Extended $f(R,L_m)$ gravity with generalized scalar field and kinetic term dependences

Abstract

We generalize previous work by considering a novel gravitational model with an action given by an arbitrary function of the Ricci scalar, the matter Lagrangian density, a scalar field and a kinetic term constructed from the gradients of the scalar field, respectively. The gravitational field equations in the metric formalism are obtained, as well as the equations of motion for test particles, which follow from the covariant divergence of the stress-energy tensor. Specific models with a nonminimal coupling between the scalar field and the matter Lagrangian are further explored. We emphasize that these models are extremely useful for describing an interaction between dark energy and dark matter, and for explaining the late-time cosmic acceleration.

5 pages, no figures; the expression for the divergence of the energy-momentum tensor has been corrected; references added; minor modifications, accepted for publication in PRD

References in corpus (20)

• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• f(R,T) gravity
• The Standard Model Higgs boson as the inflaton
• Extra force in $f(R)$ modified theories of gravity
• f(R,L_m) gravity
• Nonminimal coupling of perfect fluids to curvature
• Modified gravity with arbitrary coupling between matter and geometry
• Equivalence Principle Violations and Couplings of a Light Dilaton
• Growing Matter
• The matter Lagrangian and the energy-momentum tensor in modified gravity with non-minimal coupling between matter and geometry
• Growing neutrinos and cosmological selection
• A viability criterion for modified gravity with an extra force
• Brans-Dicke Scalar Field as a Chameleon
• New derivation of the Lagrangian of a perfect fluid with a barotropic equation of state
• Galactic rotation curves in modified gravity with non-minimal coupling between matter and geometry
• Palatini formulation of modified gravity with a nonminimal curvature-matter coupling
• The viability of theories with matter coupled to the Ricci scalar
• Motion of test bodies in theories with nonminimal coupling
• Non-minimally coupled f(R) Cosmology
• Dark matter from dark energy-baryonic matter couplings

Cited by in corpus (8)

• f(R,T) gravity
• $f(T,\mathcal{T})$ gravity and cosmology
• Generalized curvature-matter couplings in modified gravity
• Thermodynamic interpretation of the generalized gravity models with geometry - matter coupling
• On the consistency of universally non-minimally coupled $f(R,T,R_{\mu \nu }{T}^{\mu \nu })$ theories
• Dynamical features of scalar-torsion theories
• Breaking of the equivalence principle in the electromagnetic sector and its cosmological signatures
• Late-time cosmology of scalar-tensor theories with universal multiplicative coupling between the scalar field and the matter Lagrangian