Modified gravity and cosmology with nonminimal (derivative) coupling between matter and the Einstein tensor

Abstract

We construct new classes of modified theories in which the matter sector couples with the Einstein tensor, namely we consider direct couplings of the latter to the energy-momentum tensor, and to the derivatives of its trace. We extract the general field equations, which do not contain higher-order derivatives, and we apply them in a cosmological framework, obtaining the Friedmann equations, whose extra terms give rise to an effective dark energy sector. At the background level we show that we can successfully describe the usual thermal history of the universe, with the sequence of matter and dark-energy epochs, while the dark-energy equation-of-state parameter can lie in the phantom regime, tending progressively to $-1$ at present and future times. Furthermore, we confront the theory with Cosmic Chronometer data, showing that the agreement is very good. Finally, we perform a detailed investigation of scalar and tensor perturbations, and extracting an approximate evolution equation for the matter overdensity we show that the predicted behavior is in agreement with observations.

9 pages,4 figures, to appear in Phys. Rev. D

References in corpus (19)

• Dynamics of dark energy
• f(R,T) gravity
• Dark torsion as the cosmic speed-up
• Extra force in $f(R)$ modified theories of gravity
• f(R,L_m) gravity
• Cosmological perturbations in f(T) gravity
• Nonminimal coupling of perfect fluids to curvature
• Modified gravity with arbitrary coupling between matter and geometry
• $f(T,\mathcal{T})$ gravity and cosmology
• Teleparallel equivalent of Gauss-Bonnet gravity and its modifications
• Quintessence and phantom cosmology with non-minimal derivative coupling
• Nonminimal torsion-matter coupling extension of f(T) gravity
• Dark Matter From f(R,T) Gravity
• The acceleration of the universe and the physics behind it
• Extended $f(R,L_m)$ gravity with generalized scalar field and kinetic term dependences
• Consequences of a Cosmic Scalar with Kinetic Coupling to Curvature
• Growth factor in $f(T,\mathcal{T})$ gravity
• Some remarks about non-minimally coupled scalar field models
• The growth index of matter perturbations using the clustering of dark energy

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• Weak field and slow motion limits in energy-momentum powered gravity
• Review on the minimally extended varying speed of light model
• The Nature of Dark Energy and Constraints on Its Hypothetical Constituents from Force Measurements
• Nonassicative cosmological solitonic R-flux deformations in gauge gravity and G. Perelman geometric flow thermodynamics
• Neutrino Lorentz invariance violation from the CPT-even SME coefficients through a tensor interaction with cosmological scalar fields