Dark Matter Production from Primordial Black Hole Evaporation: Gravitational Freeze-In with Multimodal Mass and Extended Spin Distributions

Primordial black holes (PBHs) formed through different mechanisms follow extended, rather than monochromatic, mass and spin distributions. Building on the public FRISBHEE code, implementing four PBH mass functions (log-normal, power-law, critical collapse, metric preheating), we introduce a multimodal framework modeling the global population as a superposition of these components, and compare alternative weighting schemes. Spin follows a Gaussian profile or the universal post-merger distribution of Fishbach et al. For [Formula: see text], we compute the gravitationally produced dark matter relic abundance across all distributions and spin configurations. Extended distributions suppress the relic abundance relative to the monochromatic benchmark according to the mass-function breadth, with the hierarchy reorganizing at non-zero spin. The weighting scheme is the dominant source of theoretical uncertainty, shifting predictions by up to [Formula: see text]38%; extended distributions relax the [Formula: see text] bound by up to [Formula: see text]2.4 and shift the Planck-compatible mass windows by 15–25%, showing that the PBH formation channel is itself an observable.