Thermodynamics in hybrid metric-Palatini gravity

Abstract

We study the thermodynamic behavior of a hybrid metric-Palatini gravity, which consists of adding to the Einstein-Hilbert Lagrangian a f (R) term constructed within the framework of the Palatini formalism. Using the respective dynamically equivalent scalar tensor representation, we investigate the verification of the first law and the generalized second law (GSL) of thermodynamics on the dynamically apparent horizon. We also examine the validity of the GSL in a universe bounded by the cosmological event horizon filled with the perfect fluid in this modified gravity theory.

Thermodynamics in f(T) Gravity with Nonminimal Coupling to Matter

“…However, it has been demonstrated in [29] that it is possible to obtain an equilibrium description of thermodynamics on the apparent horizon of ( ) gravity. The same works also have been carried out in ( ) gravity [40] and some extended models of ( ) gravity [29,37]. In addition to the first law of thermodynamics, there has been a lot of interest in exploring the second law of thermodynamics in gravitational theories [46][47][48][49][50][51][52][53][54].…”

“…This approach soon generalized to the cosmological situation, where it was shown that, by applying the Clausius relation to the apparent horizon of the Friedmann-Robertson-Walker (FRW) universe, the Friedmann equation can be rewritten in the form of the first law of thermodynamics [21]. Recently, the equivalence of the Clausius relation and the gravitational field equations has been investigated to the more general modified theories of gravity such as Gauss-Bonnet gravity [22], Lovelock gravity [23,24], Braneworld gravity [25], scalar-tensor gravity [26], ( ) theories [27][28][29][30][31], and the extended models of ( )-gravity [32][33][34][35][36][37]. In the context of ( ) gravity, the first law of black hole thermodynamics has been studied in [38] and the thermodynamics of the apparent horizon of the FRW universe is explored in [39][40][41].…”

Homogeneous Gödel-type solutions in hybrid metric-Palatini gravity

“…Thus, taking into account equations (35), (37), (39) and (44), one has that for the combined-fields matter source (36) the field equations (34) reduce to…”

“…Wormwhole solutions, Einstein static universe, linear perturbations, the Cauchy problem, dynamical system analysis and a brane model have been discussed, respectively, in the references [30,31,32,33,34,35]. Other important matters such as Noether symmetries [36] and the thermodynamic behavior [37] have also been recently considered. For an introduction to hybrid metric-Palatini f (R) gravity and a detailed list of related references, we refer the reader to the recent review article [28].…”

Screening mechanisms in hybrid metric-Palatini gravity

“…Such results have motivated a number of analyses on this class of theories. Cosmological consequences of the so-called hybrid metric-Palatini gravity, including criteria to obtain cosmic acceleration [20], dynamical solutions [21], the dark matter problem [22], among others [23][24][25][26][27], have been investigated. However, the main conceptual reason for introducing hybrid gravity is the following.…”