English

On the effect of angular momentum on the prompt cusp formation via the gravitational collapse

Cosmology and Nongalactic Astrophysics 2023-06-12 v2 General Relativity and Quantum Cosmology

Abstract

In this work, we extend the model proposed by White concerning the post-collapse evolution of density peaks while considering the role of angular momentum. On a timescale smaller than the peak collapse, t0t_{0}, the inner regions of the peak reach the equilibrium forming a cuspy profile, as in White's paper, but the power-law density profile is flatter, namely ρr1.52\rho \propto r^{-1.52}, using the specific angular momentum JJ obtained in theoretical models of how it evolves in CDM universes, namely JM2/3J \propto M^{2/3}. The previous result shows how angular momentum influences the slope of the density profile, and how a slightly flatter profile obtained in high-resolution numerical simulations, namely ρrα\rho \propto r^{\alpha}, (α1.5)(\alpha \simeq -1.5) can be reobtained. Similarly to simulations, in our model adiabatic contraction was not taken into account. This means that more comprehensive simulations could give different values for the slope of the density profile, similar to an improvement of our model.

Cite

@article{arxiv.2305.19817,
  title  = {On the effect of angular momentum on the prompt cusp formation via the gravitational collapse},
  author = {Antonino Del Popolo and Saeed Fakhry},
  journal= {arXiv preprint arXiv:2305.19817},
  year   = {2023}
}

Comments

7 pages, 1 figure, refs. added