f(R, T, R_\mu\nu T^\mu\nu) gravity phenomenology and \Lambda CDM universe

TL;DR

This paper introduces a generalized gravity theory involving functions of curvature and matter tensors, explores its cosmological implications including DM universe reconstruction, and discusses stability issues.

Contribution

It presents a new generalized f(R,T,R_{}T^{}) gravity model, analyzes its cosmological solutions, and explicitly reconstructs actions compatible with DM universe.

Findings

Reconstruction of the DM universe within the new gravity model.

Existence of de Sitter solutions with non-constant fluid.

Discussion of matter instability problems in the theory.

Abstract

We propose general f(R,T,R_{\mu\nu}T^{\mu\nu}) theory as generalization of covariant Horava-like gravity with dynamical Lorentz symmetry breaking. FRLW cosmological dynamics for several versions of such theory is considered. The reconstruction of the above action is explicitly done, including the numerical reconstruction for the occurrence of \Lambda CDM universe. De Sitter universe solutions in the presence of non-constant fluid are also presented. The problem of matter instability in f(R,T,R_{\mu\nu}T^{\mu\nu}) gravity is discussed.