Dark Energy and Inflation with Volume Normalized Action

TL;DR

This paper explores a volume normalized action framework that removes the cosmological constant, affecting inflationary models by eliminating primordial tensor fluctuations, thus providing a new perspective on cosmic acceleration and early universe inflation.

Contribution

It introduces a volume normalized action approach that eliminates the cosmological constant and predicts the absence of primordial tensor modes in inflationary scenarios.

Findings

Inflationary background evolution remains unchanged.

Scalar perturbations are consistent with standard models.

Primordial tensor fluctuations are absent in this framework.

Abstract

In the theories described by a volume normalized action functional, an arbitrary cosmological constant is eliminated from the physical picture of our Universe, and dynamical alternatives must be responsible for today's accelerated expansion as well as for the conjectured early-time inflation in the Universe. A few well-known such scenarios realized by a single homogeneous scalar field are examined in this new context, and their diverse fates are elucidated. Typical inflationary models are not affected at the level of the background evolution, and also give rise to the scalar perturbations equivalent to those obtained in the standard General Relativity; however, the primordial quantum tensor fluctuations are absent in the new framework, irrespective of the inflationary model. As a consequence, our proposal would be ruled out should the primordial tensor modes, or their indirect consequences, be discovered in observations.