Thermodynamic interpretation of the generalized gravity models with geometry - matter coupling

Abstract

Modified gravity theories with geometry - matter coupling, in which the action is an arbitrary function of the Ricci scalar and the matter Lagrangian ($f\left(R,L_m\right)$ gravity), and of the Ricci scalar and of the trace of the matter energy-momentum tensor ($f(R,T)$ gravity), respectively, have the intriguing property that the divergence of the matter energy - momentum tensor is nonzero. In the present paper, by using the formalism of open thermodynamic systems, we interpret the generalized conservation equations in these gravitational theories from a thermodynamic point of view as describing irreversible matter creation processes, which could be validated by fundamental particle physics. Thus particle creation corresponds to an irreversible energy flow from the gravitational field to the created matter constituents, with the second law of thermodynamics requiring that space-time transforms into matter. The equivalent particle number creation rates, the creation pressure and the entropy production rates are obtained for both $f\left(R,L_m\right)$ and $f(R,T)$ gravity theories. The temperature evolution laws of the newly created particles are also obtained. In the case of the $f(R,T)$ gravity theory the open irreversible thermodynamic interpretation of a simple cosmological model is presented in detail. It is also shown that due to the geometry--matter coupling, during the cosmological evolution a large amount of comoving entropy could be produced.

12 pages, no figures, accepted for publication in PRD; references added. arXiv admin note: text overlap with arXiv:gr-qc/0404045 by other authors without attribution

References in corpus (24)

• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• f(R,T) gravity
• Extra force in $f(R)$ modified theories of gravity
• f(R,L_m) gravity
• Modified-gravity wormholes without exotic matter
• Nonminimal coupling of perfect fluids to curvature
• Modified gravity with arbitrary coupling between matter and geometry
• Generalized curvature-matter couplings in modified gravity
• FRW Cosmology in F(R,T) gravity
• The matter Lagrangian and the energy-momentum tensor in modified gravity with non-minimal coupling between matter and geometry
• Extended $f(R,L_m)$ gravity with generalized scalar field and kinetic term dependences
• New derivation of the Lagrangian of a perfect fluid with a barotropic equation of state
• Matter creation and cosmic acceleration
• Geodesic deviation, Raychaudhuri equation, and tidal forces in modified gravity with an arbitrary curvature-matter coupling
• Is Emergent Universe a Consequence of Particle Creation Process?
• Irreversible thermodynamic description of interacting dark energy - dark matter cosmological models
• Gravitationally Induced Particle Production: Thermodynamics and Kinetic Theory
• Covariant equations of motion for test bodies in gravitational theories with general nonminimal coupling
• Conservation laws in gravitational theories with general nonminimal coupling
• Can primordial magnetic fields be the origin of the BICEP2 data?
• Is the continuous matter creation cosmology an alternative to $\Lambda$CDM?
• Hawking Radiation as a Mechanism for Inflation
• Continuous matter creation and the acceleration of the universe: the growth of density fluctuations
• Constraints on Bose-Einstein-condensed Axion Dark Matter from The HI Nearby Galaxy Survey data

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• Big Bang Nucleosynthesis and Entropy Evolution in $f(R,T)$ Gravity
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• An exponential shape function for wormholes in modified gravity
• A dynamical system representation of generalized Rastall gravity
• Investigating the Physical Properties of Traversable Wormholes in the Modified $f(R,T)$ Gravity
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• Phantom energy supported wormhole model in $f(R,T)$ gravity assuming conformal motion
• Quintessence-like features in the late-time cosmological evolution of $f(Q)$ symmetric teleparallel gravity
• Friedmann equations from nonequilibrium thermodynamics of the Universe: A unified formulation for modified gravity
• Degeneracy between CCDM and $\Lambda$CDM cosmologies
• Reheating and particle creation in unimodular f(R, T) gravity
• Horizon thermodynamics in holographic cosmological models with a power-law term
• Superconducting dark energy
• The Reconstruction of Constant Jerk Parameter with $f(R,T)$ Gravity in Bianchi-I spacetime
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• Entropy production due to adiabatic particle creation in a holographic dissipative cosmology
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• On the correspondence between energy conservation and energy-momentum tensor conservation in cosmology
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• Cosmological sudden singularities in $f(R,T)$ gravity