10,233 research outputs found

    Diffeomorphism on Horizon as an Asymptotic Isometry of Schwarzschild Black Hole

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    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 ν=5/2\nu = 5/2

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    A modest in-plane magnetic field \Bpar\ is sufficient to destroy the fractional quantized Hall states at ν=5/2\nu = 5/2 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 ν=1/2\nu = 1/2. 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 ν=5/2\nu = 5/2 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

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    We report the results of an analysis of the redshift power spectrum PS(k,μ)P^S(k,\mu) in three typical Cold Dark Matter (CDM) cosmological models, where μ\mu 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 PS(k,μ)=PR(k)[1+βμ2]2D(k,μ,σ12(k)), P^S(k,\mu)=P^R(k)[1+\beta\mu^2]^2D(k,\mu,\sigma_{12}(k)), where PR(k)P^R(k) is the real space power spectrum, and β\beta equals Ω00.6/bl\Omega_0^{0.6}/b_l. The damping function DD which should generally depend on kk, μ\mu, and σ12(k)\sigma_{12}(k), is found to be a function of only one variable kμσ12(k)k\mu\sigma_{12}(k). This scaling behavior extends into the nonlinear regime, while DD can be accurately expressed as a Lorentz function - well known from linear theory - for values D>0.1D > 0.1. The difference between σ12(k)\sigma_{12}(k) and the pairwise velocity dispersion defined by the 3-D peculiar velocity of the simulations (taking r=1/kr=1/k) is about 15%. Therefore σ12(k)\sigma_{12}(k) is a good indicator of the pairwise velocity dispersion. The exact functional form of DD depends on the cosmological model and on the bias scheme. We have given an accurate fitting formula for the functional form of DD 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

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    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

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    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 178^{178}Hfm2^{m2} in the constrained relativistic mean field theory

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    The properties of the ground state of 178^{178}Hf and the isomeric state 178^{178}Hfm2^{m2} 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 178^{178}Hf. Using the ground state single-particle eigenvalues obtained in the present calculation, the lowest excitation configuration with Kπ=16+K^\pi=16^+ is found to be ν(7/2[514])1(9/2+[624])1\nu(7/2^-[514])^{-1}(9/2^+[624])^{1} π(7/2+[404])1(9/2[514])1\pi(7/2^+[404])^{-1}(9/2^-[514])^{1}. 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 178^{178}Hfm2^{m2} 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

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    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 rcr_c in the two-point correlation function of mass, i.e. ξρ(r)(r+rc)γ\xi_\rho(r) \propto (r+r_c)^{-\gamma} and the effective gravitational force softening rsr_s on small scales. We analytically obtain the lowest-order correction term for γ<2\gamma <2 which is in quantitative agreement with the full numerical evaluation. With a nonzero rsr_s and/or rcr_c the cosmic virial theorem is no longer limited to the case of γ<2\gamma<2. We present accurate fitting formulae for the CVT predicted pairwise velocity dispersion for the case of γ>2\gamma>2. Compared with the idealistic point-mass approximation (rs=rc=0r_s=r_c=0), the finite size effect can significantly reduce the small-scale velocity dispersions of galaxies at scales much larger than rsr_s and rcr_c. Even without considering the finite size of galaxies, nonzero values for rcr_c 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

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    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

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    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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