2023/09/15 by Tod, Paul
#83F05 #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc)
paper · doi:10.48550/arxiv.2309.08367
When he first introduced the notion of a conformal boundary into the study of asymptotically empty space-times, Penrose noted that that the boundary would be null, space-like or time-like according as the cosmological constant Λ was zero, positive or negative. While most applications of the idea of a conformal boundary have been to the zero-Λ, asymptotically-Minkowskian case, there also has been work on the nonzero cases. Here we review work with a positive Λ, which is the appropriate case for cosmology of the universe in which we live.