The redshifted 21-cm cm line from neutral Hydrogen provides an unique tool for studying the Universe. This radiation appears as a faint background in low frequency radio observations and the measurement of the fluctuations in this background radiation potentially allow us to study the large scale structures in Universe over a very broad range of redshifts. The measurement of this radiation also hold the potential of allowing us to probe the formation of the first galaxies which are believed to have re-ionised the universe. This talk will start with a broad overview of this topic and then present some of the recent research.
Somnath Bharadwaj is Professor of Physics at IIT Kharagpur. His group work in the areas of Astrophysics and Cosmology. His research is currently focused on using low frequency radio telescopes to study the high redshift universe using the redshifted 21-cm radiation from neutral hydrogen. Group is involved in theoretical, computational and also on observational work connected to this issue. (see Prof. Somnath on-line detail pedagogical lecture in astronomy at: http://www.nptelvideos.in/2012/11/ especially on astrophysics & cosmology , also available on utube)