Oleksii",
""
]
] |
0706.0815 | Herbert Spohn | Herbert Spohn | Energy Current Correlations For Weakly Anharmonic Lattices | Contribution to ICMP 15, Rio de Janeiro, August 2006, 13 pages | null | null | null | math-ph math.MP | null | We discuss energy current correlations in thermal equilibrium and point out
the linkage to the fluctuating Peierls equation.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 12:58:48 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Spohn",
"Herbert",
""
]
] |
0706.0816 | Alexandros Alexakis | Alexandros Alexakis | Nonlocal Phenomenology for anisotropic MHD turbulence | Submited to Astophys. Lett | null | 10.1086/522048 | null | physics.flu-dyn | null | A non-local cascade model for anisotropic MHD turbulence in the presence of a
guiding magnetic field is proposed. The model takes into account that (a)
energy cascades in an anisotropic manner and as a result a different estimate
for the cascade rate in the direction parallel and perpendicular to the guiding
field is made. (b) the interactions that result in the cascade are between
different scales. Eddies with wave numbers $k_\|$ and $k_\perp$ interact with
eddies with wave numbers $q_\|,q_\perp$ such that a resonance condition between
the wave numbers $q_\|,q_\perp$ and $k_\|,k_\perp$ holds. As a consequence
energy from the eddy with wave numbers $k_\|$ and $k_\perp$ cascades due to
interactions with eddies located in the resonant manifold whose wavenumbers are
determined by: $q_\|\simeq \epsilon^{{1}/{3}}k_\perp^{2/3}/B$,
$q_\perp=k_\perp$ and energy will cascade along the lines $k_\|\sim
C+k_\perp^{2/3} \epsilon^{1/3}/B_0$. For a uniform energy injection rate in the
parallel direction the resulting energy spectrum is $E(k_\|,k_\perp)\simeq
\epsilon^{2/3}k_\|^{-1}k_\perp^{-5/3}$. For a general forcing however the model
suggests a non-universal behavior. The connections with previous models,
numerical simulations and weak turbulence theory are discussed.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 12:59:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Alexakis",
"Alexandros",
""
]
] |
0706.0817 | Pascal Moyal | Pascal Moyal | Measure-valued stochastic recurrences and the stability of queues | This paper has been withdrawn by the author. This paper has been
published in a newer version, arXiv:0803.2459 | null | null | null | math.PR | null | In this paper we present a stability criterion for finite measure-valued
stochastic recursions, generalizing Loynes's Theorem to spaces of measures.
This result provides conditions for the reach of a "total stationary state" for
the queue with an infinity of servers and the single-server SRPT queue. Indeed,
we give in both cases a condition of existence of a stationary measure-valued
recursive sequence characterizing the queueing system exhaustively.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:04:30 GMT"
},
{
"version": "v2",
"created": "Tue, 7 Sep 2010 09:05:21 GMT"
}
] | 2010-09-08T00:00:00 | [
[
"Moyal",
"Pascal",
""
]
] |
0706.0818 | Hagai Netzer | Hagai Netzer, Dieter Lutz, Mario Schweitzer, Alessandra Contursi,
Eckhard Sturm, Linda J. Tacconi, Sylvain Veilleux, D.-C. Kim, David Rupke,
Andrew J. Baker, Kalliopi Dasyra, Joseph Mazzarella, Steven Lord | Spitzer Quasar and ULIRG Evolution Study (QUEST): II. The Spectral
Energy Distributions of Palomar-Green Quasars | 12 pages, 6 figures, accepted by ApJ | Astrophys.J.666:806-816,2007 | 10.1086/520716 | null | astro-ph | null | This is the second paper studying the QSOs in the spitzer QUEST sample.
Previously we presented new PAH measurements and argued that most of the
observed far infrared (FIR) radiation is due to star-forming activity. Here we
present spectral energy distributions (SEDs) by supplementing our data with
optical, NIR and FIR observations. We define two sub-groups of ``weak FIR'' and
``strong FIR'' QSOs, and a third group of FIR non-detections. Assuming a
starburst origin for the FIR, we obtain ``intrinsic'' AGN SEDs by subtracting a
starburst template from the mean SEDs. The resulting SEDs are remarkably
similar for all groups. They show three distinct peaks corresponding to two
silicate emission features and a 3mic bump that we interpret as the signature
of the hottest AGN dust. They also display drops beyond 20mic that we interpret
as the signature of the minimum temperature (about 200K) dust. This component
must be optically thin to explain the silicate emission and the slope of the
long wavelength continuum. We discuss the merits of an alternative model where
most of the FIR emission is due to AGN heating. Such models are unlikely to
explain the properties of our QSOs but they cannot be ruled out for more
luminous objects. We also find correlations between the luminosity at 5100A and
two infrared starburst indicators: L(60mic) and L(PAH 7.7mic). The correlation
of L(5100A) with L(60mic) can be used to measure the relative growth rates and
lifetimes of the black hole and the new stars.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:11:20 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Netzer",
"Hagai",
""
],
[
"Lutz",
"Dieter",
""
],
[
"Schweitzer",
"Mario",
""
],
[
"Contursi",
"Alessandra",
""
],
[
"Sturm",
"Eckhard",
""
],
[
"Tacconi",
"Linda J.",
""
],
[
"Veilleux",
"Sylvain",
""
],
[
"Kim",
"D. -C.",
""
],
[
"Rupke",
"David",
""
],
[
"Baker",
"Andrew J.",
""
],
[
"Dasyra",
"Kalliopi",
""
],
[
"Mazzarella",
"Joseph",
""
],
[
"Lord",
"Steven",
""
]
] |
0706.0819 | Valeria Banica | Valeria Banica (DP), Luis Vega (BILBAO) | On the Dirac delta as initial condition for nonlinear Schr\"odinger
equations | 17 pages, to appear in in AnIHP Ann Non Lin | null | 10.1016/j.anihpc.2007.03.007 | null | math.AP | null | In this article we will study the initial value problem for some
Schr\"odinger equations with Diraclike initial data and therefore with infinite
L2 mass, obtaining positive results for subcritical nonlinearities. In the
critical case and in one dimension we prove that after some renormalization the
corresponding solution has finite energy. This allows us to conclude a
stability result in the defocusing setting. These problems are related to the
existence of a singular dynamics for Schr\"odinger maps through the so called
Hasimoto transformation.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:12:55 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Banica",
"Valeria",
"",
"DP"
],
[
"Vega",
"Luis",
"",
"BILBAO"
]
] |
0706.0820 | Libor Snobl | Cecilia Albertsson, Ladislav Hlavaty and Libor Snobl | On the Poisson-Lie T-plurality of boundary conditions | 25 pages, LaTeX; major revision, discussion of boundary fields added;
author's version of the published paper | J.Math.Phys.49:032301,2008 | 10.1063/1.2832622 | YITP-07-33 | hep-th | null | Conditions for the gluing matrix defining consistent boundary conditions of
two-dimensional nonlinear sigma-models are analyzed and reformulated.
Transformation properties of the right-invariant fields under Poisson-Lie
T-plurality are used to derive a formula for the transformation of the boundary
conditions. Examples of transformation of D-branes in two and three dimensions
are presented. We investigate obstacles arising in this procedure and propose
possible solutions.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:31:23 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 16:26:28 GMT"
},
{
"version": "v3",
"created": "Fri, 7 Mar 2008 14:21:07 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Albertsson",
"Cecilia",
""
],
[
"Hlavaty",
"Ladislav",
""
],
[
"Snobl",
"Libor",
""
]
] |
0706.0821 | Sergio Valencia Molina | S. Valencia, A. Gaupp, W. Gudat, Ll. Abad, Ll. Balcells and B.
Martinez | Magnetic dead layers in La2/3Ca1/3MnO3 thin films probed by X-ray
magnetic circular dichroism in reflection | 29 pages, 3 tables and 5 figures. submitted | null | null | null | cond-mat.mtrl-sci cond-mat.str-el | null | Surface magnetic properties of perovskite manganites have been a recurrent
topic during last years since they play a major role in the implementation of
magnetoelectronic devices. Magneto-optical techniques, such as X-ray magnetic
circular dichroism, turn out to be a very efficient tool to study surface
magnetism due to their sensitivity to magnetic and chemical variations across
the sample depth. Nevertheless, the application of the sum rules for the
determination of the spin magnetic moment might lead to uncertainties as large
as 40% in case of Mn ions. To overcome this problem we present an alternative
approach consisting of using X-ray magnetic circular dichroism in reflection
geometry. Fit of the data by using a computer code based in a 4X4 matrix
formalism leads to realistic results. In particular, we show that surface and
interface roughness are of major relevance for a proper description of the
experimental data and a correct interpretation of the results. By using such an
approach we demonstrate the presence of a narrow surface region with strongly
depressed magnetic properties in La2/3Ca1/3MnO3 thin films.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:32:31 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Valencia",
"S.",
""
],
[
"Gaupp",
"A.",
""
],
[
"Gudat",
"W.",
""
],
[
"Abad",
"Ll.",
""
],
[
"Balcells",
"Ll.",
""
],
[
"Martinez",
"B.",
""
]
] |
0706.0822 | Andrei Zelevinsky | Andrei Zelevinsky | Mutations for quivers with potentials: Oberwolfach talk, April 2007 | Part of Oberwolfach Report No. 22/2007 (Workshop on Algebraic Groups,
April 22 - 28, 2007) | null | null | null | math.RA math.AG math.RT | null | This is an extended abstract of my talk at the Oberwolfach Workshop
"Algebraic Groups" (April 22 - 28, 2007). It is based on a joint work with
H.Derksen and J.Weyman (arXiv:0704.0649v2 [math.RA]).
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:47:49 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Zelevinsky",
"Andrei",
""
]
] |
0706.0823 | Birger Horstmann | Birger Horstmann, Juan Ignacio Cirac, Tommaso Roscilde | Dynamics of Localization Phenomena for Hardcore Bosons in Optical
Lattices | 14 pages, 16 figures; added references, minor revisions; to appear in
Phys. Rev. A | Phys. Rev. A 76, 043625 (2007) | 10.1103/PhysRevA.76.043625 | null | cond-mat.str-el cond-mat.dis-nn | null | We investigate the behavior of ultracold bosons in optical lattices with a
disorder potential generated via a secondary species frozen in random
configurations. The statistics of disorder is associated with the physical
state in which the secondary species is prepared. The resulting random
potential, albeit displaying algebraic correlations, is found to lead to
localization of all single-particle states. We then investigate the real-time
dynamics of localization for a hardcore gas of mobile bosons which are brought
into sudden interaction with the random potential. Regardless of their initial
state and for any disorder strength, the mobile particles are found to reach a
steady state characterized by exponentially decaying off-diagonal correlations
and by the absence of quasi-condensation; when the mobile particles are
initially confined in a tight trap and then released in the disorder potential,
their expansion is stopped and the steady state is exponentially localized in
real space, clearly revealing Anderson localization.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:38:46 GMT"
},
{
"version": "v2",
"created": "Thu, 9 Aug 2007 12:16:17 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Horstmann",
"Birger",
""
],
[
"Cirac",
"Juan Ignacio",
""
],
[
"Roscilde",
"Tommaso",
""
]
] |
0706.0824 | Oleg Evnin | Ben Craps and Oleg Evnin | Quantum evolution across singularities | revised with an emphasis on local counterterm subtraction rather than
analyticity; version to be submitted for publication | JHEP 0804:021,2008 | 10.1088/1126-6708/2008/04/021 | null | hep-th | null | Attempts to consider evolution across space-time singularities often lead to
quantum systems with time-dependent Hamiltonians developing an isolated
singularity as a function of time. Examples include matrix theory in certain
singular time-dependent backgounds and free quantum fields on the
two-dimensional compactified Milne universe. Due to the presence of the
singularities in the time dependence, the conventional quantum-mechanical
evolution is not well-defined for such systems. We propose a natural way,
mathematically analogous to renormalization in conventional quantum field
theory, to construct unitary quantum evolution across the singularity. We carry
out this procedure explicitly for free fields on the compactified Milne
universe and compare our results with the matching conditions considered in
earlier work (which were based on the covering Minkowski space).
