DR. PAVAN KUMAR ALURI

A persistent signal of isotropy violation at large angular scales of the cosmic microwave background (CMB) sky is seen in erstwhile WMAP data as well as in CMB observations by recently concluded Planck mission. This has come to be called cosmic hemispherical power asymmetry (CHA), owing to the nature of the signal which has excess power in one hemisphere compared to the opposite along the axis pointing towards ~(224,-22) degrees, in galactic coordinates. In this talk, our recent study on the effect of CHA on inferred cosmological parameters in different sky directions will be presented. Later in the talk, I also discuss another related work where we probed a "cleaned" CMB sky for the presence of foreground residuals, if any. Such a study is useful to ensure that the sky left after excising galactic region and other strong sources of local microwave emission, is sufficiently clean. We found an interesting correlation between the anomalous CMB "cold spot" region and the templates of galactic synchrotron and thermal dust emission.