Open inflation from non-singular instantons: Wrapping the universe with a membrane

TL;DR

This paper introduces instanton solutions involving membranes that create open inflationary universes with discontinuous cosmological constants, potentially leading to eternal inflation and resolving singularities in Hawking-Turok models.

Contribution

It presents new non-singular instanton solutions with membranes that facilitate open universe creation and address singularities in prior models.

Findings

Instantons describe universe creation with membranes and discontinuous cosmological constants.

Coupling inflaton to membranes removes singularities in Hawking-Turok models.

Membrane nucleation can decrease the effective cosmological constant, enabling eternal inflation.

Abstract

The four-form field recently considered by Hawking and Turok couples naturally to a charged membrane, across which the effective cosmological constant has a discontinuity. We present instantons for the creation of an open inflationary universe surrounded by a membrane. They can also be used to describe the nucleation of a membrane on a pre-existing inflationary background. This process typically decreases the value of the effective cosmological constant and may lead to a novel scenario of eternal inflation. Moreover, by coupling the inflaton field to the membrane, the troublesome singularities which arise in the Hawking-Turok model can be eliminated.