Possibilities and surprises of vacuum dark fluid

Abstract

We address the question of a unified description of dark energy and dark matter based on the spacetime symmetry which makes it possible to approach these two problems on a common ground. In this approach, a cosmological vacuum is described by a variable cosmological term whose symmetry is reduced as compared with the Einstein cosmological term, which allows the vacuum energy to be evolving and clustering. The relevant class of solutions to the Einstein equations implies the existence of compact vacuum objects generically related to dark energy: regular black holes, their remnants and self-gravitating vacuum solitons with de Sitter vacuum interior—which can be responsible for the observational effects typically related to dark matter. The mass of an objects with de Sitter interior is generically related to the vacuum dark energy and to spacetime symmetry breaking.