Godel-type solution in f(R, T) modified gravity

In this paper, we will examine the problem of violation of causality in f(R, T) modified gravity, where R is the Ricci scalar and T is the trace of the energy-momentum tensor T-mu nu. We investigate the causality problem in two special cases, in the first we consider the matter content of the universe as a perfect fluid and in the second case, the matter content is a perfect fluid plus a scalar field.