Energy conditions and stability inf(R)theories of gravity with nonminimal coupling to matter

Abstract

Recently, in the context of f (R) modified theories of gravity, a new type of model has been proposed where one directly couples the scalar curvature to matter. As any model in f (R) theory, there are certain conditions which have to be satisfied in order to ensure that the model is viable and physically meaningful. In this paper, one considers this new class of models with curvature-matter coupling and study them from the point of view of the energy conditions and of their stability under the Dolgov-Kawasaki criterion.PACS numbers: 04.50. Kd, 98.80.Jk

Energy conditions in modified f(G) gravity

“…Some of the literature review of ECs were discussed by using the classical ECs of general relativity (GR) like the phantom fields potential [46], the history of expanding universe [47][48][49][50][51][52] and the pattern movement of deceleration parameters [53,54]. The various expression for ECs are derived in f (R) gravity [55] and using these formalism and techniques, some authors have pointed out some issues (cosmological) in f (R) gravity [56][57][58]. The general formalism for ECs are derived in f (G) gravity by García et al [59].…”

Traversable wormholes and time machines in nonminimally coupled curvature-matterf(R)theories

“…In a theory with nonminimal curvature-matter coupling, the energy conditions were studied in Ref. [20] and the condition to have wormhole solutions translates into T ef f µν k µ k ν < 0 as follow from Eq. (4).…”

Energy conditions in f(T) gravity with higher-derivative torsion terms

“…As the figure shows, the WEC is satisfied in the specific form of Equ. (25) for a suitable choice of the subspaces of the model parametric space.…”

“…In the literature, this approach has been extensively studied to evaluate the possible ranges of the free parameter of the generalized gravity models. For instants, the energy bound have been explored to constrain f (R) theories of gravity [21][22][23][24] and some extensions of f (R) gravity [25][26][27][28][29][30][31][32][33], modified Gauss-Bonnet gravity [34][35][36][37] and scalar-tensor gravity [38,39]. The energy condition have also been analysed in f (T ) gravity [40][41][42] and generalized models of f (T ) gravity [43][44][45][46].…”