Relativistic Quantum Physics: A Complete Guide to Quantum Field Theory and Relativistic Mechanics by Tommy Ohlsson

Introduction

Relativistic quantum physics stands at the crossroads of two monumental pillars of modern science: quantum mechanics and Albert Einstein's special theory of relativity. For students and researchers in India who wish to delve deeply into the fundamental structure of matter and fields, Relativistic Quantum Physics by Tommy Ohlsson offers a rigorous yet accessible pathway. Published by Cambridge University Press, this hardbound volume is an indispensable resource for advanced undergraduate and graduate courses in physics departments across Indian universities.

Book Overview

This textbook seamlessly bridges the gap between relativistic quantum mechanics and introductory quantum field theory. It begins by classifying particles according to their spin and proceeds to develop the Klein–Gordon and Dirac equations with clarity. The narrative then transitions into canonical quantization of scalar, spinor, and electromagnetic fields, laying a solid foundation for understanding how particles interact. Coverage of Yang–Mills theory, the LSZ reduction formalism, and perturbative methods in quantum electrodynamics (QED) ensures that readers are well-prepared for contemporary research. The book also tackles regularization, renormalization, and radiative corrections—topics essential for grasping the predictive power of modern quantum field theories.

Key Highlights

• Comprehensive coverage from relativistic wave equations to quantum field theory in a single volume.
• Step-by-step derivations that make complex mathematical concepts transparent.
• Integrated exercises within each chapter and end-of-chapter problems to reinforce learning.
• Focus on physical interpretation alongside mathematical formalism.
• Up-to-date treatment of gauge theories and renormalization techniques.

Inside the Book

The structure is pedagogically designed: early chapters introduce the need for combining relativity with quantum mechanics, followed by a detailed study of the Klein–Gordon equation and its limitations. The Dirac equation receives special attention, including its solutions, properties, and the concept of antiparticles. Subsequent chapters cover the quantization of free fields, interaction picture, Feynman diagrams, and the S-matrix. A dedicated section on QED processes such as Compton scattering and pair annihilation equips students with practical calculational skills. The final chapters explore renormalization and radiative corrections, offering insight into the subtleties of infinite cancellations that underpin the success of QED.

Key Topics

• Lorentz invariance and classification of particles
• Klein–Gordon and Dirac equations
• Canonical quantization of scalar, Dirac, and electromagnetic fields
• Classical Yang–Mills theory and non-Abelian gauge fields
• LSZ reduction formula and cross-section calculations
• Perturbation theory and Feynman rules in QED
• Regularization methods (Pauli–Villars, dimensional regularization)
• Renormalization of QED at one loop

Reader Benefits

Indian students preparing for competitive exams like JEST, TIFR, GATE, or NET in physics will find this book a treasure trove of conceptual clarity. The exercises are crafted to build problem-solving confidence, while the detailed derivations reduce dependency on multiple reference texts. Researchers transitioning into high-energy physics or quantum field theory will appreciate the self-contained nature of the exposition, which does not assume prior knowledge of advanced topics but gradually builds up to them.

Learning Outcomes

By working through this book, readers will be able to: derive and solve relativistic wave equations; quantize free fields using canonical methods; compute scattering amplitudes in QED using Feynman diagrams; understand the role of gauge symmetry in fundamental interactions; and appreciate the necessity of renormalization in quantum field theory. These skills form the backbone of modern theoretical physics and are directly applicable to research in particle physics, cosmology, and condensed matter theory.

Who Should Read

• Advanced undergraduate students in physics with a background in quantum mechanics and special relativity.
• Graduate students specializing in theoretical physics, high-energy physics, or mathematical physics.
• Researchers and faculty seeking a clear, single-volume reference for teaching or self-study.
• Indian students aiming for careers in academia or research institutes like TIFR, IISc, or IITs.

About the Author

Tommy Ohlsson is a professor of theoretical physics at the Royal Institute of Technology (KTH) in Stockholm, Sweden. His research spans neutrino physics, dark matter, and beyond-Standard-Model phenomenology. With decades of teaching experience, he has authored several acclaimed textbooks that combine mathematical rigor with physical insight. His ability to explain complex ideas in a lucid manner makes this book a trusted companion for learners worldwide.

About the Publisher

Cambridge University Press is one of the oldest and most respected academic publishers in the world. Known for its peer-reviewed content and high editorial standards, Cambridge brings to Indian readers authoritative texts that have shaped scientific education globally. This hardcover edition is printed on quality paper and bound to withstand years of rigorous use in libraries, classrooms, and personal collections.

Conclusion

Relativistic Quantum Physics by Tommy Ohlsson is more than a textbook—it is a gateway to understanding the deepest principles that govern the universe at its most fundamental level. For Indian students and academics who aspire to master the language of modern physics, this book offers a complete, coherent, and challenging journey. Add it to your library today and take a decisive step toward mastering relativistic quantum theory.