Universal Cosmologies

TL;DR

This paper extends the analysis of universal cosmologies in 10d supergravity, exploring their dynamics and features such as late-time acceleration, scale separation, and control over corrections, with implications for string theory models.

Contribution

It advances the dynamical system analysis of universal cosmologies beyond single exponential potentials, highlighting their desirable physical properties.

Findings

Models exhibit late-time acceleration compatible with swampland bounds

Universal cosmologies can achieve scale separation and control over corrections

Open universe models possess parametric control of e-folds and decompactification avoidance

Abstract

Universal cosmologies are exact solutions of 10d type IIA supergravity containing a 4d Friedmann-Lema\^{i}tre-Robertson-Walker factor, that can also be repackaged as solutions of 4d models, i.e. as 4d consistent truncations. We extend the dynamical system analysis of universal cosmologies, beyond the case of a single exponential potential. For an open universe (negative 3d spatial curvature), these models generally possess many desirable features: parametric control of e-folds, late-time acceleration from potentials with steep exponentials (i.e. in accordance with swampland bounds), small string-loop and $\alpha'$-corrections, scale separation and/or absence of decompactification.