HIGH-TEMPERATURE RESPONSE FUNCTIONS AND THE NON-ABELIAN KUBO FORMULA

We describe the relationship between time-ordered and retarded respons e functions in a plasma. We obtain an expression, including the proper iepsilon prescription, for the induced current due to hard thermal lo ops in a non-Abelian theory, thus giving the non-Abelian generalizatio n of the Kubo formula. The result is closely related to the eikonal fo r a Chern-Simons theory and is relevant for a gauge-invariant descript ion of Landau damping in the quark-gluon plasma at high temperature.