Open Inflation, the Four Form and the Cosmological Constant

TL;DR

This paper explores how a four-form field in quantum gravity theories can contribute to the cosmological constant, offering an anthropic solution to its small but non-zero value in open inflation models.

Contribution

It introduces the inclusion of a four-form field into open inflation models, providing a novel anthropic approach to the cosmological constant problem.

Findings

The four-form field contributes to a small cosmological constant.

The model addresses the role of singularities in open inflation.

A response to recent criticisms of the approach is provided.

Abstract

Fundamental theories of quantum gravity such as supergravity include a four form field strength which contributes to the cosmological constant. The inclusion of such a field into our theory of open inflation (hep-th/9802030) allows an anthropic solution to the cosmological constant problem in which the cosmological constant gives a small but non-negligible contribution to the density of today's universe. We include a discussion of the role of the singularity in our solution and a reply to Vilenkin's recent criticism (hep-th/9803084).