The interacting multiverse and its effect on the cosmic microwave background

TL;DR

This paper introduces a quantum multiverse model where universe interactions induce a pre-inflationary phase, affecting cosmic microwave background predictions and potentially explaining observed large-scale anomalies.

Contribution

It presents a novel quantum multiverse framework with interacting universes that influence early universe dynamics and CMB anisotropies.

Findings

Pre-inflationary phase causes large-scale power suppression.

Model aligns with Planck 2018 CMB data.

Potential explanation for quadrupole anomaly.

Abstract

We study a toy model of a multiverse consisting of canonically quantized universes that interact with each other on a quantum level based on a field-theoretical formulation of the Wheeler-DeWitt equation. This interaction leads to the appearance of a pre-inflationary phase in the evolution of the individual universes. We analyze scalar perturbations within the model and calculate the influence of the pre-inflationary phase onto the power spectrum of these perturbations. The result is that there is a suppression of power on large scales, which can describe well the Planck 2018 data for the cosmic microwave background anisotropies and could thus indicate a possible solution to the observed quadrupole discrepancy.