I’m very happy to see my latest paper with my former MSc student Leonardo Comini and Avi Loeb out on arXiv - congratulations to Leonardo who did a significant part of the work, in what is basically the result of his MSc thesis! This work is basically an extension of Mike Boylan-Kolchin’s 2023 paper arguing that early JWST photometric data put significant pressure on the ΛCDM model. We basically asked the question of how this result changed if: 1) a proper Bayesian analysis was carried out, 2) considering also models beyond ΛCDM (e.g. models with a free equation of state or spatial curvature), and 3) using also spectroscopic data which is more reliable? The answer is that carrying out this analysis photometric data actually no longer requires an unusually high star formation efficiency, unlike (surprisingly) spectroscopic data, with the results not changing significantly in models beyond ΛCDM: the conclusion is that the origin of the “JWST tension” is likely astrophysical rather than cosmological. You can read the results in the preprint we just posted on arXiv: 2604.13866.