English

Baryon-to-Dark Matter Ratio from Random Angular Fields

High Energy Physics - Phenomenology 2015-06-12 v2 Cosmology and Nongalactic Astrophysics High Energy Physics - Theory

Abstract

We consider the baryon-to-dark matter ratio in models where the dark matter and baryon densities depend on angular fields \theta_{d} and \theta_{b} according to \rho_{d} ~ \theta_{d}^{\alpha} and \rho_{b} ~ \theta_{b}^{\beta}, with all values of \theta_{d} and \theta_{b} being equally probable in a given randomly-selected domain. Under the assumption that anthropic selection depends primarily on the baryon density in galaxies at spherical collapse, we show that the probability density function for the baryon-to-dark matter ratio r = \Omega_{B}/\Omega_{DM} is purely statistical in nature and is independent of anthropic selection. We compute the probability density function for r as a function of \alpha and \beta and show that the observed value of the baryon-to-dark matter ratio, r \approx 1/5, is natural in this framework.

Keywords

Cite

@article{arxiv.1211.4472,
  title  = {Baryon-to-Dark Matter Ratio from Random Angular Fields},
  author = {John McDonald},
  journal= {arXiv preprint arXiv:1211.4472},
  year   = {2015}
}

Comments

6 pages, 4 figures, version published in JCAP

R2 v1 2026-06-21T22:40:54.089Z