Evidence of Vorticity and Shear at Large Angular Scales in the Wmap Data: a Violation of Cosmological Isotropy?
نویسندگان
چکیده
Motivated by the large-scale asymmetry observed in the cosmic microwave background sky, we consider a specific class of anisotropic cosmological models – Bianchi type VIIh – and compare them to the WMAP first-year data on large angular scales. Remarkably, we find evidence of a correlation which is ruled out as a chance alignment at the 3σ level. The best fit Bianchi model corresponds to x = 0.55, Ω0 = 0.5, a rotation axis in the direction (l, b) = (222 ◦,−62◦), shear (
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