Abstract

Contributed Talk - Splinter LargeScale   (MW-2235)

Lyman-α Forest Signatures of Mixed Fuzzy and Cold Dark Matter

Yourong Frank Wang
Institut für Astrophysik, Georg-August-Universität Göttingen

Fuzzy dark matter (FDM) and cold dark matter (CDM) can produce near-degenerate nonlinear matter power spectra in mixed cosmologies, raising the question of whether standard structure-based probes can distinguish them. I present results from hybrid Schrödinger–Poisson and N-body simulations of a mixed FDM-CDM cosmology (axion mass m₂₂=0.01, FDM fraction f_A=0.1), comparing particle-only and full wave-mechanical evolution under matched initial conditions. Applying the Fluctuating Gunn–Peterson Approximation to generate Lyman-α flux statistics, I find that the two realizations diverge by ~10 per cent in flux power on intermediate scales, despite their near-identical matter power spectra. This divergence traces to suppressed small-scale velocity power unique to the Schrödinger–Poisson evolution — a kinematic signature invisible to N-body treatments with matched transfer functions. The result shows that Lyα flux statistics carry dynamical information beyond the matter power spectrum, opening a route to break FDM-CDM degeneracies. This work is currently under revision at MNRAS, with redshift-extended FGPA comparisons and cross-checks against established CDM pipelines underway. I will also discuss prospects for higher-order statistics, including wavelet scattering transforms, as a complementary probe of these velocity-field signatures.