Despite its remarkable successes the Standard Model of Cosmology is plagued with profound theoretical and observational difficulties such as the Hubble and \(\sigma_8\) tensions. The tensions are serious enough to warrant a drastic rethinking of cosmology.

Has the JWST broken ΛCDM cosmology? A Cosmology Group seeks to understand why the Standard Model of Cosmology (ΛCDM) and alternative models have not reached the status of a stable theory, like quantum mechanics and plasma physics have in the past hundred years. The Group’s astronomers and philosophers ponder why the many hypotheses used in cosmology have remained unsatisfying and in constant need of revision. ACG does not endorse any cosmological model or statement from its members. Instead, its role is to foster a scientific discussion that will allow a systematic exploration of the universe.

As new observations reveal tensions between cosmological models, ACG scrutinizes the tenets of contemporary cosmology through a critical analysis of data that provide the observational basis for cosmology: Redshift, the Cosmic Microwave Background, Nucleosynthesis, Large-Scale Structure, and Multibillion-Year-Old Systems.

While technological progress has made possible observations of the cosmos in great detail, today’s research is mostly targeted at minor variations on the ΛCDM theme. A Cosmology Group seeks astronomical observations that are unexpected, surprising, informative, and at tension with the predictions of cosmological models. For this purpose ACG provides:

  • a database of links to observational data that challenge cosmological models,
  • discussions with established astrophysicists and philosophers,
  • examination of the methodology used for modeling and interpreting data.

After decades of development, ΛCDM cosmology is akin to an iceberg hiding 95% of its content under some unknown new physics, a situation that has been qualified as “embarrassing” by leading cosmologists. From the era of astronomers and cosmologists such as Edwin Hubble, Fritz Zwicky, Fred Hoyle and Halton Arp to the era of Alan Guth, Jim Peebles, and Adam Riess, cosmology has dramatically lost its explanatory power and increased its dependence on free parameters, unobservable objects, and untestable forces. In search of a solution, ACG encourages a dialogue with every scientist, as progress will be served best by attempting to engage as many specialists as possible. You are especially welcome to join ACG if you have published work for the development of contemporary cosmology.

A Cosmology Group maintains this website, a discussion forum, and the ACG Newsletter in a GitHub repository. Observational data and work of interest to ACG are listed in Resources. To contribute to the content of the website, please consult the project wiki.

© 2018–2024 ACG

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