First-order thermodynamics of Horndeski cosmology
We delve into the first-order thermodynamics of Horndeski gravity, focusing on spatially flat,
homogeneous, and isotropic cosmologies. Our exploration begins with a comprehensive …
homogeneous, and isotropic cosmologies. Our exploration begins with a comprehensive …
First-order thermodynamics of Horndeski gravity
We extend to the Horndeski realm the irreversible thermodynamics description of gravity
previously studied in “first generation” scalar-tensor theories. We identify a subclass of …
previously studied in “first generation” scalar-tensor theories. We identify a subclass of …
First-order thermodynamics of scalar-tensor cosmology
A new thermodynamics of scalar-tensor gravity is applied to spatially homogeneous and
isotropic cosmologies in this class of theories and tested on analytical solutions. A forever …
isotropic cosmologies in this class of theories and tested on analytical solutions. A forever …
Scalar field as a perfect fluid: thermodynamics of minimally coupled scalars and Einstein frame scalar-tensor gravity
We revisit the analogy between a minimally coupled scalar field in general relativity and a
perfect fluid, correcting previous identifications of effective temperature and chemical …
perfect fluid, correcting previous identifications of effective temperature and chemical …
More on the first-order thermodynamics of scalar-tensor and Horndeski gravity
V Faraoni, J Houle - The European Physical Journal C, 2023 - Springer
Two issues in the first-order thermodynamics of scalar-tensor (including “viable” Horndeski)
gravity are elucidated. The application of this new formalism to FLRW cosmology is shown to …
gravity are elucidated. The application of this new formalism to FLRW cosmology is shown to …
Stealth metastable state of scalar-tensor thermodynamics
V Faraoni, TB Françonnet - Physical Review D, 2022 - APS
We investigate a puzzle in the recent thermodynamics of scalar-tensor gravity, in which
general relativity is a zero-temperature state of equilibrium and scalar-tensor gravity is the …
general relativity is a zero-temperature state of equilibrium and scalar-tensor gravity is the …
Peculiar thermal states in the first-order thermodynamics of gravity
In the context of the recently proposed first-order thermodynamics of scalar-tensor gravity,
we discuss the possibility of zero-temperature states of equilibrium other than Einstein …
we discuss the possibility of zero-temperature states of equilibrium other than Einstein …
Thermal stability of stealth and de Sitter spacetimes in scalar-tensor gravity
Stealth solutions of scalar-tensor gravity and less-known de Sitter spaces that generalize
them are analyzed regarding their possible role as thermal equilibria at non-zero …
them are analyzed regarding their possible role as thermal equilibria at non-zero …
Disforming scalar-tensor cosmology
V Faraoni, C Zeyn - Physical Review D, 2024 - APS
Disformal transformations of Friedmann-Lemaître-Robertson-Walker and Bianchi
geometries are analyzed in the context of scalar-tensor gravity. Novel aspects discussed …
geometries are analyzed in the context of scalar-tensor gravity. Novel aspects discussed …
Past-directed scalar field gradients and scalar-tensor thermodynamics
We refine and slightly enlarge the recently proposed first-order thermodynamics of scalar-
tensor gravity to include gravitational scalar fields with timelike and past-directed gradients …
tensor gravity to include gravitational scalar fields with timelike and past-directed gradients …