{"arxiv_id":"2611.15188","title":"Non-Gaussian matter fluctuations from primordial magnetic fields and galaxy luminosity function","abstract":"Primordial magnetic fields (PMFs) represent a promising candidate for the origin of large-scale magnetic fields observed in astrophysical environments. Through the Lorentz force, PMFs generate matter density perturbations, leaving distinct imprints on the formation of cosmic structures. While previous studies have primarily characterized these imprints via the matter power spectrum --- a two-point statistic --- we demonstrate that the one-point statistics of PMF-induced density fluctuations reveal an intrinsically non-Gaussian probability distribution function (PDF), even when the PMFs themselves are statistically Gaussian. In particular, we find that the high-density tail of the PDF is enhanced by over two orders of magnitude relative to the Gaussian case. Adopting the Press-Schechter formalism, we show that this non-Gaussianity significantly boosts the abundance of rare objects, especially massive halos and those at high redshifts. We further compute the ultraviolet luminosity function of galaxies at $z=6$, $12$, and $16$, and compare our predictions with recent James Webb Space Telescope (JWST) observations that have reported an excess of high-redshift galaxies at $z\\sim 12$ -- $16$ relative to standard $\\Lambda$CDM expectations. Intriguingly, in the limiting case where the total density field inherits this PDF, our results suggest that the non-Gaussian density fluctuations sourced by PMFs can explain the bright-end ($M_\\mathrm{UV}\\lesssim -18$) excess at $z\\gtrsim 12$, without requiring additional astrophysical enhancements to star-formation efficiency.","primary_cat":"astro-ph.CO","cross_cats":["astro-ph.GA","astro-ph.HE","gr-qc"],"submitted_at":"2026-11-11T08:35:51+00:00","latest_version":1,"source":"arxiv","source_label":"arXiv","source_url":null,"has_pdf":true,"has_source":false,"verdict":"CONDITIONAL","confidence":"HIGH","one_line_summary":"Primordial magnetic fields generate non-Gaussian density fluctuations whose exponential tail can explain the JWST excess of bright galaxies at z~12-16 within the Press-Schechter framework.","novelty_score":6.0,"correctness_risk":"high","formal_verification":"none","upvotes":0,"downvotes":0,"pith_score":0,"inbound_count":0,"_links":{"html":"https://pith.science/paper/2611.15188","verdict":"/api/v1/verdicts/2611.15188"}}