Tuesday, January 3, 2023

LambdaCDM Is Still Inconsistent With JWST Observations

Someday, the mountain of data, including this factor of many, is going to get the consensus of astrophysicists and cosmologists to abandon the ΛCDM Standard Model of Cosmology.
JWST high redshift galaxy observations predict a higher star formation efficiency that the standard cosmology, which poses a new tension to ΛCDM. We find that the situation is worse than expected. 
The true situation is that the Planck CMB measurement has a strong tension with JWST high redshift galaxy observations. Specifically, we make a trial to alleviate this tension by considering alternative cosmological models including dark matter-baryon interaction, f(R) gravity and dynamical dark energy. Within current cosmological constraints from Planck-2018 CMB data, we find that these models all fail to explain such a large tension. 
A possible scenario to escape from cosmological constraints is the extended Press-Schechter formalism, where we consider the local environmental effect on the early formation of massive galaxies. Interestingly, we find that an appropriate value of nonlinear environmental overdensity of a high redshift halo can well explain this tension.
Deng Wang, Yizhou Liu, "JWST high redshift galaxy observations have a strong tension with Planck CMB measurements" arXiv:2301.00347 (January 1, 2023).


neo said...

JWST high redshift galaxy observations have a strong tension with Planck CMB measurements

are Planck CMB measurements wrong ?

andrew said...


The Planck CMB measurements themselves are almost certainly not wrong.

But, they are reported in a LambdaCDM model dependent manner. They could be framed in another manner that either assumes a different model or is model independent.