1998/02/02 by Janna Levin, Evan Scannapieco, Joseph Silk · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Quantum chaos and dynamical systems #astro-ph #gr-qc
paper · pdf · doi:10.1103/physrevd.58.103516
published as Phys.Rev. D58 (1998) 103516 · 4 pages LaTeX
arxiv created 1998/02/02 · openalex publication_date 1998/10/27 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The global geometry of the Universe is in principle as observable an attribute as local curvature. Previous studies have established that if the Universe is wrapped into a flat hypertorus, the simplest compact space, then the fundamental domain must be at least 0.4 times the diameter of the observable Universe. We derive the spectrum of temperature fluctuations for the other five compact, orientable flat spaces and show that the same bound holds for all, although prominent geometric features in sky maps can, in principle, distinguish between these spaces. Our analysis provides the first limits on any of the twisted tori and the hexagonal prisms.