Growth of Cosmic Structures in generalized mass-to-horizon relation Entropic Cosmology

TL;DR

This paper explores cosmic structure growth within a generalized entropic cosmology framework, showing it aligns with LCDM predictions and offers a thermodynamically consistent explanation for the Universe's accelerated expansion.

Contribution

It introduces a thermodynamically consistent generalized entropic cosmology model that matches LCDM growth and background evolution without additional free parameters.

Findings

Fully perturbed growth matches LCDM within uncertainties

Model satisfies Clausius relation and avoids earlier inconsistencies

Provides a viable entropic explanation for cosmic acceleration

Abstract

We investigate the growth of cosmic structures in the thermodynamically consistent generalised mass-to-horizon entropic cosmology (MHEC). For the Bekenstein case the entropic energy density augments the Friedmann equations without modifying the Hawking temperature and automatically satisfies the Clausius relation, thereby avoiding the inconsistencies that afflicted earlier entropy-force models. We then derive the linear perturbation equations, emphasising the distinction between a fully perturbed interaction term and the common approximation in which the perturbation is neglected. Numerical solutions show that fully perturbed follows the LCDM matter-growth history within the current growth uncertainties. Our results demonstrate that MHEC matches both background and growth probes as well as LCDM without extra free parameters, providing a viable entropic explanation for recent accelerated expansion of the Universe.