10,233 research outputs found
Diffeomorphism on Horizon as an Asymptotic Isometry of Schwarzschild Black Hole
It is argued that the diffeomorphism on the horizontal sphere can be regarded
as a nontrivial asymptotic isometry of the Schwarzschild black hole. We propose
a new boundary condition of asymptotic metrics near the horizon and show that
the condition admits the local time-shift and diffeomorphism on the horizon as
the asymptotic symmetry.Comment: 18 pages, no figures, corrected some typo
Tilt-Induced Anisotropic to Isotropic Phase Transition at
A modest in-plane magnetic field \Bpar\ is sufficient to destroy the
fractional quantized Hall states at and 7/2 and replace them with
anisotropic compressible phases. Remarkably, we find that at larger \Bpar\
these anisotropic phases can themselves be replaced by isotropic compressible
phases reminiscent of the composite fermion fluid at . We present
strong evidence that this transition is a consequence of the mixing of Landau
levels from different electric subbands. We also report surprising dependences
of the energy gaps at and 7/3 on the width of the confinement
potential.Comment: Accepted by Phys. Rev. Lett. This is a final version with rewritten
introduction and modified figure
Scaling properties of the redshift power spectrum: theoretical models
We report the results of an analysis of the redshift power spectrum
in three typical Cold Dark Matter (CDM) cosmological models, where
is the cosine of the angle between the wave vector and the line-of-sight.
Two distinct biased tracers derived from the primordial density peaks of
Bardeen et al. and the cluster-underweight model of Jing, Mo, & B\"orner are
considered in addition to the pure dark matter models. Based on a large set of
high resolution simulations, we have measured the redshift power spectrum for
the three tracers from the linear to the nonlinear regime. We investigate the
validity of the relation - guessed from linear theory - in the nonlinear regime
where
is the real space power spectrum, and equals . The
damping function which should generally depend on , , and
, is found to be a function of only one variable
. This scaling behavior extends into the nonlinear regime,
while can be accurately expressed as a Lorentz function - well known from
linear theory - for values . The difference between
and the pairwise velocity dispersion defined by the 3-D peculiar velocity of
the simulations (taking ) is about 15%. Therefore is a
good indicator of the pairwise velocity dispersion. The exact functional form
of depends on the cosmological model and on the bias scheme. We have given
an accurate fitting formula for the functional form of for the models
studied.Comment: accepted for publication in ApJ;24 pages with 7 figures include
Associated Production of a Top Quark and a Charged Higgs Boson
We compute the inclusive and differential cross sections for the associated
production of a top quark along with a charged Higgs boson at hadron colliders
to next-to-leading order (NLO) in perturbative quantum chromodynamics (QCD) and
in supersymmetric QCD. For small Higgs boson masses we include top quark pair
production diagrams with subsequent top quark decay into a bottom quark and a
charged Higgs boson. We compare the NLO differential cross sections obtained in
the bottom parton picture with those for the gluon-initiated production process
and find good agreement. The effects of supersymmetric loop contributions are
explored. Only the corrections to the Yukawa coupling are sizable in the
potential discovery region at the CERN Large Hadron Collider (LHC). All
expressions and numerical results are fully differential, permitting selections
on the momenta of both the top quark and the charged Higgs boson.Comment: 15 pages, 9 figures; section, figures, equations and references
added, version to appear in PRD, 33 pages, 11 figure
Jack vertex operators and realization of Jack functions
We give an iterative method to realize general Jack functions from Jack
functions of rectangular shapes. We first show some cases of Stanley's
conjecture on positivity of the Littlewood-Richardson coefficients, and then
use this method to give a new realization of Jack functions. We also show in
general that vectors of products of Jack vertex operators form a basis of
symmetric functions. In particular this gives a new proof of linear
independence for the rectangular and marked rectangular Jack vertex operators.
Thirdly a generalized Frobenius formula for Jack functions was given and was
used to give new evaluation of Dyson integrals and even powers of Vandermonde
determinant.Comment: Expanded versio
Description of Hf in the constrained relativistic mean field theory
The properties of the ground state of Hf and the isomeric state
Hf are studied within the adiabatic and diabatic constrained
relativistic mean field (RMF) approaches. The RMF calculations reproduce well
the binding energy and the deformation for the ground state of Hf.
