Quantum Field Theory  is a framework that applies quantum principles to the classical theory of fields. It treats particles as quantized excitations of continuous fields defined over space-time. Interactions occur through local couplings of these fields, replacing classical point particles with operator-valued functions. QFT respects both quantum mechanics and special relativity. It ensures causality by demanding that field operators commute at spacelike separations. This framework forms the basis of the Standard Model of particle physics.

Session 1: introduction to QFT, mostly focusing on when do we need the migration from regular quantum mechanics to quantum field theory.

Session 2: This Section focuses on the concept of symmetry and conserved currents which is known as Noether’s theorem. 

Session 3 : This session focus on the Concept of “Quantization” and how to transforms classical ideas to “Hilbert space” to be able to have a quantum description.

Session 4: This session focus on the concept of “Causality” and propagator and the idea of Klein-Gordon field can solve the quality problem in relativistic particle quantum mechanics.

Session 5: This session is about Dirac Algebra in classical Dirac equation. It is an introduction how anti commuting nature can be introduced to the classical fields. 

Session 6: In this session we will see how to write down a “representation” of a Lorentz transformation in spinor space. We see how momentum boost and rotation in spinor space are interconnected and how the concept of spin can naturally be incorporated within the field.

Session 7:This session is about the connection of Angular momentum and spin and how the total angular momentum is defined out of both of them. We also talk about the concept of a field defined on manifold and how it transforms through the geometry of manifold. We explain how spin is different from regular object that rotates under SO(1,3) and how spin is like Möbius band defined object.

Session 8: In this session, we focus on the anticommutator algebra and the meaning of fermions with respect to bosons. The Pauli exclusion principle naturally emerges from the Dirac algebra. This principle states that no two identical fermions can occupy the same quantum state simultaneously. It explains the structure of electron shells in atoms and underlies the stability of matter. In contrast, bosons obey commutation relations and can occupy the same state, leading to phenomena like Bose-Einstein condensation.

Session 9: This video explains how to calculate the Dirac propagator using the Green’s function method, a technique rooted in classical theory. It walks through each step of setting up the problem in the context of quantum field theory. The use of Green’s functions helps translate differential equations into solvable integral forms. A major part of the process involves evaluating complex integrals that appear naturally in the formalism. The video applies the residue theorem from complex analysis to perform these calculations.

Session 10: In this video we discuss three forms of discrete symmetries which are different in nature with continues transformation like translation rotation or boost. We introduced the concept of parity to categorize two types of behavior under parity, odd or even parity. We also talk about combination of these symmetries and how weak interaction violates CP symmetries while the two other interaction, QED and QCD do not violate CP.