Asymptotic Freedom Cosmology

TL;DR

This paper explores how certain scalar-tensor gravity theories can exhibit asymptotic freedom at cosmic times approaching infinity, leading to vanishing effective gravity and potential solutions to issues in inflationary and string cosmology.

Contribution

It demonstrates a mechanism for asymptotic freedom in scalar-tensor theories, enabling cosmological models to approach de Sitter or power-law behaviors at late times.

Findings

Effective gravitational coupling approaches zero as time goes to infinity

Cosmological solutions can asymptotically resemble de Sitter or power-law expansion

Potential to address shortcomings in inflationary and string-dilaton cosmology

Abstract

For a general class of scalar--tensor gravity theories, we discuss how to recover asymptotic freedom regimes when cosmic time $t\to\pm\infty$. Such a feature means that the effective gravitational coupling $G_{eff}\to 0$, while cosmological solutions can asymptotically assume de Sitter or power--law behaviours. In our opinion, through this mechanism, it is possible to cure some shortcomings in inflationary and in string--dilaton cosmology.