Early Universe models from Noncommutative Geometry

TL;DR

This paper explores early universe cosmology within noncommutative geometry models, revealing emergent gravity behaviors, a running gravitational constant, and a Higgs-driven inflationary mechanism, linking particle physics to cosmological phenomena.

Contribution

It introduces a novel analysis of noncommutative geometry models applied to early universe cosmology, including emergent gravity, inflation, and dark matter insights.

Findings

Emergent Hoyle-Narlikar and conformal gravity at see-saw scales

Running effective gravitational constant affecting gravitational waves and black hole evaporation

Higgs-based slow-roll inflation with computable parameters

Abstract

We investigate cosmological predictions on the early universe based on the noncommutative geometry models of gravity coupled to matter. Using the renormalization group analysis for the Standard Model with right handed neutrinos and Majorana mass terms, which is the particle physics content of the most recent noncommutative geometry models, we analyze the behavior of the coefficients of the gravitational and cosmological terms in the Lagrangian derived from the asymptotic expansion of the spectral action functional of noncommutative geometry. We find emergent Hoyle-Narlikar and conformal gravity at the see-saw scales and a running effective gravitational constant, which affects the propagation of gravitational waves and the evaporation law of primordial black holes and provides Linde models of negative gravity in the early universe. The same renormalization group analysis also governs the running of the effective cosmological constant of the model. The model also provides a Higgs based slow-roll inflationary mechanism, for which one can explicitly compute the slow-roll parameters. The particle physics content allows for dark matter models based on sterile neutrinos with Majorana mass terms.