English

Varying alpha and black hole entropy

High Energy Physics - Theory 2009-11-07 v2 Astrophysics General Relativity and Quantum Cosmology High Energy Physics - Phenomenology

Abstract

Recently it has been suggested that an increase in the fine structure constant alpha with time would decrease the entropy of a Reissner-Nordstrom black hole, thereby violating the second law of thermodynamics. In this note we point out that, at least for a certain class of charged dilaton black holes related to string theory, the entropy does not change under adiabatic variations of alpha and one might expect it to increase for non-adiabatic changes.

Keywords

Cite

@article{arxiv.hep-th/0212105,
  title  = {Varying alpha and black hole entropy},
  author = {Malcolm Fairbairn and Michel H. G. Tytgat},
  journal= {arXiv preprint arXiv:hep-th/0212105},
  year   = {2009}
}

Comments

5 pages, matches version accepted in JHEP

R2 v1 2026-07-22T15:14:40.038Z