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arXiv · 2506.12131

Early Growth of Structure in Warm Wave Dark Matter

Mustafa A. Amin·Simon May·Mehrdad Mirbabayi
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Abstract

We explore the growth of structure in wave-like dark matter models, where the field and density spectra are peaked at sub-horizon wavenumbers. Starting with the Schr\"odinger-Poisson system, we derive the scale-dependent evolution of the matter power spectrum during radiation and matter domination. We find a suppression of adiabatic perturbations during radiation domination, controlled by a free-streaming length, and scale-dependent growth of the initially white-noise isocurvature power, controlled by a Jeans scale during matter domination. The results are in qualitative, and in some regimes quantitative, agreement with the quasi-particle picture. We verify the analytic results of the power spectrum with 3+1-dimensional cosmological Schr\"odinger-Poisson simulations. We propose an analytic formula for the halo mass function, which is in rough agreement with the simulation results at early times after matter-radiation equality. Our simulations show that early halos typically host a soliton.

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Mustafa A. Amin, Simon May, Mehrdad Mirbabayi. 2025-06-13. Early Growth of Structure in Warm Wave Dark Matter. https://doi.org/10.1088/1475-7516%2F2025%2F10%2F040

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