Averaged Energy Conditions and Bouncing Universes

TL;DR

This paper explores how bouncing universes can violate traditional energy conditions locally but still satisfy averaged energy conditions, providing explicit examples across various models.

Contribution

It introduces the concept of averaged energy conditions in bouncing universes and demonstrates their validity through explicit examples in different frameworks.

Findings

Null energy condition can be locally violated during bounce

Averaged energy conditions can hold despite local violations

Explicit models show the feasibility of averaged conditions in bouncing scenarios

Abstract

The dynamics of bouncing universes is characterized by violating certain coordinate invariant restrictions on the total energy-momentum tensor, customarily referred to as energy conditions. Although there could be epochs where the null energy condition is locally violated, it may perhaps be enforced in an averaged sense. Explicit examples of this possibility are investigated in different frameworks.