Hybrid modified gravity unifying local tests, galactic dynamics and late-time cosmic acceleration

Abstract

The non-equivalence between the metric and Palatini formalisms of $f(R)$ gravity is an intriguing feature of these theories. However, in the recently proposed hybrid metric-Palatini gravity, consisting of the superposition of the metric Einstein-Hilbert Lagrangian with an $f(\mathcal{R})$ term constructed à la Palatini, the "true" gravitational field is described by the interpolation of these two non-equivalent approaches. The theory predicts the existence of a light long-range scalar field, which passes the local constraints and affects the galactic and cosmological dynamics. Thus, the theory opens new possibilities for a unified approach, in the same theoretical framework, to the problems of dark energy and dark matter, without distinguishing a priori matter and geometric sources, but taking their dynamics into account under the same standard.

8 pages. Received an Honorable Mention in the Gravity Research Foundation Essay Contest 2013. V2: references added; version to appear in the International Journal of Modern Physics D

References in corpus (14)

• Dynamics of dark energy
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• f(R,T) gravity
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• Extra force in $f(R)$ modified theories of gravity
• Palatini Approach to Modified Gravity: f(R) Theories and Beyond
• f(R,L_m) gravity
• Further matters in space-time geometry: $f(R,T,R_{\mu \nu }{T}^{\mu \nu })$ gravity
• Nonminimal coupling of perfect fluids to curvature
• Wormholes supported by hybrid metric-Palatini gravity
• Do f(R) theories matter?
• Palatini formulation of modified gravity with a nonminimal curvature-matter coupling
• Unifying Einstein and Palatini gravities
• Geodesic deviation, Raychaudhuri equation, and tidal forces in modified gravity with an arbitrary curvature-matter coupling

Cited by in corpus (59)

• Modified Gravity Theories on a Nutshell: Inflation, Bounce and Late-time Evolution
• $f(Q,T)$ gravity
• Extended Gravity Cosmography
• Generalized curvature-matter couplings in modified gravity
• Generalized energy conditions in Extended Theories of Gravity
• Hybrid metric-Palatini gravity
• Palatini formulation of $f(R,T)$ gravity theory, and its cosmological implications
• Selected topics in scalar-tensor theories and beyond
• Generalizing the coupling between geometry and matter: $f(R,L_m,T)$ gravity
• Wormholes in generalized hybrid metric-Palatini gravity obeying the matter null energy condition everywhere
• Geodesic deviation, Raychaudhuri equation, Newtonian limit, and tidal forces in Weyl-type $f(Q,T)$ gravity
• Cosmological solutions in generalized hybrid metric-Palatini gravity
• A dynamical system analysis of hybrid metric-Palatini cosmologies
• Invariant solutions and Noether symmetries in Hybrid Gravity
• Beyond Einstein's General Relativity: Hybrid metric-Palatini gravity and curvature-matter couplings
• Hybrid metric-Palatini stars
• Crossing SNe Ia and BAO observational constraints with local ones in hybrid metric-Palatini gravity
• Probing hybrid modified gravity by stellar motion around Galactic Centre
• Dynamics of Linear Perturbations in the hybrid metric-Palatini gravity
• Born-Infeld-$f(R)$ gravity
• Constraints on hybrid metric-Palatini models from background evolution
• Cosmology in scalar-tensor $f(R,T)$ gravity
• Double gravitational layer traversable wormholes in hybrid metric-Palatini gravity
• Non-minimal geometry-matter couplings in Weyl-Cartan space-times: $f(R,T,Q,T_m)$ gravity
• Screening mechanisms in hybrid metric-Palatini gravity
• Spherically symmetric static vacuum solutions in hybrid metric-Palatini gravity
• Dynamic wormhole geometries in hybrid metric-Palatini gravity
• Estimating the Parameters of Extended Gravity Theories with the Schwarzschild Precession of S2 Star
• Spherically symmetric black holes and wormholes in hybrid metric-Palatini gravity
• Scalar modes in extended hybrid metric-Palatini gravity: weak field phenomenology
• Thick brane structures in generalized hybrid metric-Palatini gravity
• Gravitational Landau Damping for massive scalar modes
• Hybrid metric-Palatini gravity: black holes, wormholes, singularities and instabilities
• Swampland conjectures in hybrid metric-Palatini gravity
• Extended Theories of Gravity with Generalized Energy Conditions
• Constraints on decaying early modified gravity from cosmological observations
• Homogeneous Gödel-type solutions in hybrid metric-Palatini gravity
• Cosmic stringlike objects in hybrid metric-Palatini gravity
• Sudden singularities in generalized hybrid metric-Palatini cosmologies
• Estimating the parameters of Hybrid Palatini gravity model with the Schwarzschild precession of S2, S38 and S55 stars: case of bulk mass distribution
• Weak-field regime of the generalized hybrid metric-Palatini gravity
• Black Hole Perturbations and Quasinormal Modes in Hybrid Metric-Palatini Gravity
• Static spherically symmetric three-form stars
• Wheeler-DeWitt equation and Lie symmetries in Bianchi scalar-field cosmology
• Cosmic strings in generalized hybrid metric-Palatini gravity
• Hybrid metric-Palatini brane system
• Spherically symmetric space-times in generalized hybrid metric-Palatini gravity
• Dynamical reconstruction of the $\Lambda$CDM model in hybrid metric-Palatini gravity
• Possible effects of Hybrid Gravity on stellar kinematics in elliptical galaxies
• Constrained transit cosmological models in $f(R,L_m,T)$-gravity
• Novel electrically charged wormhole, black hole and black bounce exact solutions in hybrid metric-Palatini gravity
• Propagation of quantum particles in Brans-Dicke spacetime. The case of Gamma Ray Bursts
• Modified Gravity with Nonminimal Curvature-Matter Couplings: A Framework for Gravitationally Induced Particle Creation
• Evolving Wormholes in a Cosmological Background
• Geodesic deviation equation in generalized hybrid Metric-Palatini gravity
• Gravitational wave propagation in generalized hybrid metric-Palatini gravity
• Horizons, throats and bounces in hybrid metric-Palatini gravity with a non-zero potential
• Gödel-type solutions in hybrid metric-Palatini gravity
• Cosmological sudden singularities in $f(R,T)$ gravity