Tsallis cosmology and its applications in dark matter physics with focus on IceCube high-energy neutrino data

TL;DR

This paper develops a Tsallis-based thermodynamic framework for cosmology, applying it to dark matter and high-energy neutrino data, and finds that a specific Tsallis scaling exponent resolves discrepancies in dark matter relic abundance and IceCube observations.

Contribution

It introduces a novel thermodynamic formulation using Tsallis entropy into cosmology and demonstrates its effectiveness in addressing dark matter and neutrino data discrepancies.

Findings

Tsallis cosmology modifies Friedmann equations with a specific scaling exponent.

A Tsallis exponent of approximately 1.57 resolves dark matter and neutrino data conflicts.

The approach offers a new thermodynamic perspective on cosmological models.

Abstract

In this paper we employ a recent proposal of C. Tsallis and formulate the first law of thermodynamics for gravitating systems in terms of the extensive but non-additive entropy. We pay a particular attention to an integrating factor for the heat one-form and show that in contrast to conventional thermodynamics it factorizes into thermal and entropic part. Ensuing first law of thermodynamics implies Tsallis cosmology, which is then subsequently used to address the observed discrepancy between current bound on the Dark Matter relic abundance and present IceCube data on high-energy neutrinos. To resolve this contradiction we keep the conventional minimal Yukawa-type interaction between standard model and Dark Matter particles but replace the usual Friedmann field equations with Tsallis-cosmology-based modified Friedmann equations. We show that when the Tsallis scaling exponent $\delta \sim 1.57$ (or equivalently, the holographic scaling exponent $\alpha \sim 3.13$) the aforementioned discrepancy disappears.