Implications of the Stellar Mass Density of High-z Massive Galaxies from JWST on Warm Dark Matter

Abstract

A significant excess of the stellar mass density at high redshift has been discovered from the early data release of James Webb Space Telescope ($\it{JWST}$), and it may require a high star formation efficiency. However, this will lead to large number density of ionizing photons in the epoch of reionization (EoR), so that the reionization history will be changed, which can arise tension with the current EoR observations. Warm dark matter (WDM), via the free streaming effect, can suppress the formation of small-scale structure as well as low-mass galaxies. This provides an effective way to decrease the ionizing photons when considering a large star formation efficiency in high-$z$ massive galaxies without altering the cosmic reionization history. On the other hand, the constraints on the properties of warm dark matter can be derived from the $\it JWST$ observations. In this work, we study WDM as a possible solution to reconcile the $\it JWST$ stellar mass density of high-$z$ massive galaxies and reionization history. {\color{red}We find that, the $\it JWST$ high-$z$ comoving cumulative stellar mass density alone has no significant preference for either CDM or WDM model. But using the observational data of other stellar mass density measurements and reionization history, we obtain that the WDM particle mass with $m_{\text{W}} = 0.51^{+0.22}_{-0.12}$ eV and star formation efficiency parameter $f_{*}^0>0.39$ in 2$\sigma$ confidence level can match both the $\it JWST$ high-$z$ comoving cumulative stellar mass density and the reionization history.

Cosmological Constraints on Neutrino Masses in Light of JWST Red and Massive Candidate Galaxies

“…However, there are alternative scenarios where an enhanced SFE at high redshift does not accelerate the reionization process, and therefore it is consistent with observations. For example, Lin et al (2024) considered large SFE (0.4) at high redshift and warm dark matter in the keV mass range. In this picture, the warm dark matter has no impact on the abundance of very massive halos, and only suppresses the low-mass end of halo mass function.…”

“…This finding suggests that either the star formation efficiency (SFE) significantly exceeds its typical values in low-redshift galaxies, or the halo mass function is about 2σ higher than the prediction of the standard ΛCDM cosmology (Haslbauer et al 2022;Wang et al 2023a;Boylan-Kolchin 2023;Lovell et al 2023;Qin et al 2023). Although at the current stage a large SFE cannot be theoretically excluded (Zhang et al 2022;Qin et al 2023), a large SFE at z  7 tends to enhance the UV radiation from galaxies, causing a faster reionization process that is in tension with observation (Goto et al 2021;Wold et al 2022;Lin et al 2024). For this reason, we will take the more widely accepted conservative assumption of SFE  0.1, and discuss the cosmological implications.…”

Velocity Acoustic Oscillations on Cosmic Dawn 21 cm Power Spectrum as a Probe of Small-scale Density Fluctuations

“…To be consistent with the constraints on reionization history, massive halos may hold a larger amount of stellar mass. This can explain the high-z stellar mass excess (Gong et al 2023;Lin et al 2024). Note, however, that since the clumpiness of the IGM is also reduced in the WDM model, the reionization process is not necessarily delayed (Yue & Chen 2012).…”

Quantifying the Tension between Cosmological Models and JWST Red Candidate Massive Galaxies

“…The red candidate massive galaxies released by the James Webb Space Telescope (JWST), for instance, have inspired a debate as to whether a beyond-ΛCDM cosmology is necessary (Haslbauer et al 2022;Wang et al 2023c;Boylan-Kolchin 2023;Chen et al 2023;Ferrara et al 2023;Labbé et al 2023;Lovell et al 2023;Qin et al 2023). Plenty of beyond-ΛCDM models, including alternative dark energy (Menci et al 2022;Wang et al 2023b;Adil et al 2023), non-standard dark matter (Bird et al 2023;Dayal & Giri 2024;Lin et al 2024;Maio & Viel 2023), cosmic strings (Jiao et al 2023), primordial black holes (Gouttenoire et al 2023;Guo et al 2023;Hütsi et al 2023;Huang et al 2023;Yuan et al 2023) and many others (Lovyagin et al 2022;John & Babu Joseph 2023;Lei et al 2024;Melia 2023), have been confronted with the JWST highredshift candidate galaxies. Modification of primordial conditions may also lead to an overabundance of dark matter halos and hence more massive galaxies at high redshift (Huang 2019;Wang & Liu 2022;Forconi et al 2023;Keller et al 2023;Padmanabhan & Loeb 2023;Parashari & Laha 2023;Su et al 2023;Tkachev et al 2024).…”