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:11:23 GMT"
},
{
"version": "v2",
"created": "Mon, 21 Jan 2008 17:41:42 GMT"
}
] | 2009-04-17T00:00:00 | [
[
"Craps",
"Ben",
""
],
[
"Evnin",
"Oleg",
""
]
] |
0706.0825 | Nicol\'as Grandi | D. C. Cabra, N. E. Grandi | Incidence of the boundary shape in the effective theory of fractional
quantum Hall edges | 12 pages, minor changes, replaced by published version | Phys.Rev. B77 (2008) 115107 | 10.1103/PhysRevB.77.115107 | null | cond-mat.mes-hall hep-th | null | Starting from a microscopic description of a system of strongly interacting
electrons in a strong magnetic field in a finite geometry, we construct the
boundary low energy effective theory for a fractional quantum Hall droplet
taking into account the effects of a smooth edge. The effective theory obtained
is the standard chiral boson theory (chiral Luttinger theory) with an
additional self-interacting term which is induced by the boundary. As an
example of the consequences of this model, we show that such modification leads
to a non-universal reduction in the tunnelling exponent which is independent of
the filling fraction. This is in qualitative agreement with experiments, that
systematically found exponents smaller than those predicted by the ordinary
chiral Luttinger liquid theory.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:51:18 GMT"
},
{
"version": "v2",
"created": "Wed, 21 May 2008 13:28:13 GMT"
}
] | 2009-08-13T00:00:00 | [
[
"Cabra",
"D. C.",
""
],
[
"Grandi",
"N. E.",
""
]
] |
0706.0826 | Yuliya V. Martsynyuk | Yuliya V. Martsynyuk | Central limit theorems in linear structural error-in-variables models
with explanatory variables in the domain of attraction of the normal law | Published at http://dx.doi.org/10.1214/07-EJS056 in the Electronic
Journal of Statistics (http://www.i-journals.org/ejs/) by the Institute of
Mathematical Statistics (http://www.imstat.org) | Electronic Journal of Statistics 2007, Vol. 1, 195-222 | 10.1214/07-EJS056 | IMS-EJS-EJS_2007_56 | math.ST stat.TH | null | Linear structural error-in-variables models with univariate observations are
revisited for studying modified least squares estimators of the slope and
intercept. New marginal central limit theorems (CLT's) are established for
these estimators, assuming the existence of four moments for the measurement
errors and that the explanatory variables are in the domain of attraction of
the normal law. The latter condition for the explanatory variables is used the
first time, and is so far the most general in this context. It is also optimal,
or nearly optimal, for our CLT's. Moreover, due to the obtained CLT's being in
Studentized and self-normalized forms to begin with, they are a priori nearly,
or completely, data-based, and free of unknown parameters of the joint
distribution of the error and explanatory variables. Consequently, they lead to
a variety of readily available, or easily derivable, large-sample approximate
confidence intervals (CI's) for the slope and intercept. In contrast, in
related CLT's in the literature so far, the variances of the limiting normal
distributions, in general, are complicated and depend on various, typically
unknown, moments of the error and explanatory variables. Thus, the
corresponding CI's for the slope and intercept in the literature, unlike those
of the present paper, are available only under some additional model
assumptions.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:52:17 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Martsynyuk",
"Yuliya V.",
""
]
] |
0706.0827 | Vojtech Kundrat | Vojtech Kundrat, Milos Lokajicek and Ivo Vrkoc | Limited validity of West and Yennie integral formula for elastic
scattering of hadrons | 5 pages | Phys.Lett.B656:182-185,2007 | 10.1016/j.physletb.2007.09.030 | null | hep-ph | null | The commonly used West and Yennie integral formula for the relative phase
between the Coulomb and elastic hadronic amplitudes might be consistently
applied to only if the hadronic amplitude had the constant ratio of the real to
the imaginary parts al all kinematically allowed values of four momentum
transfer squared.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 13:55:22 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kundrat",
"Vojtech",
""
],
[
"Lokajicek",
"Milos",
""
],
[
"Vrkoc",
"Ivo",
""
]
] |
0706.0828 | Steven Balbus | Steven A. Balbus, Pierre Henri | On the Magnetic Prandtl Number Behavior of Accretion Disks | 15 pages, 6 figures. Accepted for publication in the Astrophysical
Journal (February 10, 2008 issue.) Minor changes from original submission | null | 10.1086/524838 | null | astro-ph | null | We investigate the behavior of the magnetic Prandtl number (ratio of
microscopic viscosity to resistivity) for accretion sources. Generally this
number is very small in standard accretion disk models, but can become larger
than unity within $\sim 50$ Schwarzschild radii of the central mass. Recent
numerical investigations suggest a marked dependence of the level of MHD
turbulence on the value of the Prandtl number. Hence, black hole and neutron
star accretors, i.e. compact X-ray sources, are affected. The astrophysical
consequences of this could be significant, including a possible route to
understanding the mysterious state changes that have long characterized these
sources.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:00:29 GMT"
},
{
"version": "v2",
"created": "Thu, 25 Oct 2007 11:35:08 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Balbus",
"Steven A.",
""
],
[
"Henri",
"Pierre",
""
]
] |
0706.0829 | Ihor Lubashevsky | Ihor Lubashevsky, Rudolf Friedrich, Andrey Ushakov, Andreas Heuer | Generalized superstatistics of nonequilibrium Markovian systems | RevTeX 4, 7 figures, submitted to PRE | null | null | null | cond-mat.stat-mech cond-mat.dis-nn | null | The paper is devoted to the construction of the superstatistical description
for nonequilibrium Markovian systems. It is based on Kirchhoff's diagram
technique and the assumption on the system under consideration to possess a
wide variety of cycles with vanishing probability fluxes. The latter feature
enables us to introduce equivalence classes called channels within which
detailed balance holds individually. Then stationary probability as well as
flux distributions are represented as some sums over the channels. The latter
construction actually forms the superstatistical description, which, however,
deals with a certain superposition of equilibrium subsystems rather then is a
formal expansion of the nonequilibrium steady state distribution into terms of
the Boltzmann type.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:08:17 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Lubashevsky",
"Ihor",
""
],
[
"Friedrich",
"Rudolf",
""
],
[
"Ushakov",
"Andrey",
""
],
[
"Heuer",
"Andreas",
""
]
] |
0706.0830 | Matteo Maturi | M. Maturi, L. Moscardini, P. Mazzotta, K. Dolag, G. Tormen | The importance of the merging activity for the kinetic polarization of
the Sunyaev-Zel'dovich signal from galaxy clusters | 13 pages, 7 figures, submitted to A&A | null | 10.1051/0004-6361:20078015 | null | astro-ph | null | The polarization sensitivity of the upcoming millimetric observatories will
open new possibilities for studying the properties of galaxy clusters and for
using them as powerful cosmological probes. For this reason it is necessary to
investigate in detail the characteristics of the polarization signals produced
by their highly ionized intra-cluster medium (ICM). This work is focussed on
the polarization effect induced by the ICM bulk motions, the so-called kpSZ
signal, which has an amplitude proportional to the optical depth and to the
square of the tangential velocity. In particular we study how this polarization
signal is affected by the internal dynamics of galaxy clusters and what is its
dependence on the physical modelling adopted to describe the baryonic
component. This is done by producing realistic kpSZ maps starting from the
outputs of two different sets of high-resolution hydrodynamical N-body
simulations. The first set (17 objects) follows only non-radiative
hydrodynamics, while for each of 9 objects of the second set we implement four
different kinds of physical processes. Our results shows that the kpSZ signal
turns out to be a very sensitive probe of the dynamical status of galaxy
clusters. We find that major merger events can amplify the signal up to one
order of magnitude with respect to relaxed clusters, reaching amplitude up to
about 100 nuK. This result implies that the internal ICM dynamics must be taken
into account when evaluating this signal because simplicistic models, based on
spherical rigid bodies, may provide wrong estimates. Finally we find that the
dependence on the physical modelling of the baryonic component is relevant only
in the very inner regions of clusters.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:12:40 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Maturi",
"M.",
""
],
[
"Moscardini",
"L.",
""
],
[
"Mazzotta",
"P.",
""
],
[
"Dolag",
"K.",
""
],
[
"Tormen",
"G.",
""
]
] |
0706.0831 | Askin Ankay | Askin Ankay, Arzu M. Ankay, E. Nihal Ercan | Possible evolution of dim radio quiet neutron star 1E 1207.4-5209 based
on a B-decay model | 13 pages, 1 figure | Int.J.Mod.Phys.D16:619,2007 | 10.1142/S0218271807009383 | null | astro-ph | null | Dim radio-quiet neutron star (DRQNS) 1E 1207.4-5209 is one of the most
heavily examined isolated neutron stars. Wide absorption lines were observed in
its spectrum obtained by both XMM-Newton and Chandra X-ray satellites. These
absorption lines can be interpreted as a principal frequency centered at 0.7
keV and its harmonics at 1.4, 2.1 and possibly 2.8 keV. The principal line can
be formed by resonant proton cyclotron scattering leading to a magnetic field
which is two orders of magnitude larger than the perpendicular component of the
surface dipole magnetic field (B) found from the rotation period (P) and the
time rate of change in the rotation period (\.{P}) of 1E 1207.4-5209. Besides,
age of the supernova remnant (SNR) G296.5+10.0 which is physically connected to
1E 1207.4-5209 is two orders of magnitude smaller than the characteristic age
($\tau$=P/2\.{P}) of the neutron star. These huge differences between the
magnetic field values and the ages can be explained based on a B-decay model.
If the decay is assumed to be exponential, the characteristic decay time turns
out to be several thousand years which is three orders of magnitude smaller
than the characteristic decay time of radio pulsars represented in an earlier
work. The lack of detection of radio emission from DRQNSs and the lack of point
sources and pulsar wind nebulae in most of the observed SNRs can also be partly
explained by such a very rapid exponential decay. The large difference between
the characteristic decay times of DRQNSs and radio pulsars must be related to
the differences in the magnetic fields, equation of states and masses of these
isolated neutron stars.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:13:31 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Ankay",
"Askin",
""
],
[
"Ankay",
"Arzu M.",
""
],
[
"Ercan",
"E. Nihal",
""
]
] |
0706.0832 | Giovanni De Cesare Dr. | G. De Cesare, A. Bazzano, S. Martinez Nunez, G. Stratta, A. Tarana, M.
De Santo and P. Ubertini | INTEGRAL high energy monitoring of the X-ray burster KS 1741-293 | 7 pages, accepted for publication on MNRAS | null | 10.1111/j.1365-2966.2007.12076.x | null | astro-ph | null | KS 1741-293, discovered in 1989 by the X-ray camera TTM in the Kvant module
of the Mir space station and identified as an X-ray burster, has not been
detected in the hard X band until the advent of the INTEGRAL observatory.
Moreover this source has been recently object of scientific discussion, being
also associated to a nearby extended radio source that in principle could be
the supernova remnant produced by the accretion induced collapse in the binary
system. Our long term monitoring with INTEGRAL, covering the period from
February 2003 to May 2005, confirms that KS 1741-293 is transient in soft and
hard X band. When the source is active, from a simultaneous JEM-X and IBIS data
analysis, we provide a wide band spectrum from 5 to 100 keV, that can be fit by
a two component model, a multiple blackbody for the soft emission and a
Comptonized or a cut-off power law model for the hard component. Finally, by
the detection of two X-ray bursters with JEM-X, we confirm the bursting nature
of KS 1741-293, including this source in the class of the hard tailed X-ray
bursters.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:40:05 GMT"
},
{
"version": "v2",
"created": "Mon, 18 Jun 2007 16:11:44 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"De Cesare",
"G.",
""
],
[
"Bazzano",
"A.",
""
],
[
"Nunez",
"S. Martinez",
""
],
[
"Stratta",
"G.",
""
],
[
"Tarana",
"A.",
""
],
[
"De Santo",
"M.",
""
],
[
"Ubertini",
"P.",
""
]
] |
0706.0833 | Fumio Hiroshima | Fumio Hiroshima and Jozsef Lorinczi | Functional Integral Representation of the Pauli-Fierz Model with Spin
1/2 | This is a revised version. This paper will be published from J.
Funct. Anal | null | null | null | math-ph math.MP | null | A Feynman-Kac-type formula for a L\'evy and an infinite dimensional Gaussian
random process associated with a quantized radiation field is derived. In
particular, a functional integral representation of $e^{-t\PF}$ generated by
the Pauli-Fierz Hamiltonian with spin $\han$ in non-relativistic quantum
electrodynamics is constructed. When no external potential is applied $\PF$
turns translation invariant and it is decomposed as a direct integral $\PF =
\int_\BR^\oplus \PF(P) dP$. The functional integral representation of
$e^{-t\PF(P)}$ is also given. Although all these Hamiltonians include spin,
nevertheless the kernels obtained for the path measures are scalar rather than
matrix expressions. As an application of the functional integral
representations energy comparison inequalities are derived.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:26:58 GMT"
},
{
"version": "v2",
"created": "Wed, 16 Jan 2008 02:56:53 GMT"
}
] | 2008-01-16T00:00:00 | [
[
"Hiroshima",
"Fumio",
""
],
[
"Lorinczi",
"Jozsef",
""
]
] |
0706.0834 | Ludovic Pricoupenko | Ludovic Pricoupenko (LPTMC) | Resonant Scattering of Ultracold Atoms in Low Dimensions | null | Physical Review Letters 100 (2008) 170404 | 10.1103/PhysRevLett.100.170404 | null | cond-mat.other | null | Low energy scattering amplitudes for two atoms in one- and two-dimensional
atomic wave guides are derived for short range isotropic and resonant
interactions in high partial wave channels. Taking into account the finite
width of the resonance which was neglected in previous works is shown to have
important implications in the properties of the confinement induced resonances.
For spin polarized fermions in quasi-1D wave guides it imposes a strong
constraint on the atomic density for achieving the Fermi Tonks Girardeau gas.
For a planar wave guide, the charateristics of the 2D induced scattering
resonances in $p$- and d-wave are determined as a function of the 3D scattering
parameters and of the wave guide frequency.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:28:11 GMT"
},
{
"version": "v2",
"created": "Fri, 12 Oct 2007 15:01:23 GMT"
},
{
"version": "v3",
"created": "Mon, 2 Jun 2008 09:37:22 GMT"
}
] | 2008-06-02T00:00:00 | [
[
"Pricoupenko",
"Ludovic",
"",
"LPTMC"
]
] |
0706.0835 | Giorgos Fagas | Giorgos Fagas and James C. Greer | Tunnelling in alkanes anchored to gold electrodes via amine end groups | 9 pages, 3 figures, 1 table; to appear in Nanotechnology | Nanotechnology 18, 424010 (2007) | 10.1088/0957-4484/18/42/424010 | null | cond-mat.mtrl-sci cond-mat.other | null | For investigation of electron transport on the nanoscale, a system possessing
a simple to interpret electronic structure is composed of alkane chains
bridging two electrodes via end groups; to date the majority of experiments and
theoretical investigations on such structures have considered thiols bonding to
gold electrodes. Recently experiments show that well defined molecular
conductances may be resolved if the thiol end groups are replaced by amines. In
this theoretical study, we investigate the bonding of amine groups to gold
clusters and calculate electron transport across the resulting tunnel
junctions. We find very good agreement with recent experiments for alkane
diamines and discuss differences with respect to the alkane dithiol system.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:37:16 GMT"
}
] | 2007-10-01T00:00:00 | [
[
"Fagas",
"Giorgos",
""
],
[
"Greer",
"James C.",
""
]
] |
0706.0836 | Szymczak Marian | M. Szymczak, A. Bartkiewicz, E. Gerard | EVN observations of an OH maser burst in OH17.7-2.0 | 6 pages, 3 figures, Proceedings of the 8th European VLBI Network
Symposium, Torun, Poland, 26-29 Sep. 2006 | null | null | null | astro-ph | null | We have observed the OH 1612-MHz maser emission towards the proto-planetary
nebula candidate OH17.7-2.0 that underwent a very strong and unusual outburst
in 2003. Phase-referencing data were obtained with the EVN in order to localize
the outburst and to examine its possible causes. The majority of the emission
comes from an incomplete spherical shell with inner and outer radii of 220 and
850 mas, respectively. There is a strong evidence for maser components that
arise due to the interaction of a jet-like post-AGB outflow with the remnant
outer AGB shell. The most prominent signature of such an interaction is the
strongly bursting polarized emission near 73.3km/s coming from two unresolved
components of brightness temperature up to 10^11K located at the edge of the
biconal region 2500 AU from the central star. It is remarkable that this OH
biconal region is well-aligned with the polar outflow inferred from the
near-infrared image.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:47:36 GMT"
}
] | 2009-04-16T00:00:00 | [
[
"Szymczak",
"M.",
""
],
[
"Bartkiewicz",
"A.",
""
],
[
"Gerard",
"E.",
""
]
] |
0706.0837 | Stefka Cartaleva | C. Andreeva, S. Cartaleva, L. Petrov, S. M. Saltiel, D. Sarkisyan,
T.Varzhapetyan, D. Bloch, M. Ducloy | Saturation effects in the sub-Doppler spectroscopy of Cesium vapor
confined in an Extremely Thin Cell | 11 pages, 12 figures | null | 10.1103/PhysRevA.76.013837 | null | physics.class-ph | null | Saturation effects affecting absorption and fluorescence spectra of an atomic
vapor confined in an Extremely Thin Cell (cell thickness $L < 1 \mu m$) are
investigated experimentally and theoretically. The study is performed on the
$D_{2}$ line ($\lambda ~= ~852 nm)$ of $Cs$ and concentrates on the two
situations $L = \lambda /2$ and $L =\lambda$, the most contrasted ones with
respect to the length dependence of the coherent Dicke narrowing. For $L =
\lambda /2$, the Dicke-narrowed absorption profile simply broadens and
saturates in amplitude when increasing the light intensity, while for $L
=\lambda$, sub-Doppler dips of reduced absorption at line-center appear on the
broad absorption profile. For a fluorescence detection at $L =\lambda$,
saturation induces narrow dips, but only for hyperfine components undergoing a
population loss through optical pumping. These experimental results are
interpreted with the help of the various existing models, and are compared with
numerical calculations based upon a two-level modelling that considers both a
closed and an open system.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 14:58:32 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Andreeva",
"C.",
""
],
[
"Cartaleva",
"S.",
""
],
[
"Petrov",
"L.",
""
],
[
"Saltiel",
"S. M.",
""
],
[
"Sarkisyan",
"D.",
""
],
[
"Varzhapetyan",
"T.",
""
],
[
"Bloch",
"D.",
""
],
[
"Ducloy",
"M.",
""
]
] |
0706.0838 | Saibal Ray | Partha Chowdhury, P. C. Ray and Saibal Ray | Periodicity of ~155 days in solar electron fluence | 11 pages of PDF version of MSWORD, 3 figures with 1 table | Indian J.Phys.82:95-104,2008 | null | null | astro-ph | null | In this paper we have investigated the occurrence rate of high energetic(E>10
MeV) solar electron flares measured by IMP-8 spacecraft of NASA for solar cycle
21 (June, 1976 to August, 1986) first time by three different methods to detect
periodicities accurately. Power-spectrum analysis confirms a periodicity ~155
days which is in consistent with the result of Chowdhury and Ray (2006), that
"Rieger periodicity" was operated throughout the cycle 21 and it is independent
on the energy of the electron fluxes.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:01:28 GMT"
},
{
"version": "v2",
"created": "Thu, 7 Jun 2007 07:15:06 GMT"
}
] | 2018-11-20T00:00:00 | [
[
"Chowdhury",
"Partha",
""
],
[
"Ray",
"P. C.",
""
],
[
"Ray",
"Saibal",
""
]
] |
0706.0839 | Krzysztof Byczuk | Krzysztof Byczuk and Dieter Vollhardt | Correlated bosons on a lattice: Dynamical mean-field theory for
Bose-Einstein condensed and normal phases | 17 pages, 4 figures, extended version | Phys. Rev. B 77, 235106 (2008) | 10.1103/PhysRevB.77.235106 | null | cond-mat.other quant-ph | null | We formulate a bosonic dynamical mean-field theory (B-DMFT) which provides a
comprehensive, thermodynamically consistent framework for the theoretical
investigation of correlated lattice bosons. The B-DMFT is applicable for
arbitrary values of the coupling parameters and temperature and becomes exact
in the limit of high spatial dimensions d or coordination number Z of the
lattice. In contrast to its fermionic counterpart the construction of the
B-DMFT requires different scalings of the hopping amplitudes with Z depending
on whether the bosons are in their normal state or in the Bose-Einstein
condensate. A detailed discussion of how this conceptual problem can be
overcome by performing the scaling in the action rather than in the Hamiltonian
itself is presented. The B-DMFT treats normal and condensed bosons on equal
footing and thus includes the effects caused by their dynamic coupling. It
reproduces all previously investigated limits in parameter space such as the
Beliaev-Popov and Hartree-Fock-Bogoliubov approximations and generalizes the
existing mean-field theories of interacting bosons. The self-consistency
equations of the B-DMFT are those of a bosonic single-impurity coupled to two
reservoirs corresponding to bosons in the condensate and in the normal state,
respectively. We employ the B-DMFT to solve a model of itinerant and localized,
interacting bosons analytically. The local correlations are found to enhance
the condensate density and the Bose-Einstein condensate (BEC) transition
temperature T_{BEC}. This effect may be used experimentally to increase T_{BEC}
of bosonic atoms in optical lattices.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:21:11 GMT"
},
{
"version": "v2",
"created": "Tue, 11 Mar 2008 12:39:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Byczuk",
"Krzysztof",
""
],
[
"Vollhardt",
"Dieter",
""
]
] |
0706.0840 | Jean Michel Nunzi | Ajay K. Pandey and Jean-Michel Nunzi | Up-conversion injection in Rubrene/Perylene-diimide-heterostructure
electroluminescent diodes | we report the first evidence of an Auger-fountain electroluminescence
in a semiconductor heterojunction | Applied Physics Letters 90(26), 263508 (2007) | 10.1063/1.2752540 | null | cond-mat.mtrl-sci cond-mat.other | null | We implement and demonstrate a scheme that permits to drive
electroluminescence with an extremely low turn-on voltage. The device behaves
like compound semiconductors, in which the electroluminescence turn-on voltage
is about the same as the open circuit voltage for the photovoltaic effect.
