The quest for CMB signatures of conformal cyclic cosmology

Circles of low-variance and Hawking points in the Cosmic Microwave Background (CMB), resulting from black hole mergers and black hole evaporation, respectively, in a previous cycle of the universe, have been predicted as possible evidence for the Conformal Cyclic Cosmology model (CCC) introduced by...

Full description

Saved in:
Bibliographic Details
Published in:Journal of cosmology and astroparticle physics 2024-05, Vol.2024 (5), p.9
Main Authors: Bodnia, Eve, Isenbaev, Vlad, Colburn, Kellan, Swearngin, Joe, Bouwmeester, Dirk
Format: Article
Language:English
Subjects:
Algorithms
Black holes
Cosmic microwave background
cosmic singularity
Cosmology
Evaporation
High temperature
Low temperature
Machine learning
non-gaussianity
Open source software
power spectrum
Searching
Signatures
Variance
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Circles of low-variance and Hawking points in the Cosmic Microwave Background (CMB), resulting from black hole mergers and black hole evaporation, respectively, in a previous cycle of the universe, have been predicted as possible evidence for the Conformal Cyclic Cosmology model (CCC) introduced by R. Penrose. We present a high-resolution search for such low-variance circles in the Planck and WMAP CMB data, and introduce HawkingNet, our machine learning open-source software based on a ResNet18 algorithm, to search for Hawking points in the CMB. We find that spots consisting of a few unusually bright (high-temperature) or dark (low-temperature) pixels, erroneously lead to regions with many low-variance circles, and consequently sets of near-concentric low-variance circles, when applying the search criteria used in previous work [1]. After removing those spots from the data, no statistically significant low-variance circles can be found. Concerning Hawking points, also no statistically significant evidence is found when using a Gaussian temperature amplitude model over ∼ 1° opening angle and after accounting for spots of unusual brightness. That the unusual spots in the data are themselves remnants of Hawking points is not supported by low-variance and/or low-temperature circles around them. The absence of such statistically-significant distinct features in the currently available CMB data does not disprove the CCC model, but implies that higher resolution CMB data and/or refined CCC based predictions are needed to pursue the search for CCC signatures further.
ISSN:1475-7516
1475-7516
DOI:10.1088/1475-7516/2024/05/009