Reversible and Irreversible Spacetime Thermodynamics for General Brans-Dicke Theories

Details Reversible and Irreversible Spacetime Thermodynamics for General Brans-Dicke Theories Reversible and Irreversible Spacetime Thermodynamics for General Brans-Dicke Theories

2010-11-05

arxiv.org/abs/1011.1405v3

Phys.Rev.D83:024032,2011

Astronomy and Astrophysics

Astrophysics

General Relativity and Quantum Cosmology

12 pages, 1 figure; v2: minor editing to clarify Section III, fixed typos; v3: fixed typos

Scientific paper

10.1103/PhysRevD.83.024032

We derive the equations of motion for Palatini F(R) gravity by applying an entropy balance law T dS= \delta Q+\delta N to the local Rindler wedge that can be constructed at each point of spacetime. Unlike previous results for metric F(R), there is no bulk viscosity term in the irreversible flux \delta N. Both theories are equivalent to particular cases of Brans-Dicke scalar-tensor gravity. We show that the thermodynamical approach can be used ab initio also for this class of gravitational theories and it is able to provide both the metric and scalar equations of motion. In this case, the presence of an additional scalar degree of freedom and the requirement for it to be dynamical naturally imply a separate contribution from the scalar field to the heat flux \delta Q. Therefore, the gravitational flux previously associated to a bulk viscosity term in metric F(R) turns out to be actually part of the reversible thermodynamics. Hence we conjecture that only the shear viscosity associated with Hartle-Hawking dissipation should be associated with irreversible thermodynamics.

Affiliated with

Also associated with

No associations

Rating

Reversible and Irreversible Spacetime Thermodynamics for General Brans-Dicke Theories does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Reversible and Irreversible Spacetime Thermodynamics for General Brans-Dicke Theories, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reversible and Irreversible Spacetime Thermodynamics for General Brans-Dicke Theories will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-454822