A concise, beginner-friendly introduction to quantum field theory. Quantum field theory is a powerful framework that extends quantum mechanics in ways that are essential in many modern applications. While it is the fundamental formalism for the study of many areas of physics, quantum field theory requires a different way of thinking, and many newcomers to the subject struggle with the transition from quantum mechanics. A Prelude to Quantum Field Theory introduces the key concepts of quantum field theory in a brief and accessible manner while never sacrificing mathematical rigor. The result is an easy-to-use textbook that distills the most general properties of the theory without overwhelming beginning students with more advanced applications.Bridges quantum mechanics and quantum field theory, emphasising analogies and differencesEmphasises a 'quantum field theoretical mindset' while maintaining mathematical rigorObtains quantum fields as the continuum limit of a quantised system of many particlesHighlights the correspondence between wave function—fundamental in quantum mechanics—and the formalism of second quantisation used in quantum field theoryProvides a step-by-step derivation of Feynman rules for the perturbative study of interacting theoriesIntroduces students to renormalisation, path integrals techniques, and moreDiscusses more modern topics like effective field theoriesIdeal for both undergraduate and graduate studentsProven in the classroom'A robust, hands-on introduction to quantum field theory for undergraduate students. Donoghue and Sorbo know this material inside and out.' — C. P. Burgess, author of Introduction to Effective Field Theory'Donoghue and Sorbo present the conceptual aspects of field theory clearly and accessibly, without dragging students into heavy formalism. There is a real need for a book like this.' — Surjeet Rajendran, Johns Hopkins University