Growth of Structure in Multi-species Wave Dark Matter

TL;DR

This paper develops a comprehensive framework to analyze the growth of structure in multi-species wave and particle dark matter, accounting for various initial conditions and interactions.

Contribution

It derives the evolution of power spectra and cross-spectra for multiple dark matter species, including wave and particle types, with scale-dependent effects.

Findings

Framework includes cold and warm wave dark matter effects.

Derives evolution equations for power spectra and cross-spectra.

Accounts for intrinsic fluctuations and scale-dependent evolution.

Abstract

We explore the growth of structure in multi-species wave (and particle) dark matter. We derive the evolution of the power spectrum of total density contrasts for an arbitrary number of component species, density fractions, and initial field power spectra. We also derive cross-spectra for density correlations across or within individual species. Our framework includes cold and warm wave dark matter, which can give rise to significant intrinsic Poisson-like density fluctuations along with scale-dependent evolution connected to the free-streaming and Jeans scales. Such dark matter components could be globally or locally misaligned scalar fields as well as multi-component fields with spin $>0$. The framework also includes cold and warm particle dark matter in the appropriate limits.