2011/10/19 by Leonardo Giusti, Giusti, Leonardo
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Theory (hep-th) #hep-lat #hep-th
paper · pdf · doi:10.48550/arxiv.1110.4239
7 pages, 1 figure, contribution to the proceedings of the XXIX International Symposium on Lattice Field Theory - Lattice 2011
arxiv created 2011/10/19 · arxiv updated 2011/10/20
At finite temperature the distribution of the total momentum is an observable characterizing the thermal state of a field theory, and its cumulants are related to thermodynamic potentials. In a relativistic system at zero chemical potential, for instance, the thermal variance of the total momentum is a direct measure of the entropy. We relate the generating function of the cumulants to the ratio of a path integral with properly shifted boundary conditions in the compact direction over the ordinary partition function. In this form it is well suited for Monte-Carlo evaluation, and the cumulants can be extracted straightforwardly. We test the method in the SU(3) Yang--Mills theory, and obtain the entropy density at three different temperatures.