Explore the foundations of modern cosmology in this comprehensive lecture by renowned physicist Nima Arkani-Hamed, part of the Kavli Asian Winter School on Strings, Particles and Cosmology 2018. Delve into topics such as quantum mechanical observables, the wave function of the universe, and cosmological correlation functions. Examine the concept of inflation as a cosmological collider and its implications for particle physics. Investigate key concepts like Lagrangians, polarization vectors, and four-point functions. Gain insights into cutting-edge research and theoretical developments in the field of cosmology through this in-depth, 1 hour and 39 minute presentation from the International Centre for Theoretical Sciences.