Cosmological signatures of brane inflation

Abstract: Cosmology motivated by string theory has been studied extensively in the recent literature. String theory is promising because it has interesting features such as unifying gravity, electromagnetic, weak and strong nuclear forces. However, even the energy scale of the experiments at the Large Hadron Collider (~TeV) is too low to detect any strong evidence for string theory. The energy scale of inflation can be above ~10^9 TeV. Therefore, it is expected to find some signature of string theory in cosmology. String theory predicts ten space-time dimensions. In the brane world scenario, our four dimensional Universe is confined onto the higher dimensional object called the Brane in the ten dimensional space time. The Dirac-Born-Infeld (DBI) inflation is based on this idea. DBI inflation predicts a characteristic statistical feature in the Cosmic Microwave Background (CMB) temperature anisotropies. In this thesis, we study the predictions of the DBI inflation models on the CMB temperature anisotropies.