White Noise from Dark Matter: 21 cm Observations of Early Baryon Collapse
| dc.creator | Zurek, Kathryn M. | |
| dc.creator | Hogan, Craig J. | |
| dc.date | 2007-03-26 | |
| dc.date.accessioned | 2026-07-07T11:21:23Z | |
| dc.date.available | 2026-07-07T11:21:23Z | |
| dc.description | In concordance cosmology, dark matter density perturbations generated by inflation lead to nonlinear, virialized minihalos, into which baryons collapse at redshift $z \sim 20$. We survey here novel baryon evolution produced by a modification of the power spectrum from white noise density perturbations at scales below $k \sim 10 h {Mpc}^{-1}$ (the smallest scales currently measured with the Lyman-$α$ forest). Exotic dark matter dynamics, such as would arise from scalar dark matter with a late phase transition (similar to an axion, but with lower mass), create such an amplification of small scale power. The dark matter produced in such a phase transition collapses into minihalos, with a size given by the dark matter mass within the horizon at the phase transition. If the mass of the initial minihalos is larger than $\sim 10^{-3} M_\odot$, the modified power spectrum is found to cause widespread baryon collapse earlier than standard $Λ$CDM, leading to earlier gas heating. It also results in higher spin temperature of the baryons in the 21 cm line relative to $Λ$CDM at redshifts $z > 20$ if the mass of the minihalo is larger than $1 M_\odot$. It is estimated that experiments probing 21 cm radiation at high redshift will contribute a significant constraint on dark matter models of this type for initial minihalos larger than $\sim 10 M_\odot$. Early experiments reaching to $z\approx 15$ will constrain minihalos down to $\sim 10^3 M_\odot$. | |
| dc.description | 8 pages, 9 figures | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0703624 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0703624 | |
| dc.identifier | Phys.Rev.D76:063002,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.76.063002 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/194249 | |
| dc.subject | Astrophysics | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | White Noise from Dark Matter: 21 cm Observations of Early Baryon Collapse | |
| dc.type | text |