PREPRINT

Did JWST observe imprints of axion miniclusters or primordial black holes?

Gert Hütsi, Martti Raidal, Juan Urrutia, Ville Vaskonen, Hardi Veermäe

Submitted on 4 November 2022, last revised on 14 November 2022

Abstract

The James Webb Space Telescope has detected surprisingly luminous early galaxies that indicate a tension with the $\mathrm{\Lambda }$CDM. Motivated by scenarios including axion miniclusters or primordial black holes, we consider power-law modifications of the matter power spectrum. We show that the tension could be resolved if dark matter consists of $2×{10}^{-18}\mathrm{e}\mathrm{V}$ axions or if a fraction ${f}_{\mathrm{P}\mathrm{B}\mathrm{H}}>0.005$ of dark matter is composed of compact heavy $4×{10}^{6}{M}_{\odot }\left({f}_{\mathrm{P}\mathrm{B}\mathrm{H}}/0.005{\right)}^{-1}$ structures such as primordial black hole clusters. However, in both cases, the star formation efficiency needs to be significantly enhanced.

Preprint

Comment: 6 pages, 4 figures; references added, discussion extended

Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics; High Energy Physics - Phenomenology