However, the electroluminescence turn-on voltage is about half of the band gap
of the emitting material, that cannot be explained using current models of
charge injection in organic semiconductors. We hereby propose explanation
through an Auger-type two-step injection mechanism (Auger-fountain).
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:02:34 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pandey",
"Ajay K.",
""
],
[
"Nunzi",
"Jean-Michel",
""
]
] |
0706.0841 | Jerome Lelong | J\'er\^ome Lelong (CERMICS) | Almost sure convergence of randomly truncated stochastic algorithms
under verifiable conditions | null | Statistics & Probability Letters 78, 16 (2008) 2632-2636 | 10.1016/j.spl.2008.02.034 | null | math.PR | null | We study the almost sure convergence of randomly truncated stochastic
algorithms. We present a new convergence theorem which extends the already
known results by making vanish the classical condition on the noise terms. The
aim of this work is to prove an almost sure convergence result of randomly
truncated stochastic algorithms under easily verifiable conditions
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:16:31 GMT"
}
] | 2009-06-29T00:00:00 | [
[
"Lelong",
"Jérôme",
"",
"CERMICS"
]
] |
0706.0842 | Andrew Beckwith | A.W.Beckwith | Using quantum computing models for graviton communication/information
processing in cosmological evolution | 11 pages, no figures, copy of paper submitted directly to STAIF
conference for inclusion in 2008 | null | null | null | physics.gen-ph | null | In 2001, Seth Lloyd presented a radical new critique of the universe as a
quantum computing device, with an upper limit of bit calculations of the order
of 10 to the 120 power. We find that his calculations permit us to reconcile
the existance of a huge cosmological constant 10 to the minus 43 seconds after
the big bang, with a resulting huge relic graviton flux, with the existance of
a CMBR observational barrier of z = 1100 years after the big bang. Lloyd's
calculations pre suppose the existence of a huge entropy value during the
nucleation of a new universe, a datum we think helps shed light on the
cosmological landscape problem.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:32:51 GMT"
},
{
"version": "v2",
"created": "Sat, 7 Jul 2007 05:26:04 GMT"
}
] | 2007-07-07T00:00:00 | [
[
"Beckwith",
"A. W.",
""
]
] |
0706.0843 | Bero Roos | Lutz Mattner and Bero Roos | Maximal probabilities of convolution powers of discrete uniform
distributions | 6 pages | null | null | null | math.PR math.CA | null | We prove optimal constant over root $n$ upper bounds for the maximal
probabilities of $n$th convolution powers of discrete uniform distributions.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:45:25 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Mattner",
"Lutz",
""
],
[
"Roos",
"Bero",
""
]
] |
0706.0844 | Elizabeth Meckes | Elizabeth Meckes | Two multivariate central limit theorems | 10 pages | null | null | null | math.PR | null | In this paper, explicit error bounds are derived in the approximation of rank
$k$ projections of certain $n$-dimensional random vectors by standard
$k$-dimensional Gaussian random vectors. The bounds are given in terms of $k$,
$n$, and a basis of the $k$-dimensional space onto which we project. The random
vectors considered are two generalizations of the case of a vector with
independent, identically distributed components. In the first case, the random
vector has components which are independent but need not have the same
distribution. The second case deals with finite exchangeable sequences of
random variables.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 19:30:26 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Meckes",
"Elizabeth",
""
]
] |
0706.0845 | Debraj Chakrabarti | Debraj Chakrabarti, Rasul Shafikov | Holomorphic Extension of CR Functions from Quadratic Cones | A previous version of this article appeared in Mathematische Annalen,
and subsequently a short erratum appeared. This version incorporates the
(minor) changes given in the erratum | Math. Ann. (2008) 341:543-573 | null | null | math.CV | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is proved that CR functions on a quadratic cone M in $\C^n$, n>1, admit
one-sided holomorphic extension if and only if M does not have two-sided
support, a geometric condition on M which generalizes minimality in the sense
of Tumanov. A biholomorphic classification of quadratic cones in $\C^2$ is also
given.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:33:30 GMT"
},
{
"version": "v2",
"created": "Wed, 6 Jun 2007 20:17:40 GMT"
},
{
"version": "v3",
"created": "Mon, 30 Jul 2007 21:55:46 GMT"
},
{
"version": "v4",
"created": "Sun, 5 Aug 2007 00:32:07 GMT"
},
{
"version": "v5",
"created": "Thu, 29 Nov 2007 19:04:13 GMT"
},
{
"version": "v6",
"created": "Mon, 7 Mar 2011 18:56:01 GMT"
}
] | 2011-03-08T00:00:00 | [
[
"Chakrabarti",
"Debraj",
""
],
[
"Shafikov",
"Rasul",
""
]
] |
0706.0846 | Frank Glas | F. Glas, J.-C. Harmand and G. Patriarche (CNRS, Laboratoire de
Photonique et de Nanostructures, Marcoussis, France) | Why does wurtzite form in nanowires of III-V zinc-blende semiconductors? | 4 pages with 4 figures Submitted to Physical Review Letters | Physical Review Letters 99, 146101 (2007) | 10.1103/PhysRevLett.99.146101 | null | cond-mat.mtrl-sci | null | We develop a nucleation-based model to explain the formation of the wurtzite
(WZ) crystalline phase during the vapor-liquid-solid growth of free-standing
nanowires of zinc-blende (ZB) semiconductors. We first show that, in nanowires,
nucleation generally occurs at the outer edge of the solid/liquid interface
(the triple phase line) rather than elsewhere at the solid/liquid interface. In
the present case, this entails major differences between ZB and WZ nuclei.
Depending on the pertinent interface energies, WZ nucleation is favored at high
liquid supersaturation. This explains our systematic observation of ZB during
the early stages of nanowire growth.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:38:52 GMT"
}
] | 2007-10-10T00:00:00 | [
[
"Glas",
"F.",
"",
"CNRS, Laboratoire de\n Photonique et de Nanostructures, Marcoussis, France"
],
[
"Harmand",
"J. -C.",
"",
"CNRS, Laboratoire de\n Photonique et de Nanostructures, Marcoussis, France"
],
[
"Patriarche",
"G.",
"",
"CNRS, Laboratoire de\n Photonique et de Nanostructures, Marcoussis, France"
]
] |
0706.0847 | Aaron Dotter | A. Dotter, B. Chaboyer, D. Jevremovic, E. Baron, J. W. Ferguson, A.
Sarajedini, J. Anderson | The ACS Survey of Galactic Globular Clusters. II. Stellar Evolution
Tracks, Isochrones, Luminosity Functions, and Synthetic Horizontal-Branch
Models | 46 pages, 12 figures, AJ in press; figures 11 and 12 are reduced in
size | Astron.J.134:376-390,2007 | 10.1086/517915 | null | astro-ph | null | The ACS Survey of Galactic Globular Clusters, an HST Treasury Project, will
deliver high quality, homogeneous photometry of 65 globular clusters. This
paper introduces a new collection of stellar evolution tracks and isochrones
suitable for analyzing the ACS Survey data. Stellar evolution models were
computed at [Fe/H]= -2.5, -2.0, -1.5, -1.0, -0.5, and 0; [alpha/Fe]= -0.2, 0,
0.2, 0.4, 0.6, and 0.8; and three initial He abundances for masses from 0.1 to
1.8 Msun and ages from 2 to 15 Gyr. Each isochrone spans a wide range in
luminosity from Mv~14 up to the tip of the red giant branch. These are
complemented by a set of He-burning tracks that extend from the zero age
horizontal branch to the onset of thermal pulsations on the asymptotic giant
branch. In addition, a set of computer programs are provided that make it
possible to interpolate the isochrones in [Fe/H], generate luminosity functions
from the isochrones, and create synthetic horizontal branch models. The tracks
and isochrones have been converted to the observational plane with two
different color-Teff transformations, one synthetic and one semi-empirical, in
ground-based B, V, and I, and F606W and F814W for both ACS-WFC and WFPC2
systems. All models and programs presented in this paper are available from
http://stellar.dartmouth.edu/~models/
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:46:23 GMT"
}
] | 2010-11-05T00:00:00 | [
[
"Dotter",
"A.",
""
],
[
"Chaboyer",
"B.",
""
],
[
"Jevremovic",
"D.",
""
],
[
"Baron",
"E.",
""
],
[
"Ferguson",
"J. W.",
""
],
[
"Sarajedini",
"A.",
""
],
[
"Anderson",
"J.",
""
]
] |
0706.0848 | Leonid A. Krivitsky | G. Brida, M.V. Chekhova, M. Genovese, L.A. Krivitsky | Generation of different Bell states within the SPDC phase-matching
bandwidth | submitted for publication | Physical Review A 76, 053807 (2007) | 10.1103/PhysRevA.76.053807 | null | quant-ph | null | We study the frequency-angular lineshape for a phase-matched nonlinear
process producing entangled states and show that there is a continuous variety
of maximally-entangled states generated for different mismatch values within
the natural bandwidth. Detailed considerations are made for two specific
methods of polarization entanglement preparation, based on type-II spontaneous
parametric down-conversion (SPDC) and on SPDC in two subsequent type-I crystals
producing orthogonally polarized photon pairs. It turns out that different Bell
states are produced at the center of the SPDC line and on its slopes,
corresponding to about half-maximum intensity level. These Bell states can be
filtered out by either frequency selection or angular selection, or both. Our
theoretical calculations are confirmed by a series of experiments, performed
for the two above-mentioned schemes of producing polarization-entangled photon
pairs and with two kinds of measurements: frequency-selective and
angular-selective.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:52:26 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Brida",
"G.",
""
],
[
"Chekhova",
"M. V.",
""
],
[
"Genovese",
"M.",
""
],
[
"Krivitsky",
"L. A.",
""
]
] |
0706.0849 | Stefan Hilbert | Stefan Hilbert, R. Benton Metcalf, and S. D. M. White | Imaging the Cosmic Matter Distribution using Gravitational Lensing of
Pregalactic HI | version accepted for publication in MNRAS (reduced-resolution
figures) | Mon.Not.Roy.Astron.Soc.382:1494,2007 | 10.1111/j.1365-2966.2007.12615.x | null | astro-ph | null | 21-cm emission from neutral hydrogen during and before the epoch of cosmic
reionisation is gravitationally lensed by material at all lower redshifts.
Low-frequency radio observations of this emission can be used to reconstruct
the projected mass distribution of foreground material, both light and dark. We
compare the potential imaging capabilities of such 21-cm lensing with those of
future galaxy lensing surveys. We use the Millennium Simulation to simulate
large-area maps of the lensing convergence with the noise, resolution and
redshift-weighting achievable with a variety of idealised observation
programmes. We find that the signal-to-noise of 21-cm lens maps can far exceed
that of any map made using galaxy lensing. If the irreducible noise limit can
be reached with a sufficiently large radio telescope, the projected convergence
map provides a high-fidelity image of the true matter distribution, allowing
the dark matter halos of individual galaxies to be viewed directly, and giving
a wealth of statistical and morphological information about the relative
distributions of mass and light. For instrumental designs like that planned for
the Square Kilometer Array (SKA), high-fidelity mass imaging may be possible
near the resolution limit of the core array of the telescope.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:56:51 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Feb 2008 14:47:41 GMT"
}
] | 2009-06-25T00:00:00 | [
[
"Hilbert",
"Stefan",
""
],
[
"Metcalf",
"R. Benton",
""
],
[
"White",
"S. D. M.",
""
]
] |
0706.0850 | Chuan Hung Chen | Chuan-Hung Chen, Chao-Qiang Geng | Unparticle phase effects | 19 pages, 9 figures, typos corrected, final version to appear in
Phys. Rev. D | Phys.Rev.D76:036007,2007 | 10.1103/PhysRevD.76.036007 | null | hep-ph hep-ex | null | Unparticles proposed by Georgi carry CP conserving phases in their
propagators. We demonstrate that these peculiar phases have an important impact
on CP violation. Without including the strong QCD phases, we study the
unparticle phase effects on the direct CP asymmetries in the exclusive decays
of $\bar B_d\to \pi^{+} \pi^{-}$ and $B\to \pi K$, in which the flavor changing
neutral currents are forbidden at tree level but induced by one-loop diagrams.
