Polarization of the fermionic vacuum by a global monopole with finite core

TL;DR

This paper investigates how a finite-core global monopole influences vacuum polarization effects of a massive fermionic field, analyzing energy-momentum and condensate expectations outside and inside the core, with implications for strong gravitational fields.

Contribution

It provides a detailed analysis of vacuum polarization in a spacetime with a finite-core global monopole, including explicit calculations of expectation values and asymptotic behaviors.

Findings

Core-induced vacuum densities decay at large distances

Vacuum expectation values are affected by the monopole's core structure

Inside the core, expectation values are explicitly computed for the flower-pot model

Abstract

We study the vacuum polarization effects associated with a massive fermionic field in a spacetime produced by a global monopole considering a nontrivial inner structure for it. In the general case of the spherically symmetric static core with finite support we evaluate the vacuum expectation values of the energy-momentum tensor and the fermionic condensate in the region outside the core. These quantities are presented as the sum of point-like global monopole and core-induced contributions. The asymptotic behavior of the core-induced vacuum densities are investigated at large distances from the core, near the core and for small values of the solid angle corresponding to strong gravitational fields. As an application of general results the flower-pot model for the monopole's core is considered and the expectation values inside the core are evaluated.