PoS - Proceedings of Science
Volume 444 - 38th International Cosmic Ray Conference (ICRC2023) - Cosmic-Ray Physics (Indirect, CRI)
The impact of a modified CMB photon density on UHECR propagation
J. Meinert*, L. Morejon, A. Sandrock, B. Eichmann, J. Kreidelmeyer and K.H. Kampert
Full text: pdf
Pre-published on: July 25, 2023
Published on:
The existing discrepancies between the observation of local and extraction of global cosmological parameters motivate an extension of the $\Lambda$CDM cosmological model. A proposed extension called SU(2)$_\rm{CMB}$ describes cosmic microwave background (CMB) photons with an SU(2) instead of a U(1) gauge group. This mitigates some of these tensions, for example $H_0, \Omega_m, \sigma_8$, pushes the recombination epoch to higher redshifts, and thereby effectively reduces CMB photon densities.
In this work, we study the impact of the SU(2) modified CMB evolution on the propagation of ultra-high energy cosmic rays (UHECRs) and their related fluxes of cosmogenic photons and neutrinos. The measured and predicted fluxes are the basis used to constrain source properties and rely on the $\Lambda$CDM CMB evolution. Thus, a modification of the past CMB densities impacts these flux predictions and possibly the constraints on the sources. In particular, we show an increased proton flux below the ankle ($10^{18.5}\,$eV), and slightly increased cosmogenic neutrino fluxes in comparison to $\Lambda$CDM.
DOI: https://doi.org/10.22323/1.444.0322
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.