Instantons from Low Energy String Actions

Abstract

We look for instanton solutions in a class of two scalar field gravity models, which includes the low energy string action in four dimensions. In models where the matter field has a potential with a false vacuum, we find that non-singular instantons exist as long as the Dilaton field found in string theory has a potential with a minimum, and provide an example of such an instanton. The class of singular instanton solutions are also examined, and we find that depending on the parameter values, the volume factor of the Euclidean region does not always vanish fast enough at the singularity to make the action finite.

revtex 6 pages with 3 figures. Minor numerical correction made

References in corpus (6)

• Open Inflation Without False Vacua
• Quantum Creation of an Open Inflationary Universe
• Quantum Creation of a Universe with $\Omega \ne 1$: Singular and Non-Singular Instantons
• Open inflation and the singular boundary
• Smooth ``creation'' of an open universe in five dimensions
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• Threebrane Absorption and Emission from a Brane-Antibrane System
• Tunnelling with Bianchi IX Instantons