Interesting and consistent results comparing to the data are obtained. In
addition, we find that unparticles will significantly enhance the differential
branching ratio of $b\to s \ell^{+} \ell^{-}$ at the small invariant mass of
$\ell^{+} \ell^{-}$. The forward-backward asymmetries for $b\to s \ell^{+}
\ell^{-}$ due to unparticles are also explored.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:16:39 GMT"
},
{
"version": "v2",
"created": "Sun, 15 Jul 2007 07:02:39 GMT"
},
{
"version": "v3",
"created": "Thu, 30 Aug 2007 11:45:01 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Chen",
"Chuan-Hung",
""
],
[
"Geng",
"Chao-Qiang",
""
]
] |
0706.0851 | Kristian Harder | Kristian Harder (for the CDF and D0 Collaborations) | Electroweak measurements at the Tevatron | 6 pages, 2 figures, to appear in the proceedings of Les Rencontres de
Physique de La Vallee d'Aoste, La Thuile, 4-10 March 2007 | null | null | null | hep-ex | null | The increasing size of the data samples recorded by the CDF and DO
experiments at the Tevatron enables studies of a wide range of processes
involving the electroweak bosons W and Z. Single boson production is now looked
at in terms of differential cross sections such as rapidity or transverse
momentum dependence. Diboson production cross-sections are several orders of
magnitude smaller than single boson production cross-sections, but all
combinations Wgamma, Zgamma, WW and WZ have been observed. ZZ production is
expected at a rate just below the observation threshold with current data
sample sizes, but this channel is expected to be accessible to the Tevatron
experiments soon.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 15:58:29 GMT"
}
] | 2019-08-14T00:00:00 | [
[
"Harder",
"Kristian",
"",
"for the CDF and D0 Collaborations"
]
] |
0706.0852 | Jan Conrad Dr | Jan Conrad (representing the GLAST-LAT collaboration) | Searches for Particle Dark Matter with the GLAST Large Area Telescope | Contribution to Les Rencontres de Physique de la Valee d'Aoste, La
Thuile, Aosta Valley, Italy, March 2007 | Frascati Phys.Ser.44:65-72,2007 | null | null | astro-ph | null | The Large Area Telescope (LAT), one of two instruments on the Gamma-ray Large
Area Space Telescope (GLAST) mission, scheduled for launch by NASA in 2007, is
an imaging, wide field-of-view, high-energy gamma-ray telescope, covering the
approximate energy range from 20 MeV to more than 300 GeV. Annihilation of
Weakly Interacting Massive Particles (WIMP), predicted in many extensions of
the Standard Model of Particle Physics, may give rise to a signal in gamma-ray
spectra from many cosmic sources. In this contribution we give an overview of
the searches for WIMP Dark Matter performed by the GLAST-LAT collaboration.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:00:57 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Conrad",
"Jan",
"",
"representing the GLAST-LAT collaboration"
]
] |
0706.0853 | Robert Young | R. J. Young, S. J. Dewhurst, R. M. Stevenson, A. J. Shields, P.
Atkinson, K. Cooper, D. A. Ritchie | Controlling the polarisation correlation of photon pairs from a
charge-tuneable quantum dot | 3 figures | null | 10.1063/1.2754641 | null | quant-ph | null | Correlation between the rectilinear polarisations of the photons emitted from
the biexciton decay in a single quantum dot is investigated in a device which
allows the charge-state of the dot to be controlled. Optimising emission from
the neutral exciton states maximises the operating efficiency of the biexciton
decay. This is important for single dot applications such as a triggered source
of entangled photons. As the bias on the device is reduced correlation between
the two photons is found to fall dramatically as emission from the negatively
charged exciton becomes significant. Lifetime measurements demonstrate that
electronic spin-scattering is the likely cause.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:05:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Young",
"R. J.",
""
],
[
"Dewhurst",
"S. J.",
""
],
[
"Stevenson",
"R. M.",
""
],
[
"Shields",
"A. J.",
""
],
[
"Atkinson",
"P.",
""
],
[
"Cooper",
"K.",
""
],
[
"Ritchie",
"D. A.",
""
]
] |
0706.0854 | Nikolai Nikolov | Nikolai Nikolov, Pascal J. Thomas | On the zero set of the Kobayashi--Royden pseudometric of the spectral
unit ball | minor changes; to appear in Ann. Polon. Math | Ann. Pol. Math. 93 (2008), 53-68 | null | null | math.CV | null | Given $A\in\Omega_n,$ the $n^2$-dimensional spectral unit ball, we show that
$B$ is a "generalized" tangent vector at $A$ to an entire curve in $\Omega_n$
if and only if $B$ is in the tangent cone $C_A$ to the isospectral variety at
$A.$ In the case of $\Omega_3,$ the zero set of this metric is completely
described.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:05:39 GMT"
},
{
"version": "v2",
"created": "Sat, 15 Sep 2007 08:06:36 GMT"
},
{
"version": "v3",
"created": "Tue, 13 Nov 2007 10:05:16 GMT"
}
] | 2010-06-23T00:00:00 | [
[
"Nikolov",
"Nikolai",
""
],
[
"Thomas",
"Pascal J.",
""
]
] |
0706.0855 | Herbert Spohn | Herbert Spohn | On the Boltzmann Equation for Weakly Nonlinear Wave Equations | Boltzmann Proceedings, ESI, 15 pages,1 figure | null | null | null | math-ph math.MP | null | We explain how the kinetic theory of L. Boltzmann is applied to weakly
nonlinear wave equations.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:09:42 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Spohn",
"Herbert",
""
]
] |
0706.0856 | Massimo Ricotti | Massimo Ricotti, Andrew Pontzen, Matteo Viel | Is the Concentration of Dark Matter Halos at Virialization Universal ? | Accepted for Publication in the Astrophysical Journal Letter | null | 10.1086/520113 | null | astro-ph | null | Several recent studies suggest a correlation between dark matter halo mass
and the shape of the density profile. We re-analyze simulations from Ricotti
(2003) in which such a correlation was proposed. We use a standard analysis of
the halo density profiles and compare the old simulations to new ones performed
with Gadget2, including higher resolution runs. We confirm Ricotti's result
that, at virialization, the central log slopes alpha, at 5%-10% of the virial
radius are correlated with the halo mass and that the halo concentration is a
universal constant. Our results do not contradict the majority of published
papers: when using a split power law to fit the density profiles, due to the
alpha-concentration degeneracy, the fits are consistent with halos having a
universal shape with alpha=1 or 1.5 and concentrations that depend on the mass,
in agreement with results published elsewhere.
Recently, several groups have found no evidence for convergence of the inner
halo profile to a constant power law. The choice of a split power law
parameterization used in this letter is motivated by the need to compare our
results to previous ones and is formally valid because we are not able to
resolve regions where the slope of the fitting function reaches its asymptotic
constant value. Using a non-parameterized technique, we also show that the
density profiles of dwarf galaxies at z ~ 10 have a log slope shallower than
0.5 within 5% of the virial radius.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:13:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ricotti",
"Massimo",
""
],
[
"Pontzen",
"Andrew",
""
],
[
"Viel",
"Matteo",
""
]
] |
0706.0857 | Antonio Padilla | Christos Charmousis, Ruth Gregory and Antonio Padilla | Stealth Acceleration and Modified Gravity | 32 pages, 5 figures | JCAP 0710:006,2007 | 10.1088/1475-7516/2007/10/006 | null | hep-th astro-ph hep-ph | null | We show how to construct consistent braneworld models which exhibit late time
acceleration. Unlike self-acceleration, which has a de Sitter vacuum state, our
models have the standard Minkowski vacuum and accelerate only in the presence
of matter, which we dub ``stealth-acceleration''. We use an effective action
for the brane which includes an induced gravity term, and allow for an
asymmetric set-up. We study the linear stability of flat brane vacua and find
the regions of parameter space where the set-up is stable. The 4-dimensional
graviton is only quasi-localised in this set-up and as a result gravity is
modified at late times. One of the two regions is strongly coupled and the
scalar mode is eaten up by an extra symmetry that arises in this limit. Having
filtered the well-defined theories we then focus on their cosmology. When the
graviton is quasi-localised we find two main examples of acceleration. In each
case, we provide an illustrative model and compare it to LambdaCDM.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:16:38 GMT"
}
] | 2009-04-17T00:00:00 | [
[
"Charmousis",
"Christos",
""
],
[
"Gregory",
"Ruth",
""
],
[
"Padilla",
"Antonio",
""
]
] |
0706.0858 | Pawe{\l} Machnikowski | P. Machnikowski | Two-photon coherent polarization flipping of confined excitons | To be presented at the school Jaszowiec 2007 | Acta Physica Polonica A 112 (2007) 289 | null | null | cond-mat.mes-hall | null | A two-photon process leading to coherent transitions between the two
circularly polarized exciton states in a quantum dot is studied. It is shown
that optical flipping of the exciton polarization is possible with picosecond
laser pulses. The process is closely related to two-photon Rabi oscillations of
a biexciton but it is much more stable against shifts of the laser frequency.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:21:19 GMT"
}
] | 2007-10-24T00:00:00 | [
[
"Machnikowski",
"P.",
""
]
] |
0706.0859 | Marco Boggi | M. Boggi, P. Lochak | Profinite complexes of curves, their automorphisms and anabelian
properties of moduli stacks of curves | Superseded by arXiv:2004.04135 and hal-02992317 | null | null | null | math.AG math.NT | null | Let ${\cal M}_{g,[n]}$, for $2g-2+n>0$, be the D-M moduli stack of smooth
curves of genus $g$ labeled by $n$ unordered distinct points. The main result
of the paper is that a finite, connected \'etale cover ${\cal M}^\l$ of ${\cal
M}_{g,[n]}$, defined over a sub-$p$-adic field $k$, is "almost" anabelian in
the sense conjectured by Grothendieck for curves and their moduli spaces.
The precise result is the following. Let $\pi_1({\cal M}^\l_{\ol{k}})$ be the
geometric algebraic fundamental group of ${\cal M}^\l$ and let
${Out}^*(\pi_1({\cal M}^\l_{\ol{k}}))$ be the group of its exterior
automorphisms which preserve the conjugacy classes of elements corresponding to
simple loops around the Deligne-Mumford boundary of ${\cal M}^\l$ (this is the
"$\ast$-condition" motivating the "almost" above). Let us denote by
${Out}^*_{G_k}(\pi_1({\cal M}^\l_{\ol{k}}))$ the subgroup consisting of
elements which commute with the natural action of the absolute Galois group
$G_k$ of $k$. Let us assume, moreover, that the generic point of the D-M stack
${\cal M}^\l$ has a trivial automorphisms group. Then, there is a natural
isomorphism: $${Aut}_k({\cal M}^\l)\cong{Out}^*_{G_k}(\pi_1({\cal
M}^\l_{\ol{k}})).$$ This partially extends to moduli spaces of curves the
anabelian properties proved by Mochizuki for hyperbolic curves over
sub-$p$-adic fields.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:22:37 GMT"
},
{
"version": "v2",
"created": "Mon, 24 Jan 2011 19:17:00 GMT"
},
{
"version": "v3",
"created": "Tue, 23 May 2023 14:11:03 GMT"
}
] | 2023-05-24T00:00:00 | [
[
"Boggi",
"M.",
""
],
[
"Lochak",
"P.",
""
]
] |
0706.0860 | Guy Steve Muanza | G.S. Muanza (IPN Lyon, CNRS-In2p3, Lyon University) | Non SUSY Searches at the Tevatron | 4 pages, 6 figures, Rencontres de Moriond 2007 "QCD and High Energy
Hadronic Interactions" | null | null | D0CONF-5415 | hep-ex | null | Recent searches for non-SUSY exotics in $p\bar{p}$ collisions at a
center-of-mass energy of 1.96 TeV at the Tevatron Run II are reported. The
emphasis is put on the results of model-driven analyses which were updated to
the full Run IIA datasets corresponding to integrated luminosities of about 1
$fb^{-1}$.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:25:18 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Muanza",
"G. S.",
"",
"IPN Lyon, CNRS-In2p3, Lyon University"
]
] |
0706.0861 | Pawe{\l} Machnikowski | A. Sitek and P. Machnikowski | Four wave mixing spectroscopy of quantum dot molecules | Presented at the school Jaszowiec 2007. Corrected figures and some
other minor improvements | Acta Physica Polonica A 112 (2007) 167 | null | null | cond-mat.mes-hall | null | We study theoretically the nonlinear four wave mixing (FWM) response of an
ensemble of coupled pairs of quantum dots (quantum dot molecules). We discuss
the shape of the FWM echo signal depending on the parameters of the ensemble:
the statistics of transition energies and the degree of size correlations
between the dots forming the molecules.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:27:28 GMT"
},
{
"version": "v2",
"created": "Wed, 24 Oct 2007 09:21:32 GMT"
}
] | 2007-10-24T00:00:00 | [
[
"Sitek",
"A.",
""
],
[
"Machnikowski",
"P.",
""
]
] |
0706.0862 | Pawe{\l} Machnikowski | E. Rozbicki and P. Machnikowski | Phonon-assisted excitation transfer in quantum dot molecules | To be presented at the school Jaszowiec 2007 | Acta Physica Polonica A 112 (2007) 197 | null | null | cond-mat.mes-hall | null | We derive a quantum-kinetic description of phonon-assisted F{\"o}rster
transfer between two coupled quantum dots (a quantum dot molecule). We show
that the exciton state decays to the ground state of the QDM via a combination
of the Rabi rotation and exponential decay. For moderately spaced dots this
process takes place on a picosecond time scale.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:33:05 GMT"
}
] | 2007-10-24T00:00:00 | [
[
"Rozbicki",
"E.",
""
],
[
"Machnikowski",
"P.",
""
]
] |
0706.0863 | De-en Jiang | De-en Jiang, Bobby G. Sumpter, Sheng Dai | First principles study of magnetism in nanographenes | 20 pages, 4 figures | J. Chem. Phys. 127, 124703 (2007) (5 pages) | 10.1063/1.2770722 | null | physics.chem-ph | null | Magnetism in nanographenes (also know as polycyclic aromatic hydrocarbons, or
PAHs) are studied with first principles density functional calculations. We
find that an antiferromagnetic (AFM) phase appears as the PAH reaches a certain
size. This AFM phase in PAHs has the same origin as the one in infinitely long
zigzag-edged graphene nanoribbons, namely, from the localized electronic state
at the zigzag edge. The smallest PAH still having an AFM ground state is
identified. With increased length of the zigzag edge, PAHs approach an
infinitely long ribbon in terms of (1) the energetic ordering and difference
among the AFM, ferromagnetic (FM), and nonmagnetic (NM) phases and (2) the
average local magnetic moment at the zigzag edges. These PAHs serve as ideal
targets for chemical synthesis of nanographenes that possess magnetic
properties. Moreover, our calculations support the interpretation that
experimentally observed magnetism in activated carbon fibers originates from
the zigzag edges of the nanographenes.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 19:16:40 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Jul 2007 15:01:53 GMT"
}
] | 2007-09-27T00:00:00 | [
[
"Jiang",
"De-en",
""
],
[
"Sumpter",
"Bobby G.",
""
],
[
"Dai",
"Sheng",
""
]
] |
0706.0864 | Massimo Ricotti | Massimo Ricotti | Bondi accretion in the early universe | 10 pages, 6 figures, ApJ in press (Apj, 662, 53) | Astrophys.J.662:53-61,2007 | 10.1086/516562 | null | astro-ph | null | This paper presents a study of quasi-steady spherical accretion in the early
Universe, before the formation of the first stars and galaxies. The main
motivation is to derive the basic formulas that will be used in a companion
paper to calculate the accretion luminosity of primordial black holes and their
effect on the cosmic ionization history.
