Breaking de Sitter Symmetry with Cosmic Topology: Cosmological Role of Infrared Vacuum Freedom
The study investigates how nontrivial spatial topology breaks global de Sitter symmetry, removing standard arguments for ignoring zero-mode quantum vacuum contributions. By treating this freedom as a source, the paper shows that these topological effects can drive an inflationary expansion and act like a cosmological constant, suggesting the vacuum choice is crucial for semiclassical cosmology.