Generalized Second Law Limits on the Variation of Fundamental Constants

TL;DR

This paper explores how the Generalized Second Law of Thermodynamics constrains the possible variation of fundamental constants, specifically the fine structure constant, using black hole physics and cosmological data.

Contribution

It establishes a theoretical limit on the variation of the fine structure constant based on black hole thermodynamics and compares it with observational claims.

Findings

The maximum variation matches observed cosmological data.

Black holes cannot respond adiabatically to changes in the fine structure constant.

Theoretical limits align with measured variations.

Abstract

The theoretical maximum time variation in the electronic charge permitted by the Generalized Second Law of Thermodynamics applied to black holes radiating and accreting in the cosmic microwave background matches the measured cosmological variation in the fine structure constant claimed by Webb et al.. Such black holes cannot respond adiabatically to a varying fine structure constant.