Colloquium:: Structured test of the Cosmological principle

with Tarun Souradeep, Raman Research Institute

The Cosmological Principle, a fundamental tenet of the 'standard model of cosmology',  predicates a statistically isotropic distribution of fluctuations in the measured Cosmic Microwave Background (CMB)  temperature and polarisation sky maps. Enigmatic anomalies  claimed in the WMAP and Planck  CMB sky maps could challenge the standard model. However, these claims need to be cast in an objective  mathematical  framework  and established with statistical rigour. Bayesian inference of the underlying covariance  structure of random fields on the sphere in the Bipolar Spherical Harmonic  (BipoSH) representation developed in our research program provides such a framework.  We review the recent inferences drawn from Planck data and dwell on the future  prospects with proposed CMB observations.