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Universe 2016, 2(1), 1;

The Status of Cosmic Topology after Planck Data

Laboratoire d’Astrophysique de Marseille (LAM), CNRS UMR 7326, F-13388 Marseille, France
LUTH (Observatoire de Paris), CNRS UMR 8102, F-92195 Meudon, France
Academic Editors: Stephon Alexander, Jean-Michel Alimi, Elias C. Vagenas and Lorenzo Iorio
Received: 19 November 2015 / Revised: 4 January 2016 / Accepted: 7 January 2016 / Published: 15 January 2016
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In the last decade, the study of the overall shape of the universe, called Cosmic Topology, has become testable by astronomical observations, especially the data from the Cosmic Microwave Background (hereafter CMB) obtained by WMAP and Planck telescopes. Cosmic Topology involves both global topological features and more local geometrical properties such as curvature. It deals with questions such as whether space is finite or infinite, simply-connected or multi-connected, and smaller or greater than its observable counterpart. A striking feature of some relativistic, multi-connected small universe models is to create multiples images of faraway cosmic sources. While the last CMB (Planck) data fit well the simplest model of a zero-curvature, infinite space model, they remain consistent with more complex shapes such as the spherical Poincaré Dodecahedral Space, the flat hypertorus or the hyperbolic Picard horn. We review the theoretical and observational status of the field. View Full-Text
Keywords: cosmology; general relativity; topology; cosmic microwave background; Planck telescope cosmology; general relativity; topology; cosmic microwave background; Planck telescope

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This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

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Luminet, J.-P. The Status of Cosmic Topology after Planck Data. Universe 2016, 2, 1.

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