https://arxiv.org/abs/gr-qc/9805018 https://arxiv.org/pdf/gr-qc/9805018.pdf General Relativity and Quantum Cosmology Kaluza-Klein Gravity J. M. Overduin, P. S. Wesson (Submitted on 7 May 1998) We review higher-dimensional unified theories from the general relativity, rather than the particle physics side. Three distinct approaches to the subject are identified and contrasted: compactified, projective and noncompactified. We discuss the cosmological and astrophysical implications of extra dimensions, and conclude that none of the three approaches can be ruled out on observational grounds at the present time. Comments: 99 pages, no figures, Latex (uses elsart.sty and elsart12.sty) Also available at this http URL Subjects: General Relativity and Quantum Cosmology (gr-qc) Journal reference: Phys.Rept.283:303-380,1997 DOI: 10.1016/S0370-1573(96)00046-4 Cite as: arXiv:gr-qc/9805018 (or arXiv:gr-qc/9805018v1 for this version) Submission history From: James Overduin U. Vic [view email] [v1] Thu, 7 May 1998 05:46:35 UTC (92 KB) James M. Overduin is qualified to endorse. Kaluza-Klein Gravity James M. Overduin: Is registered as an author of this paper. Can endorse for astro-ph, astro-ph.CO, astro-ph.EP, astro-ph.GA, astro-ph.IM, gr-qc. (why?) P. S. Wesson is not registered as an owner of this paper. (why?)