Gauss-Bonnet braneworld cosmological effect on relic density of dark matter

TL;DR

This paper studies how Gauss-Bonnet braneworld cosmology alters the relic density of dark matter, showing a significant reduction in relic density when the transition temperature is low, contrasting with Randall-Sundrum results.

Contribution

It demonstrates the impact of Gauss-Bonnet modifications on dark matter relic density, highlighting differences from previous braneworld models.

Findings

Relic density decreases with lower transition temperature in Gauss-Bonnet regime.

Contrasts with Randall-Sundrum model where relic density increases.

Provides insights into dark matter behavior in modified gravity scenarios.

Abstract

In Gauss-Bonnet braneworld cosmology, the Friedmann equation of our four-dimensional universe on 3-brane is modified in a high energy regime (Gauss-Bonnet regime), while the standard expansion law is reproduced in low energies (standard regime). We investigate the Gauss-Bonnet braneworld cosmological effect on the thermal relic density of cold dark matter when the freeze-out of the dark matter occurs in the Gaugss-Bonnet regime. We find that the resultant relic density is considerably reduced when the transition temperature, which connects the Gauss-Bonnet regime with the standard regime, is low enough. This result is in sharp contrast with the result previously obtained in the Randall-Sundrum braneworld cosmology, where the relic density is enhanced.