arXiv subjects
Publications and source records attributed to A. Peshier.
The thermodynamical potential of relativistic gauge theories can be consistently resummed in terms of HTL propagators, which is, without being restricted to it, exemplified for the case of hot QED. The nonperturbative resummation is gauge independent, free of thermal divergences and, in the weak-coupling limit, compatible with the leading order perturbative result.
A quasi-particle model is presented which describes QCD lattice results for the 0, 2 and 4 quark-flavor equation of state. The results are mapped to finite baryo-chemical potentials. As an application of the model we make a prediction of deconfined matter with appropriate inclusion of strange quarks and consider pure quark stars.
A quasiparticle description of the thermodynamics of deconfined matter, reproducing both the perturbative limit and nonperturbative lattice QCD data at finite temperature, is generalized to finite chemical potential. By a flow equation resulting from Maxwell's relation, the equation of state is extended from zero to non-zero quark densities. The impact of the massive strange flavor is considered and implications for cold, charge-neutral deconfined matter in $β$-equilibrium in compact stars are given.
An effective quasiparticle description of the thermodynamics of deconfined matter, compatible with both finite-temperature lattice data and the perturbative limit, is generalized to finite chemical potential. Within this approach, the available 4-flavor lattice equation of state is extended to finite baryon density, and implications for cold, charge-neutral deconfined matter in beta-equilibrium in compact stars are considered.
An effective quasiparticle description of deconfined QCD thermodynamics compatible with both finite temperature nonperturbative lattice data and the asymptotic limit is generalized to finite chemical potential. Implications for the N_f = 4 flavor lattice data extended to mu \neq 0 as well as for deconfined matter with realistic quark masses are considered.
Relying on the Luttinger-Ward theorem we derive a thermodynamically selfconsistent and scale independent approximation of the thermodynamic potential for the scalar $ϕ^4$ theory in the tadpole approximation. The resulting thermodynamic potential as a function of the temperature is similar to the one of the recently proposed screened perturbation theory.
The complete one-loop self energies (real and imaginary parts) for photons, gluons, electrons and quarks at finite temperature are calculated numerically and compared to the results of the hard thermal loop (HTL) approximation used for the resummation technique of Braaten and Pisarski. In this way some light is shed on the validity of the weak coupling limit assumption ($g \ll 1$) or equivalently the high temperature assumption, on which the HTL approximation is based. Furthermore, the gauge dependence of the fermion self energy beyond the HTL approximation is considered. Finally the dispersion relations following from the real part of the self energies are compared to the HTL results.