Unitary Representations: Schur's Lemma

This lecture covers the concept of unitary representations, focusing on Schur's Lemma, which states that any intertwiner between irreducible unitary representations is either zero or an isomorphism. The lecture explains the irreducibility of representations, the invariance of inner products, and the reducibility of representations. It also discusses the properties of kernels and objectives in the context of unitary representations.