Editing Lambda-CDM model (section)

==== High redshift galaxies ====
Observations from the [[James Webb Space Telescope]] have resulted in various galaxies confirmed by [[spectroscopy]] at high redshift, such as [[JADES-GS-z13-0]] at [[cosmological redshift]] of 13.2.<ref name="NASA-milestone">{{cite web|title = NASA's Webb Reaches New Milestone in Quest for Distant Galaxies|url = https://blogs.nasa.gov/webb/2022/12/09/nasas-webb-reaches-new-milestone-in-quest-for-distant-galaxies/|first = Thaddeus|last = Cesari|date = 9 December 2022|access-date = 9 December 2022}}</ref><ref name="Curtis-Lake2022">{{cite web|display-authors = etal|first1 = Emma|last1 = Curtis-Lake|title = Spectroscopy of four metal-poor galaxies beyond redshift ten|url = https://webbtelescope.org/files/live/sites/webb/files/home/webb-science/early-highlights/_documents/2022-061-jades/JADES_CurtisLake.pdf|date = December 2022| arxiv=2212.04568 }}</ref> Other candidate galaxies which have not been confirmed by spectroscopy include [[CEERS-93316]] at cosmological [[redshift]] of 16.4.

Existence of surprisingly massive galaxies in the early universe challenges the preferred models describing how dark matter halos drive galaxy formation. It remains to be seen whether a revision of the Lambda-CDM model with parameters given by Planck Collaboration is necessary to resolve this issue. The discrepancies could also be explained by particular properties (stellar masses or effective volume) of the candidate galaxies, yet unknown force or particle outside of the [[Standard Model]] through which dark matter interacts, more efficient baryonic matter accumulation by the dark matter halos, early dark energy models,<ref name="SmithEtAl-2022">{{cite journal|title=Hints of early dark energy in Planck, SPT, and ACT data: New physics or systematics?|author1=Smith, Tristian L.|author2=Lucca, Matteo|author3=Poulin, Vivian|author4=Abellan, Guillermo F.|author5=Balkenhol, Lennart|author6=Benabed, Karim|author7=Galli, Silvia|author8=Murgia, Riccardo|journal=Physical Review D|volume=106|issue=4|date=August 2022|page=043526 |doi=10.1103/PhysRevD.106.043526|arxiv=2202.09379|bibcode=2022PhRvD.106d3526S|s2cid=247011465 }}</ref> or the hypothesized long-sought [[Population III stars]].<ref name="Boylan-Kolchin">{{cite journal|title=Stress testing ΛCDM with high-redshift galaxy candidates|first=Michael|last=Boylan-Kolchin|journal=Nature Astronomy |year=2023 |volume=7 |issue=6 |pages=731–735 |doi=10.1038/s41550-023-01937-7 |pmid=37351007 |pmc=10281863 |arxiv=2208.01611|bibcode=2023NatAs...7..731B |s2cid=251252960 }}</ref><ref name="SciAm2022">{{cite web|title=Astronomers Grapple with JWST's Discovery of Early Galaxies|url=https://www.scientificamerican.com/article/astronomers-grapple-with-jwsts-discovery-of-early-galaxies1/|last=O'Callaghan|first=Jonathan|website=[[Scientific American]] |date=6 December 2022|access-date=10 December 2022}}</ref><ref name="BehrooziEtAl">{{cite journal|title=The Universe at z > 10: predictions for JWST from the UNIVERSEMACHINE DR1|author1= Behroozi, Peter|author2=Conroy, Charlie|author3=Wechsler, Risa H.|author4=Hearin, Andrew|author5=Williams, Christina C.|author6=Moster, Benjamin P.|author7=Yung, L. Y. Aaron|author8=Somerville, Rachel S.|author9=Gottlöber, Stefan|author10=Yepes, Gustavo|author11=Endsley, Ryan|journal=Monthly Notices of the Royal Astronomical Society|volume=499|issue=4|pages=5702–5718|date=December 2020|doi=10.1093/mnras/staa3164|doi-access= free|arxiv=2007.04988|bibcode=2020MNRAS.499.5702B}}</ref><ref name="SpringelHernquist">{{cite journal|title=The history of star formation in a Λ cold dark matter universe|author1=Volker Springel|author2=Lars Hernquist|journal=Monthly Notices of the Royal Astronomical Society|volume=339|issue=2|pages=312–334|date=February 2003|doi=10.1046/j.1365-8711.2003.06207.x|doi-access=free |arxiv=astro-ph/0206395|bibcode=2003MNRAS.339..312S |s2cid=8715136 }}</ref>