Choice Recommended Title, February 2020 This book explores quantum field theory using the Feynman functional and diagrammatic techniques as foundations to apply Quantum Field Theory to a broad range of topics in physics. This book will be of interest not only to condensed matter physicists but physicists in a range of disciplines as the techniques explored apply to high-energy as well as soft matter physics. Features: Comprehensive and rigorous, yet presents an easy to understand approach Applicable to a wide range of disciplines Accessible to those with little, or basic, mathematical understanding