4,037 research outputs found
Measurement of the Homogeneous Contact of a Unitary Fermi gas
By selectively probing the center of a trapped gas, we measure the local, or
homogeneous, contact of a unitary Fermi gas as a function of temperature. Tan's
contact, C, is proportional to the derivative of the energy with respect to the
interaction strength, and is thus an essential thermodynamic quantity for a gas
with short-range correlations. Theoretical predictions for the temperature
dependence of C differ substantially, especially near the superfluid
transition, Tc, where C is predicted to either sharply decrease, sharply
increase, or change very little. For T/T_F>0.4, our measurements of the
homogeneous gas contact show a gradual decrease of C with increasing
temperature, as predicted by theory. We observe a sharp decrease in C at
T/T_F=0.16, which may be due to the superfluid phase transition. While a sharp
decrease in C below Tc is predicted by some many-body theories, we find that
none of the predictions fully accounts for the data.Comment: 5 pages, including a supplementary material section (10 pages).
Rewriting of the introduction and discussion section
Holographic s-wave condensate with non-linear electrodynamics: A nontrivial boundary value problem
In this paper, considering the probe limit, we analytically study the onset
of holographic s-wave condensate in the planar Schwarzschild-AdS background.
Inspired by various low energy features of string theory, in the present work
we replace the conventional Maxwell action by a (non-linear) Born-Infeld (BI)
action which essentially corresponds to the higher derivative corrections of
the gauge fields. Based on a variational method, which is commonly known as the
Sturm-Liouville (SL) eigenvalue problem and considering a non-trivial
asymptotic solution for the scalar field, we compute the critical temperature
for the s-wave condensation. The results thus obtained analytically agree well
with the numerical findings\cite{hs19}. As a next step, we extend our
perturbative technique to compute the order parameter for the condensation.
Interestingly our analytic results are found to be of the same order as the
numerical values obtained earlier.Comment: Minor revision, accepted for publication in Phys. Rev.
A Canonical Approach to the Quantization of the Damped Harmonic Oscillator
We provide a new canonical approach for studying the quantum mechanical
damped harmonic oscillator based on the doubling of degrees of freedom
approach. Explicit expressions for Lagrangians of the elementary modes of the
problem, characterising both forward and backward time propagations are given.
A Hamiltonian analysis, showing the equivalence with the Lagrangian approach,
is also done. Based on this Hamiltonian analysis, the quantization of the model
is discussed.Comment: Revtex, 6 pages, considerably expanded with modified title and refs.;
To appear in J.Phys.
Critical behavior of Born Infeld AdS black holes in higher dimensions
Based on a canonical framework, we investigate the critical behavior of
Born-Infeld AdS black holes in higher dimensions. As a special case,
considering the appropriate limit, we also analyze the critical phenomena for
Reissner Nordstrom AdS black holes. The critical points are marked by the
divergences in the heat capacity at constant charge. The static critical
exponents associated with various thermodynamic entities are computed and shown
to satisfy the thermodynamic scaling laws. These scaling laws have also been
found to be compatible with the static scaling hypothesis. Furthermore, we show
that the values of these exponents are universal and do not depend on the
spatial dimensionality of the AdS space. We also provide a suggestive way to
calculate the critical exponents associated with the spatial correlation which
satisfy the scaling laws of second kind.Comment: LaTex, 22 pages, 12 figures, minor modifications in text, To appear
in Phys. Rev.
Angioarchitectural evolution of clival dural arteriovenous fistulas in two patients.
Dural arteriovenous fistulas (dAVFs) may present in a variety of ways, including as carotid-cavernous sinus fistulas. The ophthalmologic sequelae of carotid-cavernous sinus fistulas are known and recognizable, but less commonly seen is the rare clival fistula. Clival dAVFs may have a variety of potential anatomical configurations but are defined by the involvement of the venous plexus just overlying the bony clivus. Here we present two cases of clival dAVFs that most likely evolved from carotid-cavernous sinus fistulas
Gauge Symmetries on -Deformed Spaces
A Hamiltonian formulation of gauge symmetries on noncommutative (
deformed) spaces is discussed. Both cases- star deformed gauge transformation
with normal coproduct and undeformed gauge transformation with twisted
coproduct- are considered. While the structure of the gauge generator is
identical in either case, there is a difference in the computation of the
graded Poisson brackets that yield the gauge transformations. Our analysis
provides a novel interpretation of the twisted coproduct for gauge
transformations.Comment: LaTex, 20 pages, no figure
Supersymmetric Pair Correlation Function of Wilson Loops
We give a path integral derivation of the annulus diagram in a supersymmetric
theory of open and closed strings with Dbranes. We compute the pair correlation
function of Wilson loops in the generic weakly coupled supersymmetric flat
spacetime background with Dbranes. We obtain a -u^4/r^9 potential between heavy
nonrelativistic sources in a supersymmetric gauge theory at short distances.Comment: 18 pages, Revte
Discrete versions of some Dirac type equations and plane wave solutions
A discrete version of the plane wave solution to some discrete Dirac type
equations in the spacetime algebra is established. The conditions under which a
discrete analogue of the plane wave solution satisfies the discrete Hestenes
equation are briefly discussed.Comment: 12 pages. arXiv admin note: text overlap with arXiv:1609.0459
Seiberg-Witten-type Maps for Currents and Energy-Momentum Tensors in Noncommutative Gauge Theories
We derive maps relating the currents and energy-momentum tensors in
noncommutative (NC) gauge theories with their commutative equivalents. Some
uses of these maps are discussed. Especially, in NC electrodynamics, we obtain
a generalization of the Lorentz force law. Also, the same map for anomalous
currents relates the Adler-Bell-Jackiw type NC covariant anomaly with the
standard commutative-theory anomaly. For the particular case of two dimensions,
we discuss the implications of these maps for the Sugawara-type energy-momentum
tensor.Comment: 14 pages, JHEP styl
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