Riemann solitons on perfect fluid spacetimes in f(r, T)-gravity

This research paper attempts to study almost Riemann solitons and almost gradient Riemann solitons on perfect fluid spacetimes in f(r, T)-gravity. At first, we obtain divergence of potential vector field of a almost Riemann soliton in terms of scalar curvature on a perfect fluid spacetime in f(r, T)-gravity. Also, we discuss almost Riemann solitons on some special types of perfect fluid spacetimes in f(r, T)-gravity such as dark fluid, dust fluid, and radiation type.