A Lagrangian description of interacting dark energy

Abstract

We propose a relativistically covariant model of interacting dark energy based on the principle of least action. The cosmological term $\Lambda$ in the gravitational Lagrangian is a function of the trace of the energy--momentum tensor $T$. We find that the $\Lambda (T)$ gravity is more general than the Palatini $f(R)$ gravity, and reduces to the latter if we neglect the pressure of matter. We show that recent cosmological data favor a variable cosmological constant and are consistent with the $\Lambda (T)$ gravity, without knowing the specific function $\Lambda (T)$.

14 pages; corrected errors, added comments

Cited by in corpus (5)

• Generalized curvature-matter couplings in modified gravity
• Cosmology in scalar-tensor $f(R,T)$ gravity
• Low redshift constraints on energy-momentum-powered gravity models
• Holographic dark energy reconstruction of $f(T,\mathcal{T})$ gravity
• Models of Collapsing and Expanding Cylindrical Source in f(R,T) Theory