Stability of Flat Space to Singular Instantons

Abstract

Hawking and the author have proposed a class of singular, finite action instantons for defining the initial conditions for inflation. Vilenkin has argued they are unacceptable. He exhibited an analogous class of asymptotically flat instantons which on the face of it lead to an instability of Minkowski space. However, all these instantons must be defined by introducing a constraint into the path integral, which is then integrated over. I show that with a careful definition these instantons do not possess a negative mode. Infinite flat space is therefore stable against decay via singular instantons.

9 pages, RevTex file, including two postscript figure files. Minor typos corrected, figure improved

References in corpus (3)

• Open Inflation Without False Vacua
• Open Inflation, the Four Form and the Cosmological Constant
• Cosmological Perturbations from the No Boundary Euclidean Path Integral

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