PUB - Publikationen an der Universität Bielefeld

The lattice data for the energy density of SU(2) gauge theory are calculated with nonperturbative derivatives of the coupling constants. These derivatives are obtained from two sources: (i) a parametrization of the non-perturbative beta function in accord with the measured critical temperature and Delta beta-values and (ii) a non-perturbative calculation of the presssure. We then perform a detailed finite size scaling analysis of the energy density near T-c. It is shown that at the critical temperature the energy density is scaling as a function of VT3 With the corresponding 3D Ising model critical exponents. The value of epsilon(T-c)/T-c(4) in the continuum limit is estimated to be 0.256(23). In the high temperature regime the energy density is approaching its weak coupling limit from below, at T/T-c approximate to 2 it has reached only about 70% of the limit.