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Bibliographic Details
Main Authors: Tsilioukas, Stylianos A., Saridakis, Emmanuel N., Tzerefos, Charalampos
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2312.07486
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Table of Contents:
  • It is known that the appearance of microscopic objects with distinct topologies and different Euler characteristics, such as instatons and wormholes, at the spacetime-foam level in Euclidean quantum gravity approaches, leads to spacetime topology changes. Such changes, in principle, may affect the field equations that arise through the semiclassical variation procedure of gravitational actions. Although in the case of Einstein-Hilbert action the presence of microscopic wormholes does not lead to any non-trivial result, when the Gauss-Bonnet term is added in the gravitational action, the above effective topological variation procedure induces an effective cosmological constant that depends on the Gauss-Bonnet coupling and the wormhole density. Since the later in a dynamical spacetime is in general time-dependent, one obtains an effective dark energy sector of topological origin.