Hawking-Like Radiation as Tunneling from a Cosmological Black Hole in Modified Gravity: Semiclassical Approximation and Beyond

TL;DR

This paper investigates Hawking-like radiation from cosmological black holes within Scalar-Tensor-Vector Gravity (STVG), analyzing semiclassical and quantum corrections, and explores how STVG parameters influence the radiation temperature and information paradox resolution.

Contribution

It introduces a novel analysis of Hawking-like radiation in STVG theory, including back-reaction effects and quantum corrections, extending understanding beyond classical semiclassical approximations.

Findings

Back-reaction effects create correlations between emission modes.

Hawking-like temperature depends on inverse powers of apparent horizon radii.

Increasing STVG parameter raises the temperature at later cosmic times.

Abstract

Hawking radiation as a quantum phenomenon is generally attributed to the existence of the event horizon of a black hole. However, we demonstrate in this paper that there is indeed ingoing Hawking-like radiation associated with apparent horizons of the first cosmological black hole solution in the framework of Scalar-Tensor-Vector Gravity (STVG) theory living in the Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) background. Such radiation can be attributed also to the cosmological apparent horizon of the FLRW universe and even to the cosmological event horizon of de Sitter spacetime. We see how STVG theory as a good theory for explaining black holes both on local and global scales affect the Hawking effect. Based on semiclassical approximation, we follow Hamilton-Jacobi and Parikh-Wilczek tunneling methods, respectively with and without back-reaction effects. We find out that back-reaction effects make a correlation between the emission modes in Parikh-Wilczek tunneling formalism, which can address the information paradox. We obtain the corresponding Hawking-like temperature as a function of inverse powers of apparent horizons radiuses of the cosmological black hole in STVG theory. We analyze the influence of the STVG parameter associated with a deviation of the STVG theory from General Theory of Relativity (GR) on both apparent horizons and the Hawking-like temperature of the cosmological black hole. We show that increasing the STVG parameter results in appearing the Hawking-like temperature in later cosmic times with some smaller values. Also, we follow the Hamilton-Jacobi approach beyond semiclassical approximation to involve all quantum correction terms in the deduced semiclassical outcomes for the cosmological black hole in the STVG theory.