The No-defect Conjecture: Cosmological Implications

TL;DR

This paper explores how non-trivial universe topologies impose constraints on topological defects like textures, and shows that many multi-connected universe models with such defects are incompatible with cosmic microwave background observations.

Contribution

It generalizes existing constraints on topological defects to textures and analyzes their cosmological implications in multi-connected universes.

Findings

Many multi-connected universe models with topological defects are ruled out by CMB observations.

Constraints on defect networks extend to textures in non-trivial topologies.

Certain universe topologies are incompatible with observed structure formation evidence.

Abstract

When the topology of the universe is non trivial, it has been shown that there are constraints on the network of domain walls, cosmic strings and monopoles. I generalize these results to textures and study the cosmological implications of such constraints. I conclude that a large class of multi-connected universes with topological defects accounting for structure formation are ruled out by observation of the cosmic microwave background.