Shear viscosity of the classical ${\mathrm{\Phi }}^4$ theory is measured using classical microcanonical simulation. To calculate the Kubo formula, we measure the energy-momentum tensor correlation function and apply the Green-Kubo relation. Given that this is a classical theory, the results depend on the cutoff, which should be chosen in the range of the temperature. Comparison with experimentally accessible systems is also performed.

• Received 4 June 2015

DOI:https://doi.org/10.1103/PhysRevD.92.105011