Scalar field theory for warm dark matter

TL;DR

This paper develops scalar field models, both minimally and non-minimally coupled to gravity, that replicate the cosmological behavior of warm dark matter described by the reduced relativistic gas model, including conformal symmetry and potential integration with dynamical dark energy.

Contribution

It constructs novel scalar field actions equivalent to the RRG model of warm dark matter, including models with conformal symmetry and potential for dynamical dark energy integration.

Findings

Scalar field actions matching RRG cosmological solutions.

Models with conformal symmetry for ultra-relativistic particles.

Potential extension with running cosmological constant.

Abstract

The warm dark matter (WDM) can be described by simple and useful model called reduced relativistic gas (RRG). In this work, it is analytically constructed the scalar field actions minimally and non-minimally coupled to gravity, which are equivalent to RRG in the sense they produce the same cosmological solutions for the conformal factor of the metric. In particular, we construct the scalar theory which corresponds to the model of ultra-relativistic ideal gas of spinless particles possessing conformal symmetry. Finally, the possibility of supplementing our scalar field model with a dynamical dark energy in the form of a running cosmological constant (RCC) is also considered.