DR. PRABHAKAR TIWARI

The ``Cosmological Principle'' assumes homogeneity and isotropy at large distance scales. This is a fundamental assumption in our standard cosmological framework and therefore must be tested explicitly by observations. In this talk, the speaker will review some great (bizarre, famous, significant!) observations of large scale isotropy/anisotropy achieved by employing radio galaxy surveys. In particular, he will present the radio galaxy number count dipole and the latest dipole–quadruple–octopole alignment results from NVSS+SUMSS catalogs. He will discuss a few more observations of large scale isotropy/anisotropy and the existing theoretical proposals to explain these. At present there are several major radio galaxy observations available e.g. LOFAR surveys, TGSS, GLEAM etc. and we have a lot to explore from these observations, later on we are going to have Square Kilometre Array (SKA) observations. With SKA all radio physics is going to benefit immensely, the speaker will discuss how much improvement we are expecting to have on isotropy/anisotropy observations with upcoming SKA observations.