ΠΑΝΕΠΙΣΤΗΜΙΟ ΑΘΗΝΩΝ
ΤΜΗΜΑ ΦΥΣΙΚΗΣ
Πανεπιστημιούπολη Ζωγράφου

ΣΕΜΙΝΑΡΙΟ ΤΜΗΜΑΤΟΣ ΦΥΣΙΚΗΣ
Πέμπτη 20 Δεκεμβρίου 2007, 12:00
Κτίριο Φυσικής, Αίθουσα Συνελεύσεων Τμήματος

Imprints of spherical non-trivial topologies on the CMB
Dr. Αναστασία Νιάρχου
Imperial College

The apparent low power in the CMB (Cosmic Microwave Background) temperature anisotropy power spectrum derived from the WMAP satellite motivated us to consider the possibility of a non-trivial topology. We focus on some simple spherical multi-connected manifolds (Quaternionic, Octahedral, Truncated Cube and Poincare spaces) and discuss their implications for the CMB in terms of the power spectrum, maps and the correlation matrix. We also perform a Bayesian model comparison against the fiducial best-fit ΛCDM based both on the power spectrum and the correlation matrix to assess their statistical significance. We find that the 1st year power spectrum shows a slight preference for the Truncated Cube space, but the 3-year data show no evidence for any of these spaces.