# Tunnelling black-hole radiation with $φ^3$ self-interaction: one-loop computation for Rindler Killing horizons

February 21, 2013

Tunnelling processes through black hole horizons have recently been
investigated in the framework of WKB theory discovering interesting interplay
with the Hawking radiation. A more precise and general account of that
phenomenon has been subsequently given within the framework of QFT in curved
spacetime by two of the authors of the present paper. In particular, it has
been shown that, in the limit of sharp localization on opposite sides of a
Killing horizon, the quantum correlation functions of a scalar field appear to
have thermal nature, and the tunnelling probability is proportional to
$\exp\{-\beta_{Hawking} E\}$. This local result is valid in every spacetime
including a local Killing horizon, no field equation is necessary, while a
suitable choice for the quantum state is relevant. Indeed, the two point
function has to verify a short-distance condition weaker than the Hadamard one.
In this paper we consider a massive scalar quantum field with a $\phi^3$
self-interaction and we investigate the issue whether or not the black hole
radiation can be handled at perturbative level, including the renormalisation
contributions. We prove that, for the simplest model of the Killing horizon
generated by the boost in Minkowski spacetime, and referring to Minkowski
vacuum, the tunnelling probability in the limit of sharp localization on
opposite sides of the horizon preserves the thermal form proportional to
$\exp\{-\beta_H E\}$ even taking the one-loop renormalisation corrections into
account. A similar result is expected to hold for the Unruh state in the
Kruskal manifold, since that state is Hadamard and looks like Minkowski vacuum
close to the horizon.

Keywords:

QFT on curved spacetimes, renormalization, Hawking radiation