Energy conditions and a bounce in FLRW cosmologies

TL;DR

This paper investigates conditions under which a cosmological bounce occurs in closed FLRW models, linking energy conditions with two types of cosmological constants, and discusses classical and quantum perspectives.

Contribution

It introduces a model-independent analysis connecting energy conditions with two cosmological constants in FLRW cosmologies, highlighting conditions for a bounce.

Findings

Identifies a range of the cosmological constant supporting energy conditions at a bounce.

Shows the applicability of energy conditions in classical and quantum cosmology.

Proposes a link between Lovelock theorem, vacuum energy, and bounce conditions.

Abstract

Exploiting the existence of two "cosmological" constants, one associated with the classical Lovelock theorem and one with the vacuum energy density, we argue, in a model independent way, that in spatially closed FLRW cosmologies with a positive definite effective cosmological constant there exists a range in this constant that serves as a sufficient condition for the satisfaction of the null, weak, strong and dominant energy conditions at a bounce. The application of energy conditions is not unambiguous and we show how the bounce can be considered classically and how, we believe more reasonably, it can be considered a matter of quantum cosmology.