Davies Critical Point and Tunneling

TL;DR

This paper clarifies the physical significance of the Davies critical point in black hole thermodynamics, showing it marks a transition where black hole radiation shifts from nonthermal to purely thermal, across various black hole types.

Contribution

It provides a detailed analysis of the Davies critical point's meaning in tunneling perspective and explores phase transitions in charged and rotating black holes including charge and angular momentum emissions.

Findings

At the critical point, black hole radiation becomes purely thermal.

The Davies critical point separates phases with enhanced and suppressed nonthermal radiation.

Phase transition behavior is consistent across charged and rotating black holes.

Abstract

From the point of view of tunneling, the physical meaning of the Davies critical point of a second order phase transition in the black hole thermodynamics is clarified. At the critical point, the nonthermal contribution vanishes so that the black hole radiation is entirely thermal. It separates two phases: one with radiation enhanced by the nonthermal contribution, the other suppressed by the nonthermal contribution. We show this in both charged and rotating black holes. The phase transition is also analyzed in the cases in which emissions of charges and angular momenta are incorporated.