Primordial gravitational waves in horizon cosmology and constraints on entropic parameters

TL;DR

This paper explores how a 4-parameter generalized entropy influences the evolution of the universe and the spectrum of primordial gravitational waves, proposing a way to constrain entropic parameters through future GW observations.

Contribution

It introduces a novel approach linking generalized entropy parameters with primordial GW spectra, enabling potential observational constraints.

Findings

Generalized entropy supports smooth universe evolution from inflation to radiation era.

Viable entropic parameter ranges allow primordial GWs to be detectable by future observatories.

The work suggests primordial GW detection could measure generalized entropic parameters.

Abstract

The hallmark of the 4-parameter generalized entropy is that it can represent various known entropies proposed so far for suitable limits of the parameters, and thus the 4-parameter generalized entropy can be applied on additive as well as on non-additive systems. Thereafter the proposal of the generalized entropy, it becomes important to constrain the corresponding parameters. In the present work, we intend to do this from the perspective of primordial gravitational waves (GWs) generated during inflation. In the background level, the generalized entropy successfully drives a viable and smooth evolution of the universe, particularly from inflation to reheating followed by a radiation era, for certain ranges of the entropic parameters. Consequently we investigate whether such viable ranges of the entropic parameters (coming from the background level) allow the primordial GWs spectrum to pass through the sensitivity curves of various GWs observatories. Therefore, if the future observatories can detect the signal of primordial GWs, then our theoretical expectation carried in the present work may provide a possible tool for the measurement of the generalized entropic parameters.