119029155
CHARMONIA AT FINITE MOMENTA IN A DECONFINED PLASMA
Lattice studies of charmonium systems have indicated that in a deconfined gluonic plasma ground state charmonia survive as bound states upto temperatures N 2Tc. After surveying the methodologies used in reaching these results, we examine the behavior of these systems when the bound state is in motion with respect to the heatbath frame. We find that the finite momenta charmonia show medium modifications when the medium is deconfined; in particular, a modification of the energy-momentum dispersion relation is indicated.
16483183
MESON CORRELATION FUNCTIONS AT HIGH TEMPERATURES.
We present preliminary results for the correlation- and spectral functions of different meson channels on the lattice. The main focus lies on gaining control over cut-off as well as on the finite-volume effects. Extrapolations of screening masses above the deconfining temperature are guided by the result of the free (T = {infinity}) case on the lattice and in the continuum. We study the quenched non-perturbatively improved Wilson-clover fermion as well as the hypercube fermion action which might show less cut-off effects.
17426308
Impact of Z2 monopoles and vortices on the deconfinement transition
Abstract Suppressing Z 2 -monopoles shifts the line of deconfinement transitions in the coupling plane of the SU (2) lattice gauge theory with a mixed Villain form of action but it still continues to behave also like the bulk transition line. Separate deconfinement and bulk phase transitions are found on the same lattice, suggesting the two to be indeed coincident at higher adjoint couplings. Universality is restored when both monopoles and vortices are suppressed.
14557202
Phase transitions in SO(3) lattice gauge theory
The phase diagram of SO(3) lattice gauge theory is investigated by Monte Carlo techniques on both symmetric N σ 4 and asymmetric N σ 3 × N β lattices with a view (i) to understanding the relationship between the bulk transition and the deconfinement transition, and (ii) to resolving the current ambiguity about the nature of the high temperature phase. A number of tests, including an introduction of a magnetic field and measurement of different correlation functions in the phases with positive and negative values for the adjoint Polyakov line, L α , lead to the conclusion that the two phases correspond to the same physical state. Studies on lattices of different sizes reveal only one phase transition for this theory on all of them and it appears to have a deconfining nature.
119240200
Properties of the SU(Nc) Gluon Plasma
We investigate the deconfinement transition in SU(Nc) gauge theories, and properties of the deconfined phase. A detailed lattice study of SU(4) and SU(6) gauge theories are conducted, and finite volume and cutoff effects on thermodynamic observables are studied. The scaling of the deconfinement transition point with lattice spacing is used to calculate the scale, Lambda_MSbar. The continuum estimates of the thermodynamic quantities are used to study properties of the gluon plasma. In particular, the approach to conformal limit is studied. We do not find any evidence of a strongly coupled, conformal phase in these theories.
118865781
Meson correlators above deconfinement
We review recent progress in studying spectral functions for mesonic observables at finite temperatures, by analysis of imaginary time correlators directly calculated on isotropic lattices. Special attention is paid to the lattice artefacts present in such calculations.
119252560
Higher spin quasinormal modes and one-loop determinants in the BTZ black hole
A bstractWe solve the wave equations of arbitrary integer spin fields in the BTZ black hole background and obtain exact expressions for their quasinormal modes. We show that these quasinormal modes precisely agree with the location of the poles of the corresponding two point function in the dual conformal field theory as predicted by the AdS/CFT correspondence. We then use these quasinormal modes to construct the one-loop determinant of the higher spin field in the thermal BTZ background. This is shown to agree with that obtained from the corresponding heat kernel constructed recently by group theoretic methods.
119521185
Colors of Luminous Bulges in Cluster MS 1054–03 and Field Galaxies at Redshifts z ~ 0.83*
Using Hubble Space Telescope images, we separate the bulgelike (dubbed "pbulge") and disklike ("pdisk") components of 71 galaxies in the rich cluster MS 1054-03 and of 21 in the field. Our key finding is that luminous pbulges are very red, with rest-frame U-B ~ 0.45, while predicted colors are bluer by 0.20 mag. Moreover, these very red colors appear to be independent of environment, pbulge luminosity, pdisk color, and pbulge fraction. These results challenge any model of hierarchical galaxy formation that predicts the colors of distant (z ~ 0.8) luminous field and cluster bulges will differ. Our findings also disagree with other claims that 30% to 50% of bright bulges and elliptical galaxies at z ~ 1 are very blue (U-B ≤ 0).