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Cosmic Acceleration with and without Limits

Eric V. Linder

Submitted on 1 November 2022

Abstract

A novel, interesting class of scalar-tensor gravity theories is those with a limit on the field motion, where the scalar field either goes to a constant acceleration or stops accelerating and goes to a constant velocity. We combine these with the ability to dynamically cancel a high energy cosmological constant, e.g. through the well tempered or self tuning approaches. One can successfully have a cosmic expansion history with a matter dominated epoch and late time acceleration despite a large cosmological constant, although the late time de Sitter limit may be unstable. Pole models, such as in a Dirac-Born-Infeld action, are of particular interest for a cosmic speed limit.

Preprint

Comment: 8 pages

Subjects: General Relativity and Quantum Cosmology; Astrophysics - Cosmology and Nongalactic Astrophysics

URL: http://arxiv.org/abs/2211.00542