Solutions for the MaxEnt problem with symmetry constraints

In this paper, we deal with the situation in which the unknown state of a quantum system has to be estimated under the assumption that it is prepared obeying a known set of symmetries. We present a system of equations and an explicit solution for the problem of determining the MaxEnt state satisfying these constraints. Our approach can be applied to very general situations, including symmetries of the source represented by Lie and finite groups.