Structure formation with primordial black holes to alleviate early star formation tension revealed by JWST

Abstract

Context. This Letter explores the potential role of primordial black holes (PBHs) to address cosmological tensions as the presence ofmore massive than expected galaxies at high redshifts, as indicated by recent James Webb Space Telescope observations.Aims. Motivated by inflation models that enhance the power at scales beyond the observable range that produce PBHs with Schechter-like mass functions, we aim to explain the excess of high redshift galaxies via a modification of the Λ cold dark matter power spectrumthat consists in adding (i) a blue spectral index nb at kpiv = 10/Mpc and (ii) Poisson and isocurvature contributions from massive PBHsthat only make up 0.5% of the dark matter.Methods. We simulated these models using the SWIFT code and find an increased abundance of high redshift galaxies in simulationsthat include PBHs. We compared these models to estimates from James Webb Space Telescope observations.Results. Unlike the Λ cold dark matter model, the inclusion of PBHs allowed us to reproduce the observations with reasonable valuesfor the star formation efficiency. Furthermore, the power spectra we adopted potentially produce PBHs that can serve as seeds forsupermassive black holes with masses 7.57 × 104 M.