Related papers: High-Redshift Galaxies from Early JWST Observation…
Early data from JWST have revealed a bevy of high-redshift galaxy candidates with unexpectedly high stellar masses. An immediate concern is the consistency of these candidates with galaxy formation in the standard cosmological model. In the…
Recent observations from the James Webb Space Telescope (JWST) have uncovered massive galaxies at high redshifts, with their abundance significantly surpassing expectations. This finding poses a substantial challenge to both galaxy…
Observations from the James Webb Space Telescope (JWST) have unveiled several galaxies with stellar masses $M_*\gtrsim10^{10} M_\odot$ at redshifts $7.4\lesssim z\lesssim 9.1$. These remarkable findings indicate an unexpectedly high stellar…
The presence of massive galaxies at high $z$ as recently observed by JWST appears to contradict the current $\Lambda$CDM cosmology. Here we aim to alleviate this tension by incorporating uncertainties from three sources in counting…
Recent JWST observations have revealed an unexpected abundance of massive galaxy candidates in the early Universe, extending further in redshift and to lower luminosity than what had previously been found by sub-millimeter surveys. These…
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 $\Lambda$CDM, or an enhanced formation…
Surveys with James Webb Space Telescope (JWST) have discovered candidate galaxies in the first 400 Myr of cosmic time. Preliminary indications have suggested these candidate galaxies may be more massive and abundant than previously thought.…
Recent observations by JWST yield a large abundance of luminous galaxies at $z\gtrsim 10$ compared to that expected in the CDM scenario based on extrapolations of the star formation efficiency measured at lower redshifts. While several…
Early observations with the James Webb Space Telescope (JWST) have revealed the existence of an unexpectedly large abundance of extremely massive galaxies at redshifts $z \gtrsim 5$: these observations are in tension with the predictions…
We compare the maximal abundance of massive systems predicted in different dynamical dark energy (DDE) models at high redshifts z = 4-7 with the measured abundance of the most massive galaxies observed to be already in place at such…
Early JWST observations reveal an unexpectedly abundant population of high-redshift candidate massive galaxies at $z \gtrsim 7$, and recent DESI measurements show a preference for dynamical dark energy, which together present a significant…
The James Webb Space Telescope (JWST) has unveiled unexpectedly massive galaxy candidates at high redshifts, challenging standard $\Lambda$CDM cosmological predictions. In this work, we study the predictions of more realistic dark matter…
Early observations with JWST indicate an over-abundance of bright galaxies at redshifts $z \gtrsim 10$ relative to Hubble-calibrated model predictions. More puzzling still is the apparent lack of evolution in the abundance of such objects…
The discovery of massive, high redshift galaxies with the James Webb Space Telescope (JWST) has been argued to challenge $\Lambda$CDM (cold dark matter): such systems would require extremely rare halos and baryon-to-stellar-mass conversion…
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…
Early JWST studies reporting an unexpected abundance of massive galaxies at $z \sim 5$--$8$ challenge galaxy formation models in the $\Lambda$CDM framework. Previous stellar mass ($M_\star$) estimates suffered from large uncertainties due…
Observations with the {\it James Webb Space Telescope} have revealed a high abundance of bright galaxies at redshift, $z\gtrsim 12$, which has been widely interpreted as conflicting with the $\Lambda$CDM model. In Cowley et al. (2018)…
This conference proceedings paper provides a short summary of the constraints presented by Menci et al. (2020) and Menci et al. (2022) to dynamical dark energy models. Dynamical dark energy (DDE) models have been proposed to address several…
Early photometric results from JWST have revealed a number of galaxy candidates above redshift 10. The initial estimates of inferred stellar masses and the associated cosmic star formation rates are above most theoretical model predictions…
Early data from the James Webb Space Telescope (JWST) has uncovered the existence of a surprisingly abundant population of very massive galaxies at extremely high redshift, which are hard to accommodate within the standard $\Lambda$CDM…