The following cosmological effects are investigated: the coupling of the gas
to the CMB photon fluid (i.e., Compton drag), Hubble expansion, and the growth
of the dark matter halo seeded by the gravitational potential of the central
point mass. The gas equations of motion are solved assuming either a polytropic
or an isothermal equation of state. We consider the cases in which the
accreting object is a point mass or a spherical dark matter halo with power-law
density profile, as predicted by the theory of "secondary infall''. Analytical
solutions for the sonic radius and fitting formulas for the accretion rate are
provided.
Different accretion regimes exist depending on the mass of the accreting
object. If the black hole mass is smaller than 50-100 Msun, gas accretion is
unaffected by Compton drag. A point mass and an extended dark halo of equal
mass accrete at the same rate if M>5000 Msun, while smaller mass dark halos
accrete less efficiently than the equivalent point mass. For masses M>3 x 10^4
Msun, the viscous term due to the Hubble expansion becomes important and the
assumption of quasi-steady flow fails. Hence, the steady Bondi solutions
transition to the time-dependent self-similar solutions for "cold cosmological
infall".
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:13:02 GMT"
}
] | 2010-11-05T00:00:00 | [
[
"Ricotti",
"Massimo",
""
]
] |
0706.0865 | Juan Ponciano | J. A. Ponciano, N. N. Scoccola | Skyrmions in the presence of isospin chemical potential | 8 pages, 2 figures | Phys.Lett.B659:551-554,2008 | 10.1016/j.physletb.2007.11.047 | null | hep-ph | null | We analyze the existence of localized finite energy topological excitations
on top of the perturbative pion vacuum within the Skyrme model at finite
isospin chemical potential and finite pion mass. We show that there is a
critical isospin chemical potential $\mu_I^c$ above which such solutions cease
to exist. We find that $\mu_I^c$ is closely related to the value of the pion
mass. In particular for vanishing pion mass we obtain $\mu_I^c=0$ in
contradiction with some results recently reported in the literature. We also
find that below $\mui^c$ the skyrmion mass and baryon radius show, at least for
the case of the hedgehog ansatz, only a mild dependence on the isospin chemical
potential.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:48:10 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ponciano",
"J. A.",
""
],
[
"Scoccola",
"N. N.",
""
]
] |
0706.0866 | Ian Appelbaum | Biqin Huang (1), Douwe J. Monsma (2), Ian Appelbaum (1) ((1)
University of Delaware, (2) Cambridge Nanotech) | Coherent spin transport through a 350-micron-thick Silicon wafer | Accepted in PRL | Phys. Rev. Lett. 99, 177209 (2007) | 10.1103/PhysRevLett.99.177209 | null | cond-mat.mtrl-sci cond-mat.other | null | We use all-electrical methods to inject, transport, and detect spin-polarized
electrons vertically through a 350-micron-thick undoped single-crystal silicon
wafer. Spin precession measurements in a perpendicular magnetic field at
different accelerating electric fields reveal high spin coherence with at least
13pi precession angles. The magnetic-field spacing of precession extrema are
used to determine the injector-to-detector electron transit time. These transit
time values are associated with output magnetocurrent changes (from in-plane
spin-valve measurements), which are proportional to final spin polarization.
Fitting the results to a simple exponential spin-decay model yields a
conduction electron spin lifetime (T1) lower bound in silicon of over 500ns at
60K.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 16:49:57 GMT"
},
{
"version": "v2",
"created": "Wed, 8 Aug 2007 17:21:18 GMT"
},
{
"version": "v3",
"created": "Fri, 14 Sep 2007 15:06:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Huang",
"Biqin",
""
],
[
"Monsma",
"Douwe J.",
""
],
[
"Appelbaum",
"Ian",
""
]
] |
0706.0867 | John D. Monnier | John D. Monnier (1), M. Zhao (1), E. Pedretti (2), N. Thureau (3), M.
Ireland (4), P. Muirhead (5), J.-P. Berger (6), R. Millan-Gabet (7), G. Van
Belle (7), T. ten Brummelaar (8), H. McAlister (8), S. Ridgway (9), N. Turner
(8), L. Sturmann (8), J. Sturmann (8), D. Berger (1) ((1) U. Michigan, (2)
St. Andrews, (3) Cambridge, (4) Caltech, (5) Cornell, (6) Grenoble, (7)
Michelson Science Center, (8) Georgia State -- CHARA, (9) NOAO) | Imaging the Surface of Altair | 24 pages. to appear in Science. includes Report and Supplemental
Online Materials. Accompanying animation can be found at
http://www.astro.lsa.umich.edu/~monnier/Altair2007/altair2007.html | null | 10.1126/science.1143205 | null | astro-ph | null | Spatially resolving the surfaces of nearby stars promises to advance our
knowledge of stellar physics. Using optical long-baseline interferometry, we
present here a near-infrared image of the rapidly rotating hot star Altair with
<1 milliarcsecond resolution. The image clearly reveals the strong effect of
gravity darkening on the highly-distorted stellar photosphere. Standard models
for a uniformly rotating star can not explain our results, requiring
differential rotation, alternative gravity darkening laws, or both.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:04:47 GMT"
},
{
"version": "v2",
"created": "Thu, 7 Jun 2007 14:41:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Monnier",
"John D.",
""
],
[
"Zhao",
"M.",
""
],
[
"Pedretti",
"E.",
""
],
[
"Thureau",
"N.",
""
],
[
"Ireland",
"M.",
""
],
[
"Muirhead",
"P.",
""
],
[
"Berger",
"J. -P.",
""
],
[
"Millan-Gabet",
"R.",
""
],
[
"Van Belle",
"G.",
""
],
[
"Brummelaar",
"T. ten",
""
],
[
"McAlister",
"H.",
""
],
[
"Ridgway",
"S.",
""
],
[
"Turner",
"N.",
""
],
[
"Sturmann",
"L.",
""
],
[
"Sturmann",
"J.",
""
],
[
"Berger",
"D.",
""
]
] |
0706.0868 | Simone Montangero | Matteo Rizzi, Simone Montangero, Guifre' Vidal | Simulation of time evolution with the MERA | final version with data improvement (precision and size), 4.1 pages,
4 figures + extra on XY | Phys. Rev. A 77, 052328 (2008) | 10.1103/PhysRevA.77.052328 | null | quant-ph cond-mat.other | null | We describe an algorithm to simulate time evolution using the Multi-scale
Entanglement Renormalization Ansatz (MERA) and test it by studying a critical
Ising chain with periodic boundary conditions and with up to L ~ 10^6 quantum
spins. The cost of a simulation, which scales as L log(L), is reduced to log(L)
when the system is invariant under translations. By simulating an evolution in
imaginary time, we compute the ground state of the system. The errors in the
ground state energy display no evident dependence on the system size. The
algorithm can be extended to lattice systems in higher spatial dimensions.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:13:25 GMT"
},
{
"version": "v2",
"created": "Thu, 24 Apr 2008 10:33:39 GMT"
}
] | 2008-06-09T00:00:00 | [
[
"Rizzi",
"Matteo",
""
],
[
"Montangero",
"Simone",
""
],
[
"Vidal",
"Guifre'",
""
]
] |
0706.0869 | Edward Aboufadel | Edward Aboufadel, Timothy Armstrong, Elizabeth Smietana | Position Coding | 14 pages, 7 figures | null | null | null | cs.IT math.CO math.IT | null | A position coding pattern is an array of symbols in which subarrays of a
certain fixed size appear at most once. So, each subarray uniquely identifies a
location in the larger array, which means there is a bijection of some sort
from this set of subarrays to a set of coordinates. The key to Fly Pentop
Computer paper and other examples of position codes is a method to read the
subarray and then convert it to coordinates. Position coding makes use of ideas
from discrete mathematics and number theory. In this paper, we will describe
the underlying mathematics of two position codes, one being the Anoto code that
is the basis of "Fly paper". Then, we will present two new codes, one which
uses binary wavelets as part of the bijection.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:09:21 GMT"
}
] | 2007-07-13T00:00:00 | [
[
"Aboufadel",
"Edward",
""
],
[
"Armstrong",
"Timothy",
""
],
[
"Smietana",
"Elizabeth",
""
]
] |
0706.0870 | Nachi Gupta | Nachi Gupta, Raphael Hauser, and Neil F. Johnson | Inferring the Composition of a Trader Population in a Financial Market | 15 pages, 2 figures, to appear as a chapter in "Econophysics and
Sociophysics of Markets and Networks", Springer-Verlag | null | 10.1007/978-88-470-0665-2_7 | null | cs.CE nlin.AO | null | We discuss a method for predicting financial movements and finding pockets of
predictability in the price-series, which is built around inferring the
heterogeneity of trading strategies in a multi-agent trader population. This
work explores extensions to our previous framework (arXiv:physics/0506134).
Here we allow for more intelligent agents possessing a richer strategy set, and
we no longer constrain the estimate for the heterogeneity of the agents to a
probability space. We also introduce a scheme which allows the incorporation of
models with a wide variety of agent types, and discuss a mechanism for the
removal of bias from relevant parameters.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:29:42 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Gupta",
"Nachi",
""
],
[
"Hauser",
"Raphael",
""
],
[
"Johnson",
"Neil F.",
""
]
] |
0706.0871 | Vijayashankar Ramareddy | I. Dana, V. Ramareddy, I. Talukdar, G. S. Summy | Experimental Realization of Quantum-Resonance Ratchets | Accepted for publication in Physical Review Letters (November 2007) | Physical Review Letters 100, 024103 (2008) | 10.1103/PhysRevLett.100.024103 | null | physics.atom-ph nlin.CD | null | Quantum-resonance ratchets associated with the periodically kicked particle
are experimentally realized for the first time. This is achieved by using a
Bose-Einstein condensate exposed to a pulsed standing light wave and prepared
in an initial state differing from the usual plane wave. Both the standing-wave
potential and the initial state have a point symmetry around some center and
the ratchet arises from the non-coincidence of the two centers. The dependence
of the directed quantum transport on the quasimomentum is studied. A detailed
theoretical analysis is used to explain the experimental results.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:31:30 GMT"
},
{
"version": "v2",
"created": "Wed, 5 Sep 2007 20:59:06 GMT"
},
{
"version": "v3",
"created": "Tue, 27 Nov 2007 06:49:57 GMT"
}
] | 2008-01-20T00:00:00 | [
[
"Dana",
"I.",
""
],
[
"Ramareddy",
"V.",
""
],
[
"Talukdar",
"I.",
""
],
[
"Summy",
"G. S.",
""
]
] |
0706.0872 | Nadav Yoran | Nadav Yoran and Anthony J. Short | Classical simulability and the significance of modular exponentiation in
Shor's algorithm | 4 pages, 2 figures | Phys. Rev. A 76, 060302(R) (2007). | 10.1103/PhysRevA.76.060302 | null | quant-ph | null | We show that a classical algorithm efficiently simulating the modular
exponentiation circuit, for certain product state input and with measurements
in a general product state basis at the output, can efficiently simulate Shor's
factoring algorithm. This is done by using the notion of the semi-classical
Fourier transform due to Griffith and Niu, and further discussed in the context
of Shor's algorithm by Browne.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:33:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Yoran",
"Nadav",
""
],
[
"Short",
"Anthony J.",
""
]
] |
0706.0873 | Nicolas Saintier | Nicolas Saintier | Shape derivative of the first eigenvalue of the 1-Laplacian | null | null | null | null | math.AP | null | We compute the shape derivative of the first eigenvalue of the 1-Laplacian.
As an application, we find that a ball is critical among all volume-preserving
deformations.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:37:17 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Saintier",
"Nicolas",
""
]
] |
0706.0874 | Olivier Pfister | Daruo Xie, Matthew Pysher, Jietai Jing, and Olivier Pfister | Enhanced optical communication and broadband sub-shot-noise
interferometry with a stable free-running periodically-poled-KTiOPO4 squeezer | 9 pages, 4 figs, submitted for publication | JOSA B 24, 2702 (2007) | 10.1364/JOSAB.24.002702 | null | quant-ph | null | An intrinsically stable type-I optical parametric oscillator was built with a
periodically poled KTiOPO4 (PPKTP) crystal to generate a stable bright,
continuous-wave, broadband phase-squeezed beam. A 3.2 dB sensitivity
enhancement of optical interferometry was demonstrated on weak electrooptic
modulation signals within a 20 MHz squeezing bandwidth. This also realized a
channel capacity increase beyond that of coherent optical communication.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:44:56 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Xie",
"Daruo",
""
],
[
"Pysher",
"Matthew",
""
],
[
"Jing",
"Jietai",
""
],
[
"Pfister",
"Olivier",
""
]
] |
0706.0875 | Mordehai Milgrom | Mordehai Milgrom | MOND and the mass discrepancies in tidal dwarf galaxies | 9 pages, 1 figure. Changed to agree with the version to be published
in Astrophys. J. Lett | Astrophys. J. Lett. 667, L45 (2007) | 10.1086/522049 | null | astro-ph | null | I consider in light of MOND the three debris galaxies discussed recently by
Bournaud et al.. These exhibit mass discrepancies of a factor of a few within
several scale lengths of the visible galaxy, which, arguably, flies in the face
of the cold dark matter paradigm. I show here that the rotational velocities
predicted by MOND agree well with the observed velocities for each of the three
galaxies, with only the observed baryonic matter as the source of gravity.
There is thus no need to invoke a new form of baryonic, yet-undetected matter
that dominates the disc of spiral galaxies, as advocated by Bournaud et al. I
argue on other grounds that the presence of such ubiquitous disc dark matter,
in addition to cold dark matter, is not likely.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:08:51 GMT"
},
{
"version": "v2",
"created": "Sun, 9 Sep 2007 10:50:21 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Milgrom",
"Mordehai",
""
]
] |
0706.0876 | Danny Fan | Nassif Ghoussoub and Abbas Moameni | Schrodinger equations and Hamiltonian systems of PDEs with selfdual
boundary conditions | 36 pages. Updated versions --if any-- of this author's papers can be
downloaded at http://www.birs.ca/~nassif | null | null | null | math.AP | null | Selfdual variational calculus is further refined and used to address
questions of existence of local and global solutions for various parabolic
semi-linear equations, Hamiltonian systems of PDEs, as well as certain
nonlinear Schrodinger evolutions. This allows for the resolution of such
equations under general time boundary conditions which include the more
traditional ones such as initial value problems, periodic and anti-periodic
orbits, but also yield new ones such as "periodic orbits up to an isometry" for
evolution equations that may not have periodic solutions. In the process, we
introduce a method for perturbing selfdual functionals in order to induce
coercivity and compactness, while keeping the system selfdual.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:17:28 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Ghoussoub",
"Nassif",
""
],
[
"Moameni",
"Abbas",
""
]
] |
0706.0877 | Marc Ribo | J.M. Paredes, M. Ribo, V. Bosch-Ramon, J.R. West, Y.M. Butt, D.F.
