Spectral Variations of the Sky: Constraints on Alternate Universes

TL;DR

This paper investigates spectral anomalies in Planck CMB data, suggesting possible signatures of universe collisions with alternate universes, and proposes that enhanced hydrogen emission could explain observed residuals.

Contribution

It introduces a novel analysis of spectral anomalies in CMB data that may indicate universe collisions, proposing a specific physical mechanism involving altered baryon-to-photon ratios.

Findings

Detection of anomalously strong 143 GHz emission in four regions

Residual emission significance exceeds 6σ before foreground subtraction

Less than 0.5 ext{%} probability that foregrounds explain all excess

Abstract

The fine tuning of parameters required to reproduce our present day Universe suggests that our Universe may simply be a region within an eternally inflating super-region. Many other regions beyond our observable Universe would exist with each such region governed by a different set of physical parameters. Collision between these regions, if they occur, should leave signatures of anisotropy in the cosmic microwave background (CMB) but have not been seen. We analyze the spectral properties of masked, foreground-cleaned maps between 100 and 545 GHz constructed from the Planck dataset. Four distinct $\sim2-4\arcdeg$ regions associated with CMB cold spots show anomalously strong 143 GHz emission but no correspondingly strong emission at either 100 or 217 GHz. The signal to noise of this 143 GHz residual emission is at the $\gtrsim$6$\sigma$ level which reduces to $3.2-5.4\sigma$ after subtraction of remaining synchrotron/free-free foregrounds. We assess different mechanisms for this residual emission and conclude that although there is a 30\% probability that noise fluctuations may cause foregrounds to fall within 3$\sigma$ of the excess, there is less than a 0.5\% probability that foregrounds can explain all the excess. A plausible explanation is that the collision of our Universe with an alternate Universe whose baryon to photon ratio is a factor of $\sim$4500 larger than ours, could produce enhanced Hydrogen Paschen-series emission at the epoch of recombination. Future spectral mapping and deeper observations at 100 and 217 GHz are needed to mitigate systematics arising from unknown Galactic foregrounds and to confirm this unusual hypothesis.