Realizations of thermal supersymmetry

We investigate realizations of supersymmetry at finite temperature in terms of thermal superfields, in a thermally constrained superspace: the Grassma nn coordinates are promoted to be time dependent and antiperiodic, with a p eriod given by the inverse temperature. This approach allows us to formulat e a Kubo-Martin-Schwinger (KMS) condition at the level of thermal superfiel d propagators. The latter is proven directly in thermal superspace, and is shown to imply the correct (bosonic and fermionic) KMS conditions for the c omponent fields. In thermal superspace, we formulate thermal covariant deri vatives and supercharges and derive the thermal super-Poincare algebra. Fin ally, we briefly investigate field realizations of this thermal supersymmet ry algebra, focusing on the Wess-Zumino model. The thermal superspace forma lism is used to characterize the breaking of global supersymmetry at finite temperature. (C) 1999 Elsevier Science B.V.