Torres, J. Marti | Chandra Observations of the Gamma-ray Binary LSI+61303: Extended X-ray
Structure? | 4 pages, 3 figures. Accepted for publication in ApJ Letters | Astrophys.J.664:L39-L42,2007 | 10.1086/520674 | null | astro-ph | null | We present a 50 ks observation of the gamma-ray binary LSI+61303 carried out
with the ACIS-I array aboard the Chandra X-ray Observatory. This is the highest
resolution X-ray observation of the source conducted so far. Possible evidence
of an extended structure at a distance between 5 and 12 arcsec towards the
North of LSI+61303 have been found at a significance level of 3.2 sigma. The
asymmetry of the extended emission excludes an interpretation in the context of
a dust-scattered halo, suggesting an intrinsic nature. On the other hand, while
the obtained source flux, of F_{0.3-10 keV}=7.1^{+1.8}_{-1.4} x 10^{-12}
ergs/cm^2/s, and hydrogen column density, N_{H}=0.70+/-0.06 x 10^{22} cm^{-2},
are compatible with previous results, the photon index Gamma=1.25+/-0.09 is the
hardest ever found. In light of these new results, we briefly discuss the
physics behind the X-ray emission, the location of the emitter, and the
possible origin of the extended emission ~0.1 pc away from LSI+61303.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:57:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Paredes",
"J. M.",
""
],
[
"Ribo",
"M.",
""
],
[
"Bosch-Ramon",
"V.",
""
],
[
"West",
"J. R.",
""
],
[
"Butt",
"Y. M.",
""
],
[
"Torres",
"D. F.",
""
],
[
"Marti",
"J.",
""
]
] |
0706.0878 | Marcos Jardim | Marcos Jardim and Rafael F. Leao | On the spectrum of the twisted Dolbeault Laplacian over K\"ahler
manifolds | 14 pages. Completely revised: estimates corrected and shown to be
sharp | Journal of Mathematical Physics 50 (2009), 063513 | 10.1063/1.3133944 | null | math.DG | null | We use Dirac operator techniques to a establish sharp lower bound for the
first eigenvalue of the Dolbeault Laplacian twisted by Hermitian-Einstein
connections on vector bundles of negative degree over compact K\"ahler
manifolds.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 17:59:47 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Jun 2008 14:13:51 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Jardim",
"Marcos",
""
],
[
"Leao",
"Rafael F.",
""
]
] |
0706.0879 | Adrian Roellin | Adrian R\"ollin | On the optimality of Stein factors | final version | In Probability Approximations and Beyond, Lecture Notes in
Statistics 205, Springer 2012, pg 61-72 | null | null | math.PR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The application of Stein's method for distributional approximation often
involves so called Stein factors (also called 'magic factors') in the bound of
the solutions to Stein equations. However, in some cases these factors contain
additional (undesirable) logarithmic terms. It has been shown for many Stein
factors that the known bounds are sharp and thus that these additional
logarithmic terms cannot be avoided in general. However, no probabilistic
examples have appeared in the literature that would show that these terms in
the Stein factors are not just unavoidable artefacts, but that they are there
for a good reason. In this article we close this gap by constructing such
examples. This also leads to a new interpretation of the solutions to Stein
equations.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:02:06 GMT"
},
{
"version": "v2",
"created": "Tue, 26 Jun 2007 13:17:34 GMT"
},
{
"version": "v3",
"created": "Wed, 12 Jun 2013 01:32:09 GMT"
}
] | 2013-06-13T00:00:00 | [
[
"Röllin",
"Adrian",
""
]
] |
0706.0880 | Alvaro de Rujula | Shlomo Dado, Arnon Dar and Alvaro De Rujula | On the X-Ray emission of Gamma Ray Bursts | 45 pages, 8 (multiple) figures | null | null | null | astro-ph | null | Recent data gathered and triggered by the SWIFT satellite have greatly
improved our knowledge of long-duration gamma ray bursts (GRBs) and X-ray
flashes (XRFs). This is particularly the case for the X-ray data at all times.
We show that the entire X-ray observations are in excellent agreement with the
predictions of the `cannonball' model of GRBs and XRFs, which are based on
simple physics and were published long before the launch of SWIFT. Two
mechanisms underlie these predictions: inverse Compton scattering and
synchrotron radiation, generally dominant at early and late times,
respectively. The former mechanism provides a unified description of the
gamma-ray peaks, X-ray flares and even the optical `humps' seen in some
favourable cases; i.e. their very different durations, fluxes and peak-times
are related precisely as predicted. The observed smooth or bumpy fast decay of
the X-ray light curve is correctly described case-by-case, in minute detail.
The `canonical' X-ray plateau, as well as the subsequent gradual steepening of
the afterglow to an asymptotic power-law decay, are as foretold. So are the
chromatic and achromatic properties of the light-curves.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 19:25:35 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Dado",
"Shlomo",
""
],
[
"Dar",
"Arnon",
""
],
[
"De Rujula",
"Alvaro",
""
]
] |
0706.0881 | Yuri Zelikov | E. Ostrovsky, Y. Zelikov | Adaptive Optimal Nonparametric Regression and Density Estimation Based
on Fourier-Legendre Expansion | null | null | null | null | math.ST math.SP stat.TH | null | Motivated by finance and technical applications, the objective of this paper
is to consider adaptive estimation of regression and density distribution based
on Fourier-Legendre expansion, and construction of confidence intervals - also
adaptive. The estimators are asymptotically optimal and adaptive in the sense
that they can adapt to unknown smoothness.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:03:02 GMT"
}
] | 2011-02-19T00:00:00 | [
[
"Ostrovsky",
"E.",
""
],
[
"Zelikov",
"Y.",
""
]
] |
0706.0882 | Alexander Moiseev | Alexander A.Moiseev, Jonathan F.Ormes, and Igor V.Moskalenko | Measuring 10-1000 GeV Cosmic Ray Electrons with GLAST/LAT | 5 pages, 5 figures, 1 table | Proc. 30th ICRC (Merida), 2, 449-452 (2007) | null | null | astro-ph | null | We present here the capabilities of the GLAST Large Area Telescope to detect
cosmic ray high-energy (HE) electrons in the energy range from 10 GeV to 1 TeV.
We also discuss the science topics that can be investigated with HE electron
data and quantify the results with LAT instrument simulations. The science
topics include CR propagation, calibration of the IC gamma-ray model, testing
hypotheses regarding the origin of HE energy cosmic-ray electrons, searching
for any signature of Kaluza Klein Dark Matter annihilation, and measuring the
HE electron anisotropy. We expect to detect ~ 107 electrons above 20 GeV per
year of LAT operation.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:07:28 GMT"
}
] | 2009-02-25T00:00:00 | [
[
"Moiseev",
"Alexander A.",
""
],
[
"Ormes",
"Jonathan F.",
""
],
[
"Moskalenko",
"Igor V.",
""
]
] |
0706.0883 | Marcos Jardim | Marcos Jardim and Rafael F. Leao | Survey on eigenvalues of the Dirac operator and geometric structures | 19 pages, To appear in International Mathematical Forum (2008) | null | null | null | math.DG | null | We give a survey of results relating the restricted holonomy of a Riemannian
spin manifold with lower bounds on the spectrum of its Dirac operator, giving a
new proof of a result originally due to Kirchberg.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:10:03 GMT"
}
] | 2007-11-12T00:00:00 | [
[
"Jardim",
"Marcos",
""
],
[
"Leao",
"Rafael F.",
""
]
] |
0706.0884 | Alessandro Torrielli | Sanefumi Moriyama and Alessandro Torrielli | A Yangian Double for the AdS/CFT Classical r-matrix | 18 pages, no figures, LaTeX. v2: references added and minor changes | JHEP 0706:083,2007 | 10.1088/1126-6708/2007/06/083 | MIT-CTP-3843 | hep-th | null | We express the classical r-matrix of AdS/CFT in terms of tensor products
involving an infinite family of generators, which takes a form suggestive of
the universal expression obtained from a Yangian double. This should provide an
insight into the structure of the infinite dimensional symmetry algebra
underlying the integrability of the model, and give a clue to the construction
of its universal R-matrix. We derive the commutation relations under which the
algebra of these new generators close.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:11:44 GMT"
},
{
"version": "v2",
"created": "Thu, 14 Jun 2007 18:35:01 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Moriyama",
"Sanefumi",
""
],
[
"Torrielli",
"Alessandro",
""
]
] |
0706.0885 | Richard MacKenzie | R. MacKenzie, A. Morin-Duchesne, H. Paquette and J. Pinel | Validity of the Adiabatic Approximation | 4 pages, 1 figure | Phys. Rev. A 76, 044102 (2007) | 10.1103/PhysRevA.76.044102 | UdeM-GPP-TH-07-159 | quant-ph | null | We analyze the validity of the adiabatic approximation, and in particular the
reliability of what has been called the "standard criterion" for validity of
this approximation. Recently, this criterion has been found to be insufficient.
We will argue that the criterion is sufficient only when it agrees with the
intuitive notion of slowness of evolution of the Hamiltonian. However, it can
be insufficient in cases where the Hamiltonian varies rapidly but only by a
small amount. We also emphasize the distinction between the adiabatic {\em
theorem} and the adiabatic {\em approximation}, two quite different although
closely related ideas.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:29:03 GMT"
}
] | 2007-10-30T00:00:00 | [
[
"MacKenzie",
"R.",
""
],
[
"Morin-Duchesne",
"A.",
""
],
[
"Paquette",
"H.",
""
],
[
"Pinel",
"J.",
""
]
] |
0706.0886 | Konstantin Doubrovinsky L | K. Doubrovinski, M. Herrmann | Stability of Localized Patterns in Neural Fields | null | null | null | null | nlin.AO | null | We investigate two-dimensional neural fields as a model of the dynamics of
macroscopic activations in a cortex-like neural system. While the
one-dimensional case has been treated comprehensively by Amari 30 years ago,
two-dimensional neural fields are much less understood. We derive conditions
for the stability for the main classes of localized solutions of the neural
field equation and study their behavior beyond parameter-controlled
destabilization. We show that a slight modification of original model yields an
equation whose stationary states are guaranteed to satisfy the original problem
and numerically demonstrate that it admits localized non-circular solutions.
Generically, however, only periodic spatial tessellations emerge upon
destabilization of rotationally-invariant solutions.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:29:05 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Doubrovinski",
"K.",
""
],
[
"Herrmann",
"M.",
""
]
] |
0706.0887 | Nceba Mhlahlo | N. Mhlahlo, D.A.H. Buckley, V. Dhillon, S. Potter, B. Warner and P.
Woudt | Outbursts of EX Hydrae Revisited | 12 pages, 14 figures, 1 table. Figures 6, 7, 8 and 11 at low
resolution. Paper accepted by the Monthly Notices of the Royal Astronomical
Society | null | 10.1111/j.1365-2966.2007.12077.x | null | astro-ph | null | We present optical spectroscopy of EX Hya during its 1991 outburst. This
outburst is characterised by strong irradiation of the front face of the
secondary star by the white dwarf, an overflowing stream which is seen strongly
in HeII and by a dip in the light curves, which extends from 0.1-0.6 in the
binary and spin phases. Strong irradiation of the accretion curtain and that of
the inner regions of the disc led to strong emission of HeII and to the
suppression of the Hg and Hb emission.
Disc overflow was observed in quiescence in earlier studies, where the
overflow stream material was modulated at high velocities close to 1000 km/s.
In outburst, the overflowing material is modulated at even higher velocities
(~1500 km/s). These are streaming velocities down the field lines close to the
white dwarf. Evidence for material collecting near the outer edge of the disc
and corotating with the accretion curtain was observed. In decline, this
material and the accretion curtain obscured almost all the emission near binary
phase 0.4, causing a dip. The dip minimum nearly corresponds with spin pulse
minimum. This has provided additional evidence for an extended accretion
curtain, and for the corotation of material with the accretion curtain at the
outer edge of the disc. From these observations we suggest that a mechanism
similar to that of Spruit & Taam, where outbursts result due to the storage and
release of matter outside the magnetosphere, triggers the outbursts of EX Hya.
This is followed by the irradiation of the secondary star due to accretion
induced radiation.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:34:37 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Mhlahlo",
"N.",
""
],
[
"Buckley",
"D. A. H.",
""
],
[
"Dhillon",
"V.",
""
],
[
"Potter",
"S.",
""
],
[
"Warner",
"B.",
""
],
[
"Woudt",
"P.",
""
]
] |
0706.0888 | Beniamino Cappelletti Montano | Beniamino Cappelletti Montano | Some remarks on the generalized Tanaka-Webster connection of a contact
metric manifold | To appear on Rocky Mountain J. Math | Rocky Mountain J. Math. 40 (2010), 1009-1037 | 10.1216/RMJ-2010-40-3-1009 | null | math.DG | null | We find necessary and sufficient conditions for the bi-Legendrian connection
$\nabla$ associated to a bi-Legendrian structure $(\cal F,\cal G)$ on a contact
metric manifold $(M,\phi,\xi,\eta,g)$ being a metric connection and then we
give conditions ensuring that $\nabla$ coincides with the (generalized)
Tanaka-Webster connection of $(M,\phi,\xi,\eta,g)$. Using these results, we
give some interpretations of the Tanaka-Webster connection and we study the
interactions between the Tanaka-Webster, the bi-Legendrian and the Levi Civita
connection in a Sasakian manifold.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:36:54 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Aug 2007 11:56:18 GMT"
},
{
"version": "v3",
"created": "Sat, 23 Feb 2008 12:54:48 GMT"
}
] | 2013-06-18T00:00:00 | [
[
"Montano",
"Beniamino Cappelletti",
""
]
] |
0706.0889 | Fred Holt | Fred B. Holt | Expected gaps between prime numbers | 21 pages, LaTeX, 2 pdf figures | null | null | null | math.NT | null | We study the gaps between consecutive prime numbers directly through
Eratosthenes sieve. Using elementary methods, we identify a recursive relation
for these gaps and for specific sequences of consecutive gaps, known as
constellations. Using this recursion we can estimate the numbers of a gap or of
a constellation that occur between a prime and its square. This recursion also
has explicit implications for open questions about gaps between prime numbers,
including three questions posed by Erd\"os and Tur\'an.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:37:46 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Holt",
"Fred B.",
""
]
] |
0706.0890 | Brian Batell | Brian Batell, Tony Gherghetta | Holographic Mixing Quantified | 27 pages | Phys.Rev.D76:045017,2007 | 10.1103/PhysRevD.76.045017 | null | hep-th hep-ph | null | We compute the precise elementary/composite field content of mass eigenstates
in holographic duals of warped models in a slice of AdS_5. This is accomplished
by decomposing the bulk fields not in the usual Kaluza-Klein basis, but rather
into a holographic basis of 4D fields, corresponding to purely elementary
source or CFT composite fields. Generically, this decomposition yields kinetic
and mass mixing between the elementary and composite sectors of the holographic
theory. Depending on where the bulk zero mode is localized, the
elementary/composite content may differ radically, which we show explicitly for
several examples including the bulk Randall-Sundrum graviton, bulk gauge boson,
and Higgs boson.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 18:59:04 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Batell",
"Brian",
""
],
[
"Gherghetta",
"Tony",
""
]
] |
0706.0891 | Robert Stencel | Jeffrey L. Hopkins and Robert E. Stencel | Recent UBVJH Photometry of Epsilon Aurigae | 10 pages, PDF. Appeared in the Proceedings of the May 2007 Society
for Astronomical Sciences annual conference | null | null | null | astro-ph | null | Since first observed in the early 1980s, the Hopkins Phoenix Observatory
continues its UBV band observations of the long period (27.1 years) eclipsing
binary star system epsilon Aurigae. The UBV observations routinely produce
standard deviations or data spread better than 0.01 magnitudes many times
approaching 0.001 magnitudes. A new infrared photometer has allowed the
addition of near-infrared observations for the JH bands. Typical near-infrared
observations approach a standard deviation of data spread of 0.01 magnitudes.
The 2003 - 2005 seasons (Fall through Spring) of epsilon Aurigae observations
showed a 66.2 day variation that gradually increases in average and peak
magnitude in the UBV bands. The 2006 season (Fall 2006 to Spring 2007) data
show what appears to be a fall-back to a quiet period near maximum amplitude of
V= 3.00. This paper presents the data and compares the current season to the
past several seasons. The next eclipse is predicted to begin in 2009 and an
international campaign has been organized to coordinate new observations. These
website links are: [http://www. hposoft.com/Campaign09.html ] and [
http://www.du.edu/~rstencel/epsaur.htm ] .
