Concerning the microscopic linear response theory

We present a procedure for dealing with the fluctuation-dissipation theorem (Kubo) without using Liouville-Neumann phase-space evolution. Thus, our pr ocedure clarifies some objections posed against microscopic linear-response theory. As an application of our method, we revisit the calculation of the electric conductivity, in particular emphasis is made to establish the val idity of the Greenwood-Peierls DC-conductivity when compared with the funda mental Kubo's formula. (C) 2001 Elsevier Science B.V. All rights reserved.