Transport coefficients from the lattice?*

The prospects of extracting transport coefficients from euclidean lattice simulations are discussed. Some general comments on the reconstruction of spectral functions using the Maximal Entropy Method are given as well. 1. In field theory transport coefficients are pro-portional to the slope of appropriate spectral functions at zero frequency and zero spatial mo-mentum (Kubo relation). Examples are the elec-trical conductivity, (1) where pem(x, Y) = ([am,,&,]) is the spec-tral function associated with the electromagnetic current j & = 7j$$, and the shear viscosity, (2) where ~~~(5, Y) = ([u(x), W(Y)]) with m the traceless part of the spatial energy-momentum tensor