Creation of a Compact Topologically Nontrivial Inflationary Universe

TL;DR

This paper explores the quantum creation probabilities of various inflationary universe topologies, highlighting conditions where nontrivial topologies are not exponentially suppressed, challenging traditional views.

Contribution

It demonstrates that under certain conditions, topologically nontrivial compact flat or open inflationary universes can be created without exponential suppression.

Findings

Quantum creation probability is suppressed for closed or infinitely large open universes.

No exponential suppression occurs for certain topologically nontrivial compact flat or open universes.

Nontrivial topologies may be more common in inflationary universe models than previously thought.

Abstract

If inflation can occur only at the energy density V much smaller than the Planck density, which is the case for many inflationary models based on string theory, then the probability of quantum creation of a closed or an infinitely large open inflationary universe is exponentially suppressed for all known choices of the wave function of the universe. Meanwhile under certain conditions there is no exponential suppression for creation of topologically nontrivial compact flat or open inflationary universes. This suggests, contrary to the standard textbook lore, that compact flat or open universes with nontrivial topology should be considered a rule rather than an exception.