Saving the universe with finite volume effects

Abstract

Setting aside anthropic arguments, there is no reason why the universe should initially favour a net expanding phase rather than one experiencing a net contraction. However, a collapsing universe containing "normal" matter will end at a singularity in a finite time. We point out that there is a mechanism, derived from non-perturbative effects in Quantum Field Theory in a finite volume, which may provide a bias towards expansion when the spacetime volume shrinks, by dynamically violating the null energy condition, without the need for modified gravity or exotic matter. We describe a scalar field component subjected to this non-perturbative effect in a cosmological background and consider its impact on a contracting phase. We discuss how this could dynamically generate the necessary initial conditions for inflation to get started, or form part of the mechanism for a non-singular cosmological bounce.

8 pages, 2 figures, comments and references added

References in corpus (4)

• Non-perturbative Gravity, Hagedorn Bounce & CMB
• Bouncing Cosmology made simple
• Robustness of Inflation to Large Tensor Perturbations
• Quantum Incompleteness of Inflation

Cited by in corpus (4)

• Tunnelling and dynamical violation of the Null Energy Condition
• Cosmic bounce and phantom-like equation of state from tunnelling
• Null energy condition violation: Tunnelling versus the Casimir effect
• One-loop tunnelling-induced energetics