7 papers
There is no local chiral perturbation theory at finite temperature
Stefan Leupold
For a low-temperature expansion in QCD it is well-known that the Lagrangian of vacuum chiral perturbation theory can be applied. This is due to the fact that the thermal effects of…
Gauge covariant heat kernel expansion at finite temperature
Stefan Leupold
The heat kernel method is extended to the case of finite temperature. Special emphasis is given to the study of gauge theories. Due to the compactness of space in the Euclidean tim…
Spectral Functions of Quarks in Quark Matter
Frank Froemel, Stefan Leupold, Ulrich Mosel
We present a simple albeit self-consistent approach to the spectral function of light quarks in infinite quark matter. Relations between correlation functions and collision rates a…
Determination of vector meson properties by matching resonance saturation to a constituent quark model
Stefan Leupold
The properties of mesonic resonances can be calculated in terms of the low-energy coefficients of chiral perturbation theory (chiPT) by extending unitarized chiPT to higher energie…
Stochastic interpretation of Kadanoff-Baym equations
Carsten Greiner, Stefan Leupold
We show that the nonperturbative transport equations, the so called `Kadanoff-Baym equations', within the non-equilibrium real time Green's function description can be be understoo…
Resummation of soft modes in the free energy of Phi^4 theory
Stefan Leupold
A new method is proposed for the calculation of the free energy of an N-component Phi^4 theory at finite temperature. The method combines a perturbative treatment of the hard modes…