The discussion centers on the characteristics and models of DeSitter and AntiDeSitter universes, exploring their implications in cosmology, particularly in relation to the early universe, homogeneous and isotropic models, and the role of the cosmological constant (Lambda).
Participants appear to have differing views on the applicability and current status of various Einstein models, particularly regarding the FLRW metric and its relevance to different cosmological scenarios. The discussion remains unresolved with multiple competing views present.
Limitations include potential missing assumptions about the models discussed, dependencies on specific definitions of terms like "homogeneous," "isotropic," and "primordial density fluctuations," as well as unresolved details about the ADS/CFT correspondence.
Quantizer said:Q1
What Einstein model currently describes a Homogeneous and Isotropic approximated Universe with Matter with positive Lambda, is it still Friedmann (FLRW) or have models moved on
Which Einstein model describes an Inhomogeneous and Anisotropic very early universe with primordial density fluctuations
Thanks for that Mordred, a few pages in and already intrigued by some of the astronomical exponentials being put forwardMordred said:Its still the FLRW metric or more specifically the LCDM model, \LambdaCDM. Which also involves the Eintein field equations..
as far as the De-sitter universe usages you will probably be interested in this article.
De-Sitter musings
http://arxiv.org/abs/1205.3855
also a string theory model variant uses ADS.
ADS/CFT Anti-Desitter correspondance I'm not too familiar with how this model works yet to supply any details.