Late-time growth weakly affects the significance of high-redshift massive galaxies
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2025
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866915679885590528 |
|---|---|
| author | Xia, Qianran Huterer, Dragan Nguyen, Nhat-Minh |
| author_facet | Xia, Qianran Huterer, Dragan Nguyen, Nhat-Minh |
| contents | Recent observations by the James Webb Space Telescope have revealed massive galaxies at very high redshift ($z\simeq 7-15$). The question of whether the existence of such galaxies is expected in the corresponding JWST surveys has received a lot of attention, though the answer straddles areas of cosmology and complex astrophysical details of high-redshift galaxy formation. The growth rate of density fluctuations determines the amplitude of overdensities that collapse to form galaxies. Late-time modifications of growth, combined with measurements at both $z\sim 1$ from large-scale structure and $z\sim 1000$ from the cosmic microwave background, affect the predictions for the abundance of first galaxies in the universe. In this paper, we point out that the late-time growth rate of structure affects the statistical significance of high-redshift, high-mass objects very weakly. Consequently, if the existence and abundance of these objects are confirmed to be unexpected, the variations in the late-time growth history are unlikely to explain these anomalies. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_00155 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Late-time growth weakly affects the significance of high-redshift massive galaxies Xia, Qianran Huterer, Dragan Nguyen, Nhat-Minh Cosmology and Nongalactic Astrophysics Recent observations by the James Webb Space Telescope have revealed massive galaxies at very high redshift ($z\simeq 7-15$). The question of whether the existence of such galaxies is expected in the corresponding JWST surveys has received a lot of attention, though the answer straddles areas of cosmology and complex astrophysical details of high-redshift galaxy formation. The growth rate of density fluctuations determines the amplitude of overdensities that collapse to form galaxies. Late-time modifications of growth, combined with measurements at both $z\sim 1$ from large-scale structure and $z\sim 1000$ from the cosmic microwave background, affect the predictions for the abundance of first galaxies in the universe. In this paper, we point out that the late-time growth rate of structure affects the statistical significance of high-redshift, high-mass objects very weakly. Consequently, if the existence and abundance of these objects are confirmed to be unexpected, the variations in the late-time growth history are unlikely to explain these anomalies. |
| title | Late-time growth weakly affects the significance of high-redshift massive galaxies |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2503.00155 |