Nonsingular bouncing cosmology in general relativity: physical analysis of the spacetime defect

TL;DR

This paper analyzes a nonsingular bouncing cosmology within general relativity, focusing on physical effects near a spacetime defect, revealing intense forces and unusual energy behaviors that distinguish it from standard cosmological models.

Contribution

It provides a physical analysis of spacetime defects in regularized Robertson-Walker spacetime, highlighting effects like intense forces and energy anomalies during the bounce.

Findings

Compressive forces near the defect become extremely intense, preventing crossing.

Energy behavior around the bounce is markedly different from standard cosmology.

Physical effects can reveal the presence of the spacetime defect.

Abstract

In this paper, we describe physical effects occurring in the regularized Robertson-Walker spacetime which can reveal the presence of the defect. Our analysis is based on two main physical quantities: the compressive forces acting on (human) observers and the energy possessed by massive particles and photons during their dynamical evolution. In Sec. 3, we claim that with a characteristic length scale of the order of the Planck length compressive forces become so intense near the defect that no (human) observer is able to cross it. In Sec. 4, we show that the energy exhibits an unusual character over a small time interval around the bounce contrasting with the behaviour in the standard cosmology picture. We conclude the paper with some considerations and open problems related to our results.