Future Outlook on Primordial Gravitational Waves

Cosmic inflation predicts primordial density fluctuations that are consistent with the observed temperature fluctuations. Inflation predicts quantum fluctuations in the fabric of spacetime itself. These primordial gravitational waves lead to a characteristic imprint in CMB polarization, commonly referred to as B-mode polarization, and many of the best-motivated models predict a signal that is large enough to be detected with LiteBIRD (the Lite (Light) satellite for the study of B-mode polarization and Inflation from cosmic background Radiation Detection). This thesis provides an overview of the LiteBIRD mission, including its scientific objectives and its expected role in constraining primordial gravitational waves. In particular, a comprehensive analysis is performed to investigate the tensor-to-scalar ratio and the tensor spectral index nt.