Cold Dark Matter from the Hidden Sector

TL;DR

This paper reviews how hidden photons and axion-like particles could be produced as cold dark matter through non-thermal mechanisms, analyzing their thermalization processes and identifying viable parameter spaces for future experiments.

Contribution

It provides a detailed analysis of the thermalization of hidden photons and identifies parameter regions where they can serve as cold dark matter candidates.

Findings

Hidden photons can survive as cold dark matter within certain parameter ranges.

The parameter space for axion-like particles as cold dark matter is constrained but promising.

Experimental searches are encouraged based on the identified viable regions.

Abstract

Weakly interacting slim particles (WISPs) such as hidden photons (HP) and axion-like particles (ALPs) have been proposed as cold dark matter candidates. They might be produced non-thermally via the misalignment mechanism, similarly to cold axions. In this talk we review the main processes of thermalisation of HP and we compute the parameter space that may survive as cold dark matter population until today. Our findings are quite encouraging for experimental searches in the laboratory in the near future.