What can the detection of a single pair of circles-in-the-sky tell us about the geometry and topology of the Universe?
- Universidade Federal do Rio de Janeiro, NACO - CCS - Av. Brigadeiro Trompowski s/n 21941-590 Rio de Janeiro - RJ (Brazil)
- Centro Brasileiro de Pesquisas Fisicas, Rua Dr. Xavier Sigaud 150 22290-180 Rio de Janeiro - RJ (Brazil)
- Astronomy Unit, School of Mathematical Sciences, Queen Mary University of London Mile End Road, London, E1 4NS (United Kingdom)
In a Universe with a detectable nontrivial spatial topology, the last scattering surface contains pairs of matching circles with the same distribution of temperature fluctuations - the so-called circles-in-the-sky. Searches undertaken for nearly antipodal pairs of such circles in cosmic microwave background maps have so far been unsuccessful. Previously, we had shown that the negative outcome of such searches, if confirmed, should in principle be sufficient to exclude a detectable nontrivial spatial topology for most observers in very nearly flat (0<|{Omega}{sub tot}-1| < or approx. 10{sup -5}) (curved) universes. More recently, however, we have shown that this picture is fundamentally changed if the universe turns out to be exactly flat. In this case, there are many potential pairs of circles with large deviations from antipodicity that have not yet been probed by existing searches. Here, we study under what conditions the detection of a single pair of circles-in-the-sky can be used to uniquely specify the topology and the geometry of the spatial section of the Universe. We show that from the detection of a single pair of matching circles one can infer whether the spatial geometry is flat or not, and if so we show how to determine the topology (apart from one case) of the Universe using this information. An important additional outcome of our results is that the dimensionality of the circles-in-the-sky parameter space that needs to be spanned in searches for matching pairs of circles is reduced from six to 5 degrees of freedom, with a significant reduction in the necessary computational time.
- OSTI ID:
- 21607866
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 84, Issue 8; Other Information: DOI: 10.1103/PhysRevD.84.083507; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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