Correlation Functions of Harmonic Oscillator

This lecture covers correlation functions of the harmonic oscillator, the Wick theorem, and perturbation theory for the anharmonic oscillator. It delves into free point correlators in the context of quantum field theory, Gaussian integrals, and graphical notations. The instructor explains the concept of functional methods, Dirichlet boundary conditions, and the thermal partition function. The lecture concludes with a discussion on perturbation theory, the anharmonic oscillator potential, and the Euclidean correlation functions.