We review the various methods which have been employed recently to describe the thermodynamics of the high temperature quark-gluon plasma using weak coupling techniques, and we compare their results with those of most recent lattice gauge calculations. Many of the difficulties encountered with perturbation theory at finite temperature are in fact not specific to QCD but are present in any field...

We rederive the finite size scaling formula for the apparent critical temperature by using Mean Field Theory for the Ising Model above the upper critical dimension. We have also performed numerical simulations in five dimensions and our numerical data are in a good agreement with the Mean Field theoretical predictions, in particular, with the finite size exponent of the connected susceptibility...

In these lectures, I will attempt a pedagogical and qualitative introduction to the theory of equilibrium and thermalization of quark-gluon plasmas. I assume only that the reader is familiar with quantum field theory at zero temperature and with QCD as the theory of the strong interactions. I focus on the limit of small αs, which in principle should be relevant at extremely high temperature bec...

Flash sintering is one of the newest techniques for sintering ceramics to near full density. It occurs in an appropriate combination of temperature and electric field. Temperature measurement is one of the most serious challenges in this process. In the present study, we tried to model a flash sintering process of 8YSZ and 3YSZ with finite element method to make an assessment for temperature di...

We revisited the calculation of the effective potential for self-interacting scalar field with U (1) charge at one loop approximation. We show that high charge densities can induce important changes in the phase structure of the theory. A class of very interesting phenomena appear when we introduce finite density effects, e.g. symmetry nonrestoration, inverse symmetry breaking and anticipation ...

By solving the gap equation in the quenched, ladder approximation for an Abelian gauge model with Yukawa interaction in the presence of a constant magnetic field, we show that the Yukawa interactions enhance the dynamical generation of fermion mass. The theory is then studied at finite temperature, where we prove that the critical magnetic field, required for the mass generation to be important...

There is a number of interesting scenarios which are described by quantum field theories at finite temperature (electroweak phase transition, heavy ion collisions, etc.) In this talk I will focus on the deconfinement phase transition of QCD: lattice simulations suggest that hadron matter undergoes a transition into a phase in which quarks are deconfined at a temperature of order 150 MeV. This n...

Global conformal invariance (GCI) of quantum field theory (QFT) in two and higher space–time dimensions implies the Huygens’ principle, and hence, rationality of correlation functions of observable fields [16]. The conformal hamiltonian H has discrete spectrum and we assume that the partition function trD ( q ) , q = e2πi τ , Im τ > 0 (|q| < 1) as well as the finite temperature expectation valu...

After having developed a method that measures real time evolution of quantum systems at a finite temperature, we present here the simplest field theory where this scheme can be applied to, namely the 1 + 1 Ising model. We will compute the probability that if a given spin is up, some other spin will be up after a time t, the whole system being at temperature T . We can thus study spatial correla...