Guardado en:
Detalles Bibliográficos
Autores principales: Schiff, Jonathan, Venumadhav, Tejaswi
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:https://arxiv.org/abs/2506.16517
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866908548843175936
author Schiff, Jonathan
Venumadhav, Tejaswi
author_facet Schiff, Jonathan
Venumadhav, Tejaswi
contents Recent cosmological data and astrophysical observations, such as the Hubble tension and the increasing preference from galaxy surveys for dynamical dark energy, have begun to challenge the standard $Λ$-cold dark matter cosmological model. Primordial magnetic fields (PMFs) offer a mechanism to alleviate these tensions within the framework of the standard model. These fields source excess small-scale baryon clumping, which can speed up recombination and shrink the comoving sound horizon at the surface of last scattering. Computing the modified recombination history requires coupling the radiative transport of Lyman-$α$ photons to compressible magnetohydronamic simulations. Since doing so is generically computationally intractable, we have developed a linearized treatment which self-consistently computes the modified recombination history in the presence of PMF induced baryon clumping for fields with red-tilted spectra. The clumping factors we find are too small to alleviate outstanding cosmological tensions, but our general framework can be applied to other PMF spectra, and provides a significant theoretical step towards a complete account of recombination in the presence of small-scale baryon clumping.
format Preprint
id arxiv_https___arxiv_org_abs_2506_16517
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Primordial magnetic fields and modified recombination histories
Schiff, Jonathan
Venumadhav, Tejaswi
Cosmology and Nongalactic Astrophysics
Recent cosmological data and astrophysical observations, such as the Hubble tension and the increasing preference from galaxy surveys for dynamical dark energy, have begun to challenge the standard $Λ$-cold dark matter cosmological model. Primordial magnetic fields (PMFs) offer a mechanism to alleviate these tensions within the framework of the standard model. These fields source excess small-scale baryon clumping, which can speed up recombination and shrink the comoving sound horizon at the surface of last scattering. Computing the modified recombination history requires coupling the radiative transport of Lyman-$α$ photons to compressible magnetohydronamic simulations. Since doing so is generically computationally intractable, we have developed a linearized treatment which self-consistently computes the modified recombination history in the presence of PMF induced baryon clumping for fields with red-tilted spectra. The clumping factors we find are too small to alleviate outstanding cosmological tensions, but our general framework can be applied to other PMF spectra, and provides a significant theoretical step towards a complete account of recombination in the presence of small-scale baryon clumping.
title Primordial magnetic fields and modified recombination histories
topic Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2506.16517