Vacuum Polarization by a Scalar Field in de Sitter Spacetime in the Presence of a Global Monopole

摘要

We analyze vacuum polarization effects associated with massive scalar quantum fields in a higher-dimensional de Sitter space in the presence of a global monopole. Because this analysis has been developed in pure de Sitter space, we are mainly interested on the effects induced by the presence of the global monopole. So, to achieve this objective, we calculate the corresponding Wightman function, which is expressed in an integral representation and explicitly depends on the parameters associated with the presence of the monopole and-the cosmological constant. Admitting that the former is closed to unity, which corresponds to a realistic value predicted by Grand Unified Theories, it is possible to express this function as a sum of two terms: the first one corresponds to the Wightman function on the bulk where the global monopole is absent, and the second one is a contribution induced by the presence of the monopole.