Cutoff effects on energy-momentum tensor correlators in lattice gauge theory

We investigate the discretization errors affecting correlators of the energy-momentum tensor T-mu nu at finite temperature in SU(N-c) gauge theory with the Wilson action and two different discretizations of T-mu nu. We do so by using lattice perturbation theory and non-perturbative Monte-Carlo simulations. These correlators, which are functions of Euclidean time x(0) and spatial momentum p, are the starting point for a lattice study of the transport properties of the gluon plasma. We find that the correlator of the energy integral d(3) x T-00 has much larger discretization errors than the correlator of momentum integral d(3) x T-0k. Secondly, the shear and diagonal stress correlators (T-12 and T-kk) require N-tau >= 8 for the T-x0 = 1/2 point to be in the scaling region and the cutoff effect to be less than 10%. We then show that their discretization errors on an anisotropic lattice with a alpha/a tau = 2 are comparable to those on the isotropic lattice with the same temporal lattice spacing. Finally, we also study finite p correlators.