Abstract:
Bulk viscosity is an important transport coefficient that exists in the
hydrodynamical limit only when the underlying theory is non-conformal. One example being thermal QCD with large number of colors. We study bulk viscosity in
such a theory at low energies and at weak and strong ’t Hooft couplings when the
temperature is above the deconfinement temperature. The weak coupling analysis is
based on Boltzmann equation from kinetic theory whereas the strong coupling analysis uses non-conformal holographic techniques from string and M-theories. Using
these, many properties associated with bulk viscosity may be explicitly derived. This
is a shortened companion paper that summarizes some of the results of our longer
paper [1] .
