Non-singular non-flat universes

The quest to understand better the nature of the initial cosmological singularity is with us since the discovery of the expanding universe. Here, we propose several non-flat models, among them the standard cosmological scenario with a critical cosmological constant, the Einstein-Cartan cosmology, the Milne-McCrea universe with quantum corrections and a non flat universe with bulk viscosity. Within these models, we probe into the initial singularity by using different techniques. Several nonsingular universes emerge, one of the possibilities being a static non-expanding and stable Einstein universe. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This paper explores several non-flat universe models, including the standard cosmological scenario, Einstein-Cartan cosmology, Milne-McCrea universe with quantum corrections, and a non-flat universe with bulk viscosity. By employing various techniques, the study delves into the initial cosmological singularity, revealing the existence of nonsingular universes, such as the possibility of a static, non-expanding and stable Einstein universe.