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 CMB anomalies, consisting of a few bright
pixels, erroneously lead to regions with many low-variance circles, and
consequently sets of concentric low-variance circles, when applying the search
criteria used in previous work [V.G. Gurzadyan, R. Penrose]. After removing the
anomalies 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 degree
opening angle and after accounting for CMB anomalies. That CMB anomalies
themselves might be 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.Comment: prepared for JCAP rev