Casimir Densities for a Massive Fermionic Quantum Field in a Global Monopole Background with Spherical Boundary

TL;DR

This paper studies the vacuum energy-momentum tensor of a massive fermionic field in a global monopole spacetime with a spherical boundary, analyzing its behavior near the sphere and under strong gravitational fields.

Contribution

It provides a detailed analysis of vacuum densities for fermionic fields with boundary conditions in a curved spacetime with monopole topology, including asymptotic behaviors.

Findings

Vacuum densities are exponentially suppressed in strong gravitational fields.

Asymptotic behaviors are characterized near the sphere center, surface, and at large distances.

Sphere-induced expectation values depend on the solid angle deficit parameter.

Abstract

We investigate the vacuum expectation value of the energy-momentum tensor associated with a massive fermionic field obeying the MIT bag boundary condition on a spherical shell in the global monopole spacetime. The asymptotic behavior of the vacuum densities is investigated near the sphere center and surface, and at large distances from the sphere. In the limit of strong gravitational field corresponding to small values of the parameter describing the solid angle deficit in global monopole geometry, the sphere-induced expectation values are exponentially suppressed.