# Entropy functionals and thermodynamics of relativistic geometric flows, stationary quasi-periodic Ricci solitons, and gravity

## TL;DR

This paper explores the thermodynamics of relativistic geometric flows and nonholonomic Ricci solitons, providing new methods to model gravity, dark matter, and energy structures beyond traditional entropy concepts.

## Contribution

It introduces generalized entropy functionals for relativistic Ricci flows and develops a decoupling method for complex geometric PDEs in gravity models.

## Key findings

- Explicit models of gravity and dark matter using nonholonomic configurations.
- Generalized thermodynamic variables for relativistic Ricci flows.
- Solutions with quasi-periodic and pattern forming structures in modified gravity.

## Abstract

We investigate gravity models emerging from nonholonomic (subjected to non-integrable constraints) Ricci flows. Considering generalizations of G. Perelman's entropy functionals, relativistic geometric flow equations, nonholonomic Ricci soliton, and equivalent (modified) Einstein equations are derived. There are studied nonholonomic configurations that allow explicit modeling of entropic scenarios for gravity and dark matter (in the E. Verlinde approach and/or other variants). It is shown that using the anholonomic frame deformation method, the systems of nonlinear partial differential equations for geometric flow evolution of nonlinear stationary gravitations systems can be decoupled and integrated in general forms. In this and a series of partner works, we elaborate on stationary models of emergent gravity with quasi-periodic gravitational, matter fields and dark energy/matter structure. Such configurations cannot be described thermodynamically using the concept of Bekenstein-Hawking entropy if area-entropy, holographic or duality relations are not involved. Nevertheless, generalizing G. Perelman statistic thermodynamic approach to models of relativistic Ricci flows and nonholonomic solitons, we can compute respective thermodynamic variables for all types of gravitational and matter field configurations and their geometric evolution. Nonholonomic deformations of the F- and W-entropy considered and relativistic thermodynamic models are studied in more general cases when physically important solutions with quasi-periodic and pattern forming structure are found in modified gravity theories (MGT) and general relativity (GR).