The Angular Scale of Topologically-Induced Flat Spots in the Cosmic Microwave Background Radiation

TL;DR

This paper investigates how certain topologies of the universe can produce flat spots in the cosmic microwave background radiation, with typical flat spots around five degrees in angular scale for specific cosmological parameters.

Contribution

It demonstrates that flat spots in the CMBR are a generic feature of the cusped 3-manifold topology for certain density parameters, expanding understanding of topological signatures.

Findings

Flat spots of about five degrees are typical in the CMBR for the m003 topology.

Such flat spots are expected in other small volume cusped manifolds with similar parameters.

Topological effects can produce observable features in the CMBR sky.

Abstract

The notion that the topology of the universe need not be that of the universal covering space of its geometry has recently received renewed attention. Generic signatures of cosmological topology have been sought, both in the distribution of objects in the universe, and especially in the temperature fluctuations of the cosmic microwave background radiation (CMBR). One signature identified in the horn topology but hypothesized to be generic is featureless regions or flat spots in the CMBR sky. We show that typical observation points within the cusped 3-manifold m003 from the Snappea census have flat spots with an angular scale of about five degrees for $\Omega_0$=0.3. We expect that this holds for other small volume cusped manifolds with this $\Omega_0$ value.