Alex Gezerlis is Professor of Physics at the University of Guelph. Before moving to Canada, he worked in Germany, the United States, and Greece. He has received several research awards, grants, and allocations on supercomputing facilities. His research interests range from nuclear forces, structure, and astrophysics, to ultracold atoms. He has taught courses on quantum field theory, computational methods, subatomic physics, and science communication. He is also the author of Numerical Methods in Physics with Python, 2nd edition (Cambridge University Press, 2023).

• Preface; Part I. Preliminaries: 1. Relativistic Notation; 2. Single-Particle Quantum Mechanics; 3. Classical Mechanics; Problems for Part I; Part II. Classical Scalar Field Theory: 4. Lagrangian Field Theory; 5. Symmetry; 6. Hamiltonian Formalism; 7. Field-Equation Solution; Problems for Part II; Part III. Quantization of Non-Interacting Scalar Fields: 8. Harmonic Oscillators; 9. Changing Pictures; 10. Canonical Quantization; 11. Transformation Properties; 12. Causality and Propagators; 13. Interacting Theory: First Attempt; Problems for Part III; Part IV. Electromagnetic Field: 14. Classical Electromagnetism; 15. Gauge Invariance; 16. Quantizing Electrodynamics; Problems for Part IV; Part V. Quantization of Interacting Fields: 17. Interaction Picture; 18. Interacting Theory: Second Attempt; 19. How to be Weak; 20. Scattering Preliminaries; 21. Old-Fashioned Scattering; 22. Lorentz Invariance; 23. Cluster Decomposition; 24. Wick's Theorem; 25. 1-1 Process; 26. Feynman Diagrams; 27. Vacuum-Vacuum Diagrams; 28. Momentum Space; 29. 2-2 Process; 30. Mass Renormalization; 31. Coupling Renormalization; 32. Renormalization Redux; 33. Renormalization Group; 34. Hidden Symmetry; Project: Scalar Electrodynamics; Problems for Part V; Appendix: Group Theory; References; Index.

'My complaint about most introductions to quantum field theory is that they are primarily cookbooks: they tell you much about the how, but very little about the why. Gezerlis' book is a dazzling exception. The essential role of the cluster decomposition principle, rarely discussed in other books, receives the full chapter it deserves. But technical aspects are not overlooked, either—witness, for example, a careful explanation of the Wick rotation. I wish I could have read this book as an advanced undergraduate or beginning graduate student.' Ubirajara van Kolck, European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*)