# Ground state energy and topological mass in spacetimes with nontrivial topology

## TL;DR

This paper studies the ground state energy and topological mass generation of a massless scalar field in spacetimes with nontrivial topology, using one and two-loop corrections in quasi-periodic and boundary-identified universes.

## Contribution

It introduces a detailed analysis of quantum effects on scalar fields in nontrivial topologies, including new calculations of effective potential corrections.

## Key findings

- Ground state energy depends on spacetime topology.
- Topological mass can be generated through quantum corrections.
- Results extend previous literature on quantum fields in curved spacetime.

## Abstract

In the present paper, we investigate the ground state energy of a massless scalar field and generation of topological mass by considering a quasi-periodically identified Minkowski spacetime and the `half-Einstein Universe', that is, an Einstein Universe where the massless scalar field propagates under Dirichlet boundary condition. The analysis is performed considering one and two-loop corrections to the effective potential in both cases. Our results are compared with previous results found in literature.