I am an undergraduate from IISER Pune, working under the guidance of Prof. Suvrat Raju, for my Master's thesis. My work concerns with using Bell's Inequality, to identify the origin of primordial fluctuations as classical or quantum in nature.

Many of the puzzling problems in cosmology including the horizon problem, the flatness problem and the homogeneity problem are satisfactorily solved by the idea of inflation. Inflation is the exponential expansion of space-time about after 10^(-43)s after the birth of the universe, driven by a slow rolling scalar field. An important prediction of the theory of inflation is that quantum fluctuations in the early Universe leave their imprint on the Cosmic Microwave Background (CMB), and measuring these correlators allows us to detect the structure of those primordial fluctuations. However, an important question is to determine whether these initial fluctuations simply arise from a classical probability distribution, or whether they are genuinely quantum in origin. And, one way to be able to differentiate between the classical and quantum mechanical models is to use Bell’s Inequality. Observables (and mechanisms) are sought, such that their correlation functions that are experimentally measurable from the CMB will tell us which of the proposed models are true. My project concerns with the understanding of application of Bell’s Inequality for the above mentioned purpose and possible observables and mechanisms that make such measurements possible.