Gespeichert in:
| Hauptverfasser: | , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2026
|
| Schlagworte: | |
| Online-Zugang: | https://arxiv.org/abs/2604.13866 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866913092990926848 |
|---|---|
| author | Comini, Leonardo Vagnozzi, Sunny Loeb, Abraham |
| author_facet | Comini, Leonardo Vagnozzi, Sunny Loeb, Abraham |
| contents | Early observations from the James Webb Space Telescope (JWST) have revealed an overabundance of massive high-redshift galaxies, raising the question of whether this points to new physics beyond $Λ$CDM, or an enhanced formation efficiency of massive stars. We revisit this issue going beyond earlier analyses based on direct comparisons to theoretical bounds at a fixed cosmology, by performing a full Bayesian analysis of the most extreme galaxies in the CEERS imaging and FRESCO spectroscopic samples, jointly constraining cosmological parameters and the baryon-to-star conversion efficiency $ε$. We do so not only within the spatially flat $Λ$CDM model, but also in models where the dark energy equation of state $w$ and/or the spatial curvature parameter $Ω_K$ are allowed to vary, carefully discussing the impact of both $w$ and $Ω_K$ on the cumulative comoving stellar mass density. Within the flat $Λ$CDM model, once cosmological parameters are marginalized over, the CEERS sample provides a weak $2σ$ lower limit of $ε\gtrsim 0.07$, compatible with astrophysical expectations. In contrast, the FRESCO sample requires $ε\gtrsim 0.5$ at $2σ$, with values $ε\lesssim 0.2$ disfavored at $>5σ$. These results do not qualitatively change when we allow $w$ and/or $Ω_K$ to vary, with no evidence for deviations from $w=-1$ or $Ω_K=0$. Our results therefore suggest that the origin of the ``JWST tension'' is unlikely to be cosmological, but lies in the astrophysics of galaxy formation. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2604_13866 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Dark energy, spatial curvature, and star formation efficiency from JWST photometric and spectroscopic high-redshift galaxies Comini, Leonardo Vagnozzi, Sunny Loeb, Abraham Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies General Relativity and Quantum Cosmology High Energy Physics - Phenomenology Early observations from the James Webb Space Telescope (JWST) have revealed an overabundance of massive high-redshift galaxies, raising the question of whether this points to new physics beyond $Λ$CDM, or an enhanced formation efficiency of massive stars. We revisit this issue going beyond earlier analyses based on direct comparisons to theoretical bounds at a fixed cosmology, by performing a full Bayesian analysis of the most extreme galaxies in the CEERS imaging and FRESCO spectroscopic samples, jointly constraining cosmological parameters and the baryon-to-star conversion efficiency $ε$. We do so not only within the spatially flat $Λ$CDM model, but also in models where the dark energy equation of state $w$ and/or the spatial curvature parameter $Ω_K$ are allowed to vary, carefully discussing the impact of both $w$ and $Ω_K$ on the cumulative comoving stellar mass density. Within the flat $Λ$CDM model, once cosmological parameters are marginalized over, the CEERS sample provides a weak $2σ$ lower limit of $ε\gtrsim 0.07$, compatible with astrophysical expectations. In contrast, the FRESCO sample requires $ε\gtrsim 0.5$ at $2σ$, with values $ε\lesssim 0.2$ disfavored at $>5σ$. These results do not qualitatively change when we allow $w$ and/or $Ω_K$ to vary, with no evidence for deviations from $w=-1$ or $Ω_K=0$. Our results therefore suggest that the origin of the ``JWST tension'' is unlikely to be cosmological, but lies in the astrophysics of galaxy formation. |
| title | Dark energy, spatial curvature, and star formation efficiency from JWST photometric and spectroscopic high-redshift galaxies |
| topic | Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies General Relativity and Quantum Cosmology High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2604.13866 |