The Gluon Condensate in Qcd at Finite Temperature

We begin with the discussion of the relationship between the trace of the energy momentum tensor and the gluon condensate at finite temperatures. Using the recent numerical data from the simulations of lattice gauge theory for quantum chromodynamics(QCD) we present the computational evaluations for the gluon condensate. A short discussion of the properties of deconfinement and the implications on the high temperature limit are included. We also mention the case of the massive quarks where some of the properties of the condensate appear to change. We put together these results with some ideas related to the dilatation current. We draw the conclusion that the nature of the strong interactions implies that the thermodynamics of quarks and gluons never approach even at very high temperatures that of an ideal ultrarelativistic gas. PACS numbers:12.38Aw, 11.15Ha, 12.38Mh, 11.40.Dw appeared in Acta Physica Polonica B28, 2937 (1997), corrected version ∗Presented at the XXXVII Cracow School of Theoretical Physics, Zakopane, Poland, May 30-June 10,1997