High-redshift galaxies from JWST observations in more realistic dark matter halo models

The James Webb Space Telescope (JWST) has unveiled unexpectedly massive galaxy candidates at high redshifts, challenging standard Lambda cold dark matter () cosmological predictions. In this work, we study the predictions of more realistic dark matter halo models combined with modified matter power spectra for interpreting JWST observations of high-redshift galaxies. We employ three halo mass functions: the conventional Sheth-Tormen (ST) model and two physically motivated alternatives introduced by Del Popolo (DP1 and DP2) that incorporate angular momentum, dynamical friction, and cosmological constant effects. These are coupled with parametrically modified power spectra featuring small-scale enhancements characterized by spectral indices and characteristic scales, motivated by cosmological scenarios. Our analysis of cumulative stellar mass densities at z8--10 reveals that the standard ST mass function systematically underpredicts JWST observations, achieving marginal consistency only with high star formation efficiencies. The DP1 and DP2 models show improved agreement within standard, with DP2 consistent with JWST measurements at the 1 level for moderate star formation efficiencies. While modified power spectra can further alleviate residual tensions, the statistical support for these extended models requires further investigation. In cases where DP2 predictions deviate from JWST observations by more than 2, which often occurs at excessively high star formation efficiencies, the applied corrections fail to completely eliminate the tension. Our results demonstrate that incorporating realistic halo collapse physics, often neglected in standard analyses, can substantially alleviate apparent tensions between JWST observations and predictions, highlighting the critical importance of small-scale structure formation physics in early cosmic epochs.