# Thermodynamic approach to holographic dark energy and the R\'{e}nyi entropy

## TL;DR

This paper develops a new holographic dark energy model based on a thermodynamic relation involving Rényi entropy, successfully explaining the universe's accelerated expansion without requiring interaction between cosmic sectors.

## Contribution

It introduces a novel dark energy model derived from thermodynamics and Rényi entropy, linking entropy, IR, and UV cutoffs in a cosmological context.

## Key findings

- The model explains the universe's accelerated expansion.
- It demonstrates the suitability of generalized entropy for gravitational systems.
- The approach provides a theoretical framework for dark energy without sector interaction.

## Abstract

Using the first law of thermodynamics, we propose a relation between the system entropy ($S$) and its IR ($L$) and UV ($\Lambda$) cutoffs. In addition, applying this relation to the apparent horizon of flat FRW universe, whose entropy meets the R\'{e}nyi entropy, a new holographic dark energy model is addressed. Thereinafter, the evolution of the flat FRW universe, filled by a pressureless source and the obtained dark energy candidate, is studied. In our model, there is no mutual interaction between the cosmos sectors. We find out that the obtained model is theoretically powerful to explain the current accelerated phase of the universe. This result emphasizes that the generalized entropy formalism is suitable for describing systems including the long-range interactions such as gravity.