Interference with Gravitational Instability: Hot and Fuzzy Dark Matter

Abstract

Wave or fuzzy dark matter produced with high momenta behaves in many ways like hot particle dark matter while also possessing seemingly different phenomenology due to wave interference. We develop wave perturbation theory to show that white noise density fluctuations generated by the interference of high-momenta waves are gravitationally unstable in the usual way during matter domination above the free streaming scale and stabilize below the free streaming scale, much like the analogous effects for massive neutrinos in hot dark matter. We verify and illustrate these effects in the density power spectra of Newtonian Schrödinger-Poisson simulations. In the cosmological context, this would cause a gradual suppression of the initial white noise isocurvature perturbations below the free streaming scale at matter radiation equality, unlike cold dark matter isocurvature fluctuations, and virial stability of dark matter halos.

8 pages, 4 figures. Version accepted in PRD

References in corpus (7)

• Cold and Fuzzy Dark Matter
• Wave Dark Matter
• Early seeds of axion miniclusters
• PyUltraLight: A Pseudo-Spectral Solver for Ultralight Dark Matter Dynamics
• Early Structure Formation Constraints on the Ultra-Light Axion in the Post-Inflation Scenario
• Simulations of axion-like particles in the post-inflationary scenario
• Warm and Fuzzy Dark Matter: Free Streaming of Wave Dark Matter

Cited by in corpus (2)

• Early Growth of Structure in Warm Wave Dark Matter
• Warm, not Fuzzy: Generalized Ultralight Dark Matter Limits from Milky Way Satellites