Did JWST observe imprints of axion miniclusters or primordial black holes?
Gert Hütsi, M. Raidal, Juan Urrutia, Ville Vaskonen, Hardi Veermäe
Abstract
The James Webb Space Telescope has detected surprisingly luminous early galaxies that indicate a tension with the $\mathrm{\ensuremath{\Lambda}}$ cold dark matter. 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 $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}18}\text{ }\text{ }\mathrm{eV}$ axions or if a fraction ${f}_{\mathrm{PBH}}>0.005$ of dark matter is composed of compact heavy $4\ifmmode\times\else\texttimes\fi{}{10}^{6}{M}_{\ensuremath{\bigodot}}({f}_{\mathrm{PBH}}/0.005{)}^{\ensuremath{-}1}$ structures such as primordial black hole clusters. However, in both cases, the star formation efficiency needs to be significantly enhanced.