Using the ground state single-particle eigenvalues obtained in the present
calculation, the lowest excitation configuration with is found to
be
. Its excitation energy calculated by the
RMF theory with time-odd fields taken into account is equal to 2.801 MeV, i.e.,
close to the Hf experimental excitation energy 2.446 MeV. The
self-consistent procedure accounting for the time-odd component of the meson
fields is the most important aspect of the present calculation.Comment: 12 pages(preprint), 2 figures, 1 tabl
The finite size effect of galaxies on the cosmic virial theorem and the pairwise peculiar velocity dispersions
We discuss the effect of the finite size of galaxies on estimating
small-scale relative pairwise peculiar velocity dispersions from the cosmic
virial theorem (CVT). Specifically we evaluate the effect by incorporating the
finite core radius in the two-point correlation function of mass, i.e.
and the effective gravitational force
softening on small scales. We analytically obtain the lowest-order
correction term for which is in quantitative agreement with the
full numerical evaluation. With a nonzero and/or the cosmic virial
theorem is no longer limited to the case of . We present accurate
fitting formulae for the CVT predicted pairwise velocity dispersion for the
case of . Compared with the idealistic point-mass approximation
(), the finite size effect can significantly reduce the small-scale
velocity dispersions of galaxies at scales much larger than and .
Even without considering the finite size of galaxies, nonzero values for
are generally expected, for instance, for cold dark matter (CDM) models with a
scale-invariant primordial spectrum. For these CDM models, a reasonable force
softening r_s\le 100 \hikpc would have rather tiny effect. We present the CVT
predictions for the small-scale pairwise velocity dispersion in the CDM models
normalized by the COBE observation. The implication of our results for
confrontation of observations of galaxy pair-wise velocity dispersions and
theoretical predictions of the CVT is also discussed.Comment: 18 pages. LaTeX text and 8 postcript figures. submitted to Ap
Relationship between cyclooxygenase-2 and human epidermal growth factor receptor 2 in vascular endothelial growth factor C up-regulation and lymphangiogenesis in human breast cancer
Both cyclooxygenase (COX)-2 and human epidermal growth factor receptor (HER)-2 promote breast cancer progression; however, the relationship between the two molecules remains unclear. We utilized human breast cancer tissues and cell lines to examine whether COX-2 and HER-2 played independent or interdependent roles in vascular endothelial growth factor (VEGF)-C up-regulation and lymphangiogenesis. A paired correlation of immunodetectable levels of COX-2, VEGF-C, and HER-2 proteins and lymphovascular density (LVD; D2-40-immunolabeled) in 55 breast cancer specimens revealed a positive correlation between COX-2 and HER-2 irrespective of clinicopathological status. However COX-2 alone positively correlated with LVD. In 10 independent specimens, mRNA levels showed a positive correlation between HER-2 and COX-2 or VEGF-C but not LYVE-1 (lymphovascular endothelial marker). These findings implicate COX-2, but not HER-2, in breast cancer-associated lymphangiogenesis. Manipulation of the COX-2 or HER-2 genes in breast cancer cell lines varying widely in COX-2 and HER-2 expression revealed a direct role of COX-2 and an indirect COX-2 dependent role of HER-2 in VEGF-C up-regulation: (i) high VEGF-C expression in high COX-2/low HER-2 expressing MDA-MB-231 cells was reduced by siRNA-mediated down-regulation of COX-2, but not HER-2; (ii) integration of HER-2 in these cells simultaneously up-regulated COX-2 protein as well as VEGF-C secretion; and (iii) low VEGF-C secretion by high HER-2/low COX-2 expressing SK-BR-3 cells was stimulated by COX-2 overexpression. These findings of the primary role of COX-2 and the COX-2-dependent role of HER-2, if any, in VEGF-C up-regulation and lymphangiogenesis suggest that COX-2 inhibitors may abrogate lymphatic metastasis in breast cancer irrespective of HER-2 status. © 2010 Japanese Cancer Association
Plasmon reflections by topological electronic boundaries in bilayer graphene
Domain walls separating regions of AB and BA interlayer stacking in bilayer
graphene have attracted attention as novel examples of structural solitons,
topological electronic boundaries, and nanoscale plasmonic scatterers. We show
that strong coupling of domain walls to surface plasmons observed in infrared
nanoimaging experiments is due to topological chiral modes confined to the
walls. The optical transitions among these chiral modes and the band continua
enhance the local ac conductivity, which leads to plasmon reflection by the
domain walls. The imaging reveals two kinds of plasmonic standing-wave
interference patterns, which we attribute to shear and tensile domain walls. We
compute the electronic structure of both wall varieties and show that the
tensile wall contain additional confined bands which produce a
structure-specific contrast of the local conductivity. The calculated plasmonic
interference profiles are in quantitative agreement with our experiments.Comment: 14 pages, 5 figure
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