Cosmological solutions of emergent noncommutative gravity

TL;DR

This paper derives cosmological solutions from emergent noncommutative gravity based on matrix models, revealing a universe with a big bounce, inflation-like phase, and a Milne-like post-inflationary universe, aligning well with observations.

Contribution

It presents novel cosmological solutions within emergent noncommutative gravity from matrix models, avoiding fine-tuning and ad-hoc fields, and demonstrating compatibility with quantum mechanics.

Findings

Solutions exhibit a big bounce and inflation-like phase.

Post-inflation universe resembles Milne universe.

Results align with current cosmological observations.

Abstract

Matrix models of Yang-Mills type lead to an emergent gravity theory, which may not require fine-tuning of a cosmological constant. We find cosmological solutions of Friedmann-Robertson-Walker type. They generically have a big bounce, and an early inflation-like phase with graceful exit. The mechanism is purely geometrical, no ad-hoc scalar fields are introduced. The solutions are stabilized through vacuum fluctuations and are thus compatible with quantum mechanics. This leads to a Milne-like universe after inflation, which appears to be in remarkably good agreement with observation and may provide an alternative to standard cosmology.