Past-directed scalar field gradients and scalar-tensor thermodynamics

Abstract

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. The implications and subtleties arising in this situation are discussed and an exact cosmological solution of scalar-tensor theory in first-order thermodynamics is revisited in light of these results.

7 pages, no figures

References in corpus (16)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
• Horndeski theory and beyond: a review
• The Expansion of the Universe is Faster than Expected
• Black Holes in Bi-scalar Extensions of Horndeski Theories
• Time-dependent spherically symmetric covariant Galileons
• Cosmological self-tuning and local solutions in generalized Horndeski theories
• Hairy black holes in DHOST theories: Exploring disformal transformation as a solution-generating method
• First-order thermodynamics of scalar-tensor cosmology
• Scalar field as a perfect fluid: thermodynamics of minimally coupled scalars and Einstein frame scalar-tensor gravity
• Fluid nature constrains Horndeski gravity
• Peculiar thermal states in the first-order thermodynamics of gravity
• Disformal mappings of spherical DHOST geometries
• New time-dependent solutions of viable Horndeski gravity
• Stealth metastable state of scalar-tensor thermodynamics

Cited by in corpus (7)

• Scalar field as a perfect fluid: thermodynamics of minimally coupled scalars and Einstein frame scalar-tensor gravity
• More on the first-order thermodynamics of scalar-tensor and Horndeski gravity
• First-order thermodynamics of scalar-tensor gravity
• Alternative formulations of the thermodynamics of scalar-tensor theories
• Eckart heat-flux applicability in $F(\Phi ,X)R$ theories and the existence of temperature gradients
• No-Go Theorems for Hairy Black Holes in Scalar- or Vector-Tensor-Gauss-Bonnet Theory
• Thermal description of braneworld effective theories