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 19:07:59 GMT"
}
] | 2007-06-07T00:00:00 | [
[
"Hopkins",
"Jeffrey L.",
""
],
[
"Stencel",
"Robert E.",
""
]
] |
0706.0892 | Mauro R. Cosentino | Mauro R. Cosentino (for the STAR Collaboration) | Upsilon measurement in STAR | 6 pages, 3 figures, proceedings for Quark Matter 2006 | Int.J.Mod.Phys.E16:2110-2115,2007 | 10.1142/S0218301307007544 | null | nucl-ex | null | We present preliminary results of Upsilon production in p+p collisions at
sqrt(s)=200 GeV at central rapidity. This measurement was performed at the STAR
experiment through the Upsilon->e^+e^- decay channel. In this manuscript we
describe the experimental details, from the development of a specially designed
trigger setup to the analysis methods used to discriminate electrons from
hadrons. The production cross-section obtained B*{(dsigma/dy)|(y=0)}=91(28)(22)
pb is compatible with our expectations based on pQCD calculations.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 19:42:01 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Cosentino",
"Mauro R.",
"",
"for the STAR Collaboration"
]
] |
0706.0893 | Katarina Kova\v{c} | Katarina Kova\v{c}, Rachel S. Somerville, James E. Rhoads, Sangeeta
Malhotra, and JunXian Wang | Clustering of Lyman alpha emitters at z ~ 4.5 | 23 pages in preprint format, 4 figures, ApJ accepted | null | 10.1086/520668 | null | astro-ph | null | We present the clustering properties of 151 Lyman alpha emitting galaxies at
z ~ 4.5 selected from the Large Area Lyman Alpha (LALA) survey. Our catalog
covers an area of 36' x 36' observed with five narrowband filters. We assume
that the angular correlation function w(theta) is well represented by a power
law A_w = Theta^(-beta) with slope beta = 0.8, and we find A_w = 6.73 +/- 1.80.
We then calculate the correlation length r_0 of the real-space two-point
correlation function xi(r) = (r/r_0)^(-1.8) from A_w through the Limber
transformation, assuming a flat, Lambda-dominated universe. Neglecting
contamination, we find r_0 = 3.20 +/- 0.42 Mpc/h. Taking into account a
possible 28% contamination by randomly distributed sources, we find r_0 = 4.61
+/- 0.6 Mpc/h. We compare these results with the expectations for the
clustering of dark matter halos at this redshift in a Cold Dark Matter model,
and find that the measured clustering strength can be reproduced if these
objects reside in halos with a minimum mass of 1-2 times 10^11 Solar masses/h.
Our estimated correlation length implies a bias of b ~ 3.7, similar to that of
Lyman-break galaxies (LBG) at z ~ 3.8-4.9. However, Lyman alpha emitters are a
factor of ~ 2-16 rarer than LBGs with a similar bias value and implied host
halo mass. Therefore, one plausible scenario seems to be that Lyman alpha
emitters occupy host halos of roughly the same mass as LBGs, but shine with a
relatively low duty cycle of 6-50%.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:00:38 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kovač",
"Katarina",
""
],
[
"Somerville",
"Rachel S.",
""
],
[
"Rhoads",
"James E.",
""
],
[
"Malhotra",
"Sangeeta",
""
],
[
"Wang",
"JunXian",
""
]
] |
0706.0894 | Geraldo A. Barbosa | Geraldo A. Barbosa | Transverse coincidence-structures in spontaneous parametric
down-conversion with orbital angular momentum: Theory | 14 pages, 5 figures | null | 10.1103/PhysRevA.76.033821 | null | quant-ph | null | Coincidence-structures in the transverse plane of Type-II spontaneous
parametric down-conversion carrying orbital angular momentum are obtained.
Azimuthal symmetry breaking around the pump beam direction reveals itself on
these quantum images. Analytical expressions for the amplitude probability of
the down conversion process are shown including the nonlinear polarizability
components.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:02:46 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Barbosa",
"Geraldo A.",
""
]
] |
0706.0895 | Zheng Zheng | Leonid Chuzhoy (1) Zheng Zheng (2) ((1) University of Texas at Austin,
(2) Institute for Advanced Study) | Radiative Transfer Effect on Ultraviolet Pumping of the 21cm Line in the
High Redshift Universe | 7 pages, 4 figures, submitted to ApJ | null | 10.1086/522491 | null | astro-ph | null | During the epoch of reionization the 21cm signal is sensitive to the
scattering rate of the ultraviolet photons, redshifting across the Lyman_alpha
resonance. Here we calculate the photon scattering rate profile for a single
ultraviolet source. After taking into account previously neglected natural
broadening of the resonance line, we find that photons approach the resonance
frequency and experience most scatterings at a significantly smaller distance
from the source than naively expected r=(dnu/nu_0)(c/H), where dnu=nu-nu_0 is
the initial frequency offset, and the discrepancy increases as the initial
frequency offset decreases. As a consequence, the scattering rate P(r) drops
much faster with increasing distance than the previously assumed 1/r^2 profile.
Near the source (r<1Mpc comoving), the scattering rate of photons that redshift
into the Ly_alpha resonance converges to P(r) \propto r^{-7/3}. The scattering
rate of Ly_alpha photons produced by splitting of photons that redshift into a
higher resonance (Ly_gamma, Ly_delta, etc.) is only weakly affected by the
radiative transfer, while the sum of scattering rates of Ly_alpha photons
produced from all higher resonances also converges to P(r) \propto r^{-7/3}
near the source. At 15<z<35, on scales of ~0.01-20Mpc/h (comoving), the total
scattering rate of Ly_alpha photons from all Lyman resonances is found to be
higher by a factor of ~1+0.3[(1+z)/20]^{2/3} than obtained without full
radiative transfer. Consequently, during the early stage of reionization, the
differential brightness of 21cm signal against the cosmic microwave background
is also boosted by a similar factor.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:08:31 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Chuzhoy",
"Leonid",
""
],
[
"Zheng",
"Zheng",
""
]
] |
0706.0896 | Marco Miranda | M. Miranda (University of Zurich) and A.V. Macci\`o (MPIA-Heidelberg) | Constraining Warm Dark Matter using QSO gravitational lensing | One equation added, typo in eq: 5 corrected, minor changes to match
the accepted version by MNRAS | null | 10.1111/j.1365-2966.2007.12440.x | null | astro-ph | null | Warm Dark Matter (WDM) has been invoked to resolve apparent conflicts of Cold
Dark Matter (CDM) models with observations on subgalactic scales. In this work
we provide a new and independent lower limit for the WDM particle mass (e.g.
sterile neutrino) through the analysis of image fluxes in gravitationally
lensed QSOs.
Starting from a theoretical unperturbed cusp configuration we analyze the
effects of intergalactic haloes in modifying the fluxes of QSO multiple images,
giving rise to the so-called anomalous flux ratio. We found that the global
effect of such haloes strongly depends on their mass/abundance ratio and it is
maximized for haloes in the mass range $10^6-10^8 \Msun$.
This result opens up a new possibility to constrain CDM predictions on small
scales and test different warm candidates, since free streaming of warm dark
matter particles can considerably dampen the matter power spectrum in this mass
range. As a consequence, while a ($\Lambda$)CDM model is able to produce flux
anomalies at a level similar to those observed, a WDM model, with an
insufficiently massive particle, fails to reproduce the observational
evidences.
Our analysis suggests a lower limit of a few keV ($m_{\nu} \sim 10$) for the
mass of warm dark matter candidates in the form of a sterile neutrino. This
result makes sterile neutrino Warm Dark Matter less attractive as an
alternative to Cold Dark Matter, in good agreement with previous findings from
Lyman-$\alpha$ forest and Cosmic Microwave Background analysis.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:11:46 GMT"
},
{
"version": "v2",
"created": "Tue, 11 Sep 2007 09:59:40 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Miranda",
"M.",
"",
"University of Zurich"
],
[
"Macciò",
"A. V.",
"",
"MPIA-Heidelberg"
]
] |
0706.0897 | Maria Amparo T\'ortola | S. S. Masood, S. Nasri, J. Schechter, M. A. T\'ortola, J. W. F. Valle
and C. Weinheimer | Exact relativistic beta decay endpoint spectrum | 12 pages, 3 figures | Phys.Rev.C76:045501,2007 | 10.1103/PhysRevC.76.045501 | null | hep-ph nucl-ex | null | The exact relativistic form for the beta decay endpoint spectrum is derived
and presented in a simple factorized form. We show that our exact formula can
be well approximated to yield the endpoint form used in the fit method of the
KATRIN collaboration. We also discuss the three neutrino case and how
information from neutrino oscillation experiments may be useful in analyzing
future beta decay endpoint experiments.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:04:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Masood",
"S. S.",
""
],
[
"Nasri",
"S.",
""
],
[
"Schechter",
"J.",
""
],
[
"Tórtola",
"M. A.",
""
],
[
"Valle",
"J. W. F.",
""
],
[
"Weinheimer",
"C.",
""
]
] |
0706.0898 | M\'enard Brice | Brice M\'enard (1), Daniel Nestor (2), David Turnshek (3), Anna Quider
(3), Gordon Richards (4), Doron Chelouche (5), Sandhya Rao (3); ((1) CITA,
(2) IoA Cambridge, (3) Univ. of Pittsburgh, (4) Drexel Univ., (5) IAS) | Lensing, reddening and extinction effects of MgII absorbers from z=0.4
to z=2 | Submitted | null | 10.1111/j.1365-2966.2008.12909.x | null | astro-ph | null | Using a sample of almost 7000 strong MgII absorbers with 0.4 < z < 2.2
detected in the SDSS DR4 dataset, we investigate the gravitational lensing and
dust extinction effects they induce on background quasars. After carefully
quantifying several selection biases, we isolate the reddening effects as a
function of redshift and absorber rest equivalent width, W_0. We find the
amount of dust to increase with cosmic time as (1+z)^(-1.1 +/- 0.4), following
the evolution of cosmic star density or integrated star formation rate. We
measure the reddening effects over a factor 30 in E(B-V) and we find the dust
column density to be proportional to W_0^(1.9 +/- 0.2), which provides an
important scaling for theoretical modeling of metal absorbers. We also measure
the dust-to-metals ratio and find it similar to that of the Milky Way.
In contrast to previous studies, we do not detect any gravitational
magnification by MgII systems. We measure the upper limit \mu<1.10 and discuss
the origin of the discrepancy. Finally, we estimate the fraction of absorbers
missed due to extinction effects and show that it rises from 1 to 50% in the
range 1<W_0<6 Angstrom. We parametrize this effect and provide a correction for
recovering the intrinsic distribution of absorber rest equivalent widths.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 19:49:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ménard",
"Brice",
""
],
[
"Nestor",
"Daniel",
""
],
[
"Turnshek",
"David",
""
],
[
"Quider",
"Anna",
""
],
[
"Richards",
"Gordon",
""
],
[
"Chelouche",
"Doron",
""
],
[
"Rao",
"Sandhya",
""
],
[
";",
"",
""
]
] |
0706.0899 | Emmanuel Momjian | E. Momjian, C. L. Carilli, D. A. Riechers, F. Walter | High Sensitivity Array Observations of the $z = 4.4$ QSO BRI 1335-0417 | 13 pages, 3 figures, AJ accepted | Astron.J.134:694-697,2007 | 10.1086/519840 | null | astro-ph | null | We present sensitive phase-referenced VLBI results on the radio continuum
emission from the $z=4.4$ QSO BRI 1335--0417. The observations were carried out
at 1.4 GHz using the High Sensitivity Array (HSA). Our sensitive VLBI image at
$189 \times 113$ mas ($1.25 \times 0.75$ kpc) resolution shows continuum
emission in BRI 1335--0417 with a total flux density of $208 \pm 46 \mu$Jy,
consistent with the flux density measured with the VLA. The size of the source
at FWHM is $255 \times 138$ mas ($1.7 \times 0.9$ kpc) and the derived
intrinsic brightness temperature is $\sim 3.5\times 10^4$ K. No continuum
emission is detected at the full VLBI resolution ($32 \times 7$ mas, $211
\times 46$ pc), with a 4$\sigma$ point source upper limit of 34 $\mu$Jy
beam$^{-1}$, or an upper limit to the intrinsic brightness temperature of
$5.6\times 10^5$ K. The highest angular resolution with at least a 4.5$\sigma$
detection of the radio continuum emission is $53 \times 27$ mas ($0.35 \times
0.18$ kpc). At this resolution, the image shows a continuum feature in BRI
1335--0417 with a size of $64 \times 35$ mas ($0.42 \times 0.23$ kpc) at FWHM,
and intrinsic brightness temperature of $\sim 2\times 10^5$ K. The extent of
the observed continuum sources at 1.4 GHz and the derived brightness
temperatures show that the radio emission (and thus presumably the far-infrared
emission) in BRI 1335--0417 is powered by a major starburst, with a massive
star formation rate of order a few thousand M_{\odot} {\rm yr}^{-1}$. Moreover,
the absence of any compact high-brightness temperature source suggests that
there is no radio-loud AGN in this $z=4.4$ QSO.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:08:31 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Momjian",
"E.",
""
],
[
"Carilli",
"C. L.",
""
],
[
"Riechers",
"D. A.",
""
],
[
"Walter",
"F.",
""
]
] |
0706.0900 | Jeremy S. Heyl | Jeremy S. Heyl | Constraining white-dwarf kicks in globular clusters | 4 pages, 3 figures, changes to reflect version accepted for MNRAS
Letters | null | 10.1111/j.1745-3933.2007.00369.x | null | astro-ph | null | The wind of an asymptotic-giant-branch stars is sufficiently strong that if
it is slightly asymmetric, it can propel the star outside of the open cluster
of its birth or significantly alter its trajectory through a globular cluster;
therefore, if these stellar winds are asymmetric, one would expect a deficit of
white dwarfs of all ages in open clusters and for young white dwarfs to be less
radially concentrated than either their progenitors or older white dwarfs in
globular clusters. This latter effect has recently been observed. Hence,
detailed studies of the radial distribution of young white dwarfs in globular
clusters could provide a unique probe of mass loss on the asymptotic giant
branch and during the formation of planetary nebulae both as a function of
metallicity and a limited range of stellar mass.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:09:51 GMT"
},
{
"version": "v2",
"created": "Fri, 7 Sep 2007 17:42:51 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Heyl",
"Jeremy S.",
""
]
] |
0706.0901 | Albert Kong | A.K.H. Kong (MIT), Y.J. Yang, P.-Y. Hsieh (ASIAA, Taiwan), D.S.Y. Mak,
C.S.J. Pun (University of Hong Kong) | The Ultraluminous X-ray Sources near the Center of M82 | 9 pages, 8 figures. Accepted for publication in ApJ | null | 10.1086/522291 | null | astro-ph | null | We report the identification of a recurrent ultraluminous X-ray source (ULX),
a highly absorbed X-ray source (possibly a background AGN), and a young
supernova remnant near the center of the starburst galaxy M82. From a series of
Chandra observations taken from 1999 to 2005, we found that the transient ULX
first appeared in 1999 October. The source turned off in 2000 January, but
later reappeared and has been active since then. The X-ray luminosity of this
source varies from below the detection level (~2.5e38 erg/s) to its active
state in between ~7e39 erg/s and 1.3e40 erg/s (in the 0.5-10 keV energy band)
and shows unusual spectral changes. The X-ray spectra of some Chandra
observations are best fitted with an absorbed power-law model with photon index
ranging from 1.3 to 1.7. These spectra are similar to those of Galactic black
hole binary candidates seen in the low/hard state except that a very hard
spectrum was seen in one of the observations. By comparing with near infrared
images taken with the Hubble Space Telescope, the ULX is found to be located
within a young star cluster. Radio imaging indicates that it is associated with
a H II region. We suggest that the ULX is likely to be a > 100 solar mass
intermediate-mass black hole in the low/hard state. In addition to the
transient ULX, we also found a highly absorbed hard X-ray source which is
likely to be an AGN and an ultraluminous X-ray emitting young supernova remnant
which may be related to a 100-year old gamma-ray burst event, within 2 arcsec
of the transient ULX.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:14:16 GMT"
},
{
"version": "v2",
"created": "Tue, 7 Aug 2007 21:52:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kong",
"A. K. H.",
"",
"MIT"
],
[
"Yang",
"Y. J.",
"",
"ASIAA, Taiwan"
],
[
"Hsieh",
"P. -Y.",
"",
"ASIAA, Taiwan"
],
[
"Mak",
"D. S. Y.",
"",
"University of Hong Kong"
],
[
"Pun",
"C. S. J.",
"",
"University of Hong Kong"
]
] |
0706.0902 | Lester Hedges | Lester O. Hedges, Juan P. Garrahan | Dynamic facilitation explains democratic particle motion of metabasin
transitions | 6 pages, 6 figures | J. Phys. A: Math. Theor. 41 (2008) 324006. | 10.1088/1751-8113/41/32/324006 | null | cond-mat.stat-mech cond-mat.soft | null | Transitions between metabasins in supercooled liquids seem to occur through
rapid "democratic" collective particle rearrangements. Here we show that this
apparent homogeneous particle motion is a direct consequence of dynamic
facilitation. We do so by studying metabasin transitions in facilitated spin
models and constrained lattice gases. We find that metabasin transitions occur
through a sequence of locally facilitated events taking place over a relatively
short time frame. When observed on small enough spatial windows these events
appear sudden and homogeneous. Our results indicate that metabasin transitions
are essentially "non-democratic" in origin and yet another manifestation of
dynamical heterogeneity in glass formers.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 13:39:33 GMT"
},
{
"version": "v2",
"created": "Thu, 7 Jun 2007 20:59:25 GMT"
}
] | 2008-07-31T00:00:00 | [
[
"Hedges",
"Lester O.",
""
],
[
"Garrahan",
"Juan P.",
""
]
] |
0706.0903 | Georgy Karev | Faina Berezovskaya, Artem Novozhilov, Georgy Karev | Families of traveling impulses and fronts in some models with
cross-diffusion | 20 pages, 9 figures; submitted to Journal of Nonlinear Analysis: Real
World Applications | null | null | null | cs.NA | null | An analysis of traveling wave solutions of partial differential equation
(PDE) systems with cross-diffusion is presented. The systems under study fall
in a general class of the classical Keller-Segel models to describe chemotaxis.
