Universal spectrum and scaling laws for halo mass function, structure, and dark matter mass constraints
Abstract
Between the linear and nonlinear regimes, we identify a universal transition range centered on a characteristic halo mass , within which gravitational dynamics self-organize the matter field toward an effective spectral index n=-1. In a bottom-up hierarchy, early collapse of low-mass halos preserves imprints of the primordial spectrum, whereas prolonged assembly of halos near erases that memory and establishes universality. We formulate a scale-to-scale cascade, the redistribution of mass and energy across scales, that yields universal scaling laws for the halo mass function and internal structure. Globally, the cascade drives a random walk of halos with mass-dependent waiting time ; A Fokker-Planck equation gives mass function and for the gravity-dominant transition range. Locally, a radially directed cascade governs particle migration with waiting time , yielding density and on scales near . The cascade drives the system toward a statistically steady state that continuously releases energy and maximizes entropy, characterized by scale-independent rates, preventing mass or energy buildup at intermediate scales. Scale-dependent dominance of the primordial spectrum versus gravity implies two effective exponents, producing double- mass functions and double- density in excellent agreement with simulations. Using Illustris and Virgo, we measure an inverse kinetic-energy cascade from small to large scales at m/s, a direct potential-energy cascade of , and a net dissipation of -0.4 via halo mergers and particle migration. The dependence of waiting time and step length on the particle mass suggests new constraints near GeV.
Keywords
Cite
@article{arxiv.2109.09985,
title = {Universal spectrum and scaling laws for halo mass function, structure, and dark matter mass constraints},
author = {Zhijie Xu},
journal= {arXiv preprint arXiv:2109.09985},
year = {2025}
}
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