Weighing the Universe with Deuterium

The thesis focuses to test Big Bang model beyond the standard model of Physics and cosmology by putting sensitive constraints on parameters. This constraint is obtained by measuring primordial D/H from the diffuse clouds of gas illuminated by quasars which is not easily available. Therefore, the research identifies maximum number of systems with accurate and precise measurements of D/H by preliminary analyzing 12 such systems and detailed analysing 4 of them. All systems are prioritized which would help future researchers to use this information to initiate detailed analysis of other systems and improve the obtained results.