An Improved Cosmological Model

TL;DR

This paper introduces a novel non-local gravitational model that explains inflation, its end, and the current acceleration of the universe through self-gravitation effects and screening mechanisms.

Contribution

It proposes a new class of non-local, action-based gravitational models that unify inflation, reheating, and late-time acceleration within a single framework.

Findings

Models describe inflation driven by a large cosmological constant.

Reheating occurs during oscillating expansion and contraction phases.

The model accounts for current cosmic acceleration via anti-screening effects.

Abstract

We study a class of non-local, action-based, and purely gravitational models. These models seek to describe a cosmology in which inflation is driven by a large, bare cosmological constant that is screened by the self-gravitation between the soft gravitons that inflation rips from the vacuum. Inflation ends with the universe poised on the verge of gravitational collapse, in an oscillating phase of expansion and contraction that should lead to rapid reheating when matter is included. After the attainment of a hot, dense universe the nonlocal screening terms become constant as the universe evolves through a conventional phase of radiation domination. The onset of matter domination triggers a much smaller anti-screening effect that could explain the current phase of acceleration.