Particle creation rate for dynamical black holes

TL;DR

This paper derives a new frequency cutoff for Hawking radiation in dynamical black holes using quantum fluctuations and applies it to a Vaidya model, revealing conditions under which Hawking radiation is suppressed or persists.

Contribution

It introduces a novel ultraviolet frequency cutoff based on quantum fluctuations and applies it to dynamical black holes, providing insights into their radiation emission and growth.

Findings

Hawking radiation persists in slowly evolving dynamical black holes.

The frequency cutoff can suppress Hawking radiation under certain conditions.

Primordial black hole growth affects their emission spectra.

Abstract

We present the particle creation probability rate around a general black hole as an outcome of quantum fluctuations. Using the uncertainty principle for these fluctuation, we derive a new ultraviolet frequency cutoff for the radiation spectrum of a dynamical black hole. Using this frequency cutoff, we define the probability creation rate function for such black holes. We consider a dynamical Vaidya model, and calculate the probability creation rate for this case when its horizon is in a slowly evolving phase. Our results show that one can expect the usual Hawking radiation emission process in the case of a dynamical black hole when it has a slowly evolving horizon. Moreover, calculating the probability rate for a dynamical black hole gives a measure of when Hawking radiation can be killed off by an incoming flux of matter or radiation. Our result strictly suggests that we have to revise the Hawking radiation expectation for primordial black holes that have grown substantially since they were created in the early universe. We also infer that this frequency cut off can be a parameter that shows the primordial black hole growth at the emission moment.