Entropy of Constrained Gravitational Instanton
Abstract
Description
The seeds for quantum creations of universes are constrained gravitational instantons. For all compact constrained instantons with U(1) isometry, the period $β$ of the group parameter $τ$ is identified as the reciprocal of the temperature. If $β$ remains a free parameter under the constraints, then the Euclidean action becomes the negative of the "entropy". As examples, we perform the calculations for the Taub-NUT and Taub-bolt-type models and study the quantum creation of the Taub-NUT universe.
8 pages
8 pages