The analysis is conducted using the theory of the phase plane analysis of the
corresponding wave systems without a priory restrictions on the boundary
conditions of the initial PDE. Special attention is paid to families of
traveling wave solutions. Conditions for existence of front-impulse,
impulse-front, and front-front traveling wave solutions are formulated. In
particular, the simplest mathematical model is presented that has an
impulse-impulse solution; we also show that a non-isolated singular point in
the ordinary differential equation (ODE) wave system implies existence of
free-boundary fronts. The results can be used for construction and analysis of
different mathematical models describing systems with chemotaxis.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:19:20 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Berezovskaya",
"Faina",
""
],
[
"Novozhilov",
"Artem",
""
],
[
"Karev",
"Georgy",
""
]
] |
0706.0904 | Sascha Husa | Sascha Husa, Mark Hannam, Jose A. Gonzalez, Ulrich Sperhake, Bernd
Bruegmann | Reducing eccentricity in black-hole binary evolutions with initial
parameters from post-Newtonian inspiral | 6 pages, 3 figures, 1 table | Phys.Rev.D77:044037,2008 | 10.1103/PhysRevD.77.044037 | null | gr-qc | null | Standard choices of quasi-circular orbit parameters for black-hole binary
evolutions result in eccentric inspiral. We introduce a conceptually simple
method, which is to integrate the post-Newtonian equations of motion through
hundreds of orbits, and read off the values of the momenta at the separation at
which we wish to start a fully general relativistic numerical evolution. For
the particular case of non-spinning equal-mass inspiral with an initial
coordinate separation of $D = 11M$ we show that this approach reduces the
eccentricity by at least a factor of five to $e < 0.002$ as compared to using
standard quasi-circular initial parameters.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 18:28:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Husa",
"Sascha",
""
],
[
"Hannam",
"Mark",
""
],
[
"Gonzalez",
"Jose A.",
""
],
[
"Sperhake",
"Ulrich",
""
],
[
"Bruegmann",
"Bernd",
""
]
] |
0706.0905 | Marek Korkusinski | Irene Puerto-Gimenez, Marek Korkusinski, Pawel Hawrylak | LCHO-CI method for the voltage control of exchange interaction in gated
lateral quantum dot networks | 23 pages, 7 figures, submitted to Phys. Rev. B | null | null | null | cond-mat.mes-hall cond-mat.mtrl-sci | null | We present a computational LCHO-CI approach allowing for the simulation of
exchange interactions in gated lateral quantum dot networks. The approach is
based on single-particle states calculated using a linear combination of
harmonic orbitals (LCHO) of each of the dots, and a configuration interaction
(CI) approach to the interacting electron problem. The LCHO-CI method is
applied to a network of three quantum dots with one electron spin per dot, and
a Heisenberg spin Hamiltonian is derived. The manipulation of spin states of a
three-spin molecule by applying bias to one of the dots is demonstrated and
related to the bias dependence of effective exchange interaction parameters.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:41:01 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Puerto-Gimenez",
"Irene",
""
],
[
"Korkusinski",
"Marek",
""
],
[
"Hawrylak",
"Pawel",
""
]
] |
0706.0906 | Anthony Clark Mr. | A. C. Clark, J. T. West, and M. H. W. Chan | Nonclassical Rotational Inertia in Single Crystal Helium | 4 figures | null | 10.1103/PhysRevLett.99.135302 | null | cond-mat.other cond-mat.stat-mech | null | It has been proposed that the observed nonclassical rotational inertia (NCRI)
in solid helium results from the superflow of thin liquid films along
interconnected grain boundaries within the sample. We have carried out new
torsional oscillator measurements on large helium crystals grown under constant
temperature and pressure. We observe NCRI in all samples, indicating that the
phenomenon cannot be explained by a superfluid film flowing along grain
boundaries.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:30:51 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jul 2007 01:43:57 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Clark",
"A. C.",
""
],
[
"West",
"J. T.",
""
],
[
"Chan",
"M. H. W.",
""
]
] |
0706.0907 | Christopher Tompkins III | C. Robinson Tompkins | Latin Square Thue-Morse Sequences are Overlap-Free | 5 pages, 1 figure | null | null | null | math.NT | null | We define a morphism based upon a Latin square that generalizes the
Thue-Morse morphism. We prove that fixed points of this morphism are
overlap-free sequences generalizing results of Allouche - Shallit and Frid.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:35:58 GMT"
},
{
"version": "v2",
"created": "Tue, 18 Sep 2007 14:37:41 GMT"
},
{
"version": "v3",
"created": "Wed, 31 Oct 2007 16:14:09 GMT"
}
] | 2007-10-31T00:00:00 | [
[
"Tompkins",
"C. Robinson",
""
]
] |
0706.0908 | Artur Lopes O. | Artur O. Lopes and Elismar R. Oliveira | Entropy and Variational principles for holonomic probabilities of IFS | null | null | null | null | math.DS | null | Associated to a IFS one can consider a continuous map $\hat{\sigma} :
[0,1]\times \Sigma \to [0,1]\times \Sigma$, defined by
$\hat{\sigma}(x,w)=(\tau_{X_{1}(w)}(x), \sigma(w))$ were $\Sigma=\{0,1, ...,
d-1\}^{\mathbb{N}}$, $\sigma: \Sigma \to \Sigma$ is given
by$\sigma(w_{1},w_{2},w_{3},...)=(w_{2},w_{3},w_{4}...)$ and $X_{k} : \Sigma
\to \{0,1, ..., n-1\}$ is the projection on the coordinate $k$. A
$\rho$-weighted system, $\rho \geq 0$, is a weighted system $([0,1], \tau_{i},
u_{i})$ such that there exists a positive bounded function $h : [0,1] \to
\mathbb{R}$ and probability $\nu $ on $[0,1]$ satisfying $ P_{u}(h)=\rho h,
\quad P_{u}^{*}(\nu)=\rho\nu$. A probability $\hat{\nu}$ on $[0,1]\times
\Sigma$ is called holonomic for $\hat{\sigma}$ if $ \int g \circ \hat{\sigma}
d\hat{\nu}= \int g d\hat{\nu}, \forall g \in C([0,1])$. We denote the set of
holonomic probabilities by ${\cal H}$. Via disintegration, holonomic
probabilities $\hat{\nu}$ on $[0,1]\times \Sigma$ are naturally associated to a
$\rho$-weighted system. More precisely, there exist a probability $\nu$ on
$[0,1]$ and $u_i, i\in\{0, 1,2,..,d-1\}$ on $[0,1]$, such that is
$P_{u}^*(\nu)=\nu$. We consider holonomic ergodic probabilities. For a
holonomic probability we define entropy. Finally, we analyze the problem: given
$\phi \in \mathbb{B}^{+}$, find the solution of the maximization pressure
problem $$p(\phi)=$$
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:49:09 GMT"
},
{
"version": "v2",
"created": "Thu, 18 Oct 2007 12:39:58 GMT"
}
] | 2007-10-18T00:00:00 | [
[
"Lopes",
"Artur O.",
""
],
[
"Oliveira",
"Elismar R.",
""
]
] |
0706.0909 | Moira Gresham | Moira I. Gresham and Mark B. Wise | Color Octet Scalar Production at the LHC | 15 pages, 5 figures | Phys.Rev.D76:075003,2007 | 10.1103/PhysRevD.76.075003 | CALT 68-2652 | hep-ph | null | New physics at the weak scale that can couple to quarks typically gives rise
to unacceptably large flavor changing neutral currents. An attractive way to
avoid this problem is to impose the principal of minimal flavor violation
(MFV). Recently it was noted that in MFV only scalars with the same gauge
quantum numbers as the standard model Higgs doublet or color octet scalars with
the same weak quantum numbers as the Higgs doublet can couple to quarks. In
this paper we compute the one-loop rate for production of a single color octet
scalar through gluon fusion at the LHC, which can become greater than the tree
level pair production rate for octet scalar masses around a TeV. We also
calculate the precision electroweak constraint from Z decays to a b and anti-b
quark; this constraint on color octet mass and Yukawa coupling affects the
allowed range for single octet scalar production through gluon fusion.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 18:51:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gresham",
"Moira I.",
""
],
[
"Wise",
"Mark B.",
""
]
] |
0706.0910 | Evans M. Harrell II | A. El Soufi, E.M. Harrell, and S. Ilias | Universal inequalities for the eigenvalues of Laplace and Schr\"odinger
operators on submanifolds, | null | null | null | null | math.SP math.DG | null | We establish inequalities for the eigenvalues of Schr\"{o}dinger operators on
compact submanifolds (possibly with nonempty boundary) of Euclidean spaces, of
spheres, and of real, complex and quaternionic projective spaces, which are
related to inequalities for the Laplacian on Euclidean domains due to Payne,
P\'olya, and Weinberger and to Yang, but which depend in an explicit way on the
mean curvature. In later sections, we prove similar results for Schr\"{o}dinger
operators on homogeneous Riemannian spaces and, more generally, on any
Riemannian manifold that admits an eigenmap into a sphere, as well as for the
Kohn Laplacian on subdomains of the Heisenberg group.
Among the consequences of this analysis are an extension of Reilly's
inequality, bounding any eigenvalue of the Laplacian in terms of the mean
curvature, and spectral criteria for the immersibility of manifolds in
homogeneous spaces.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:51:03 GMT"
}
] | 2007-06-08T00:00:00 | [
[
"Soufi",
"A. El",
""
],
[
"Harrell",
"E. M.",
""
],
[
"Ilias",
"S.",
""
]
] |
0706.0911 | Marek Korkusinski | M. Korkusinski, P. Hawrylak, A. Babinski, M. Potemski, S. Raymond, Z.
Wasilewski | Optical readout of charge and spin in a self-assembled quantum dot in a
strong magnetic field | 9 pages, 3 figures, submitted to Europhysics Letters | null | 10.1209/0295-5075/79/47005 | null | cond-mat.mes-hall cond-mat.mtrl-sci | null | We present a theory and experiment demonstrating optical readout of charge
and spin in a single InAs/GaAs self-assembled quantum dot. By applying a
magnetic field we create the filling factor 2 quantum Hall singlet phase of the
charged exciton. Increasing or decreasing the magnetic field leads to
electronic spin-flip transitions and increasing spin polarization. The
increasing total spin of electrons appears as a manifold of closely spaced
emission lines, while spin flips appear as discontinuities of emission lines.
The number of multiplets and discontinuities measures the number of carriers
and their spin. We present a complete analysis of the emission spectrum of a
single quantum dot with N=4 electrons and a single hole, calculated and
measured in magnetic fields up to 23 Tesla.
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 21:25:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Korkusinski",
"M.",
""
],
[
"Hawrylak",
"P.",
""
],
[
"Babinski",
"A.",
""
],
[
"Potemski",
"M.",
""
],
[
"Raymond",
"S.",
""
],
[
"Wasilewski",
"Z.",
""
]
] |
0706.0912 | Jeremy S. Heyl | Jeremy S. Heyl | Orbital evolution with white-dwarf kicks | 6 pages, 2 figures, added many intermediate equations, version
accepted by MNRAS | null | 10.1111/j.1365-2966.2007.12441.x | null | astro-ph | null | Recent observations of white dwarfs in globular clusters indicate that these
stars may get a velocity kick during their time as giants. This velocity kick
could originate naturally if the mass loss while on the asymptotic giant branch
is slightly asymmetric. If white dwarfs get a kick comparable to the orbital
velocity of the binary, the initial Runge-Lenz vector (eccentricity vector) of
the orbit is damped to be replaced by a component pointing toward the cross
product of the initial angular momentum and the force. The final eccentricity
may be of order unity and if the kick is sufficiently large, the system may be
disrupted. These results may have important ramifications for the evolution of
binary stars and planetary systems
| [
{
"version": "v1",
"created": "Wed, 6 Jun 2007 20:52:57 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Sep 2007 14:07:51 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Heyl",
"Jeremy S.",
""
]
] |
0706.0913 | K. Paech | K. Paech, W. Bauer, S. Pratt | Zipf's law in Nuclear Multifragmentation and Percolation Theory | 8 pages, 11 figures, submitted to PRC | Phys.Rev.C76:054603,2007 | 10.1103/PhysRevC.76.054603 | null | nucl-th | null | We investigate the average sizes of the $n$ largest fragments in nuclear
multifragmentation events near the critical point of the nuclear matter phase
diagram. We perform analytic calculations employing Poisson statistics as well
as Monte Carlo simulations of the percolation type. We find that previous
claims of manifestations of Zipf's Law in the rank-ordered fragment size
distributions are not born out in our result, neither in finite nor infinite
systems. Instead, we find that Zipf-Mandelbrot distributions are needed to
describe the results, and we show how one can derive them in the infinite size
limit. However, we agree with previous authors that the investigation of
rank-ordered fragment size distributions is an alternative way to look for the
critical point in the nuclear matter diagram.
| [
{
"version": "v1",
"created": "Thu, 7 Jun 2007 12:53:43 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Paech",
"K.",
""
],
[
"Bauer",
"W.",
""
],
[
"Pratt",
"S.",
""
]
] |
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