Explore the intricacies of de Sitter space in this advanced physics lecture delivered by Dionysios Anninos from King's College London. Delve into the classical and quantum aspects of asymptotically de Sitter spacetimes, examining the late time de Sitter wavefunction and the dS/CFT correspondence. Investigate a concrete example involving Vasiliev theory with interacting massless gauge higher spin fields. Compare and contrast the cosmological dS horizon with a standard black hole horizon. Topics covered include quantization, CMB-like calculations, unitary groups SO(1,4), non-zero spin, quantum states, and wave function structure, followed by a Q&A session.