On quantum effects in the vicinity of would-be horizons

TL;DR

This paper introduces a method using Quantum Energy Inequalities to compare and bound energy densities of quantum fields near hypothetical horizons, revealing universal behaviors in certain spacetimes.

Contribution

It develops a novel approach based on Quantum Energy Inequalities to analyze quantum energy densities in spacetimes with isometric regions, especially near horizons.

Findings

Boulware energy density is universal near compact objects and horizons.

The method offers a consistency check for numerical calculations of energy-momentum tensors.

Supports the idea of universal quantum effects near would-be horizons.

Abstract

We present a method based on the so-called Quantum Energy Inequalities, which allows to compare, and bound, the expectation values of energy-densities of ground states of quantum fields in spacetimes possessing isometric regions. The method supports the conclusion, that the Boulware energy density is universal both: at modest (and far) distances from compact spherical objects, and close to the would-be horizons of the gravastar/QBHO spacetimes. It also provides a natural consistency check for concrete (approximate, numerical) calculations of the expectation values of the energy-momentum tensors.