No-Nonsense Quantum Field Theory: A Student-Friendly Introduction

Book Preface

When I tried to learn quantum field theory, it was a frustrating experience. When I read the standard textbooks, I felt as if I had hired a climbing coach to show me how to get to the top of Mt. Everest and right after the start he would take my hand, say:  “Watch this!”, and thenmake a huge jump upwards. From one moment to the next I was 100 meters above the ground but had no idea how I got there.

There were no retrospective explanations either, just more and more jumps upwards accompanied by “encouraging” statements that everything is “obvious” or “easy”. It was puzzling and frus­trating.
Most physicists will tell you that it has to be this way. That  this is the only way to understand. I’m convinced that this is nonsense.  Using our Mt. Everest analogy, who do you think will learn more effectively:

– Someone who has watched a world-class climber make in­ credible moves for a few hours and afterwards tries to do them himself,

– or someone who has a coach who takes him through the motions step by step?
I’m not saying that the first approach doesn’t work. It’s obvi­ously extremely popular and currently the standard approach in universities all around the world. But my goal with this book is to provide an alternative that takes an approach which is closer to the second scenario.
In fact, I eventually discovered a textbook that convinced me that a step-by-step approach may not only be possible but can be also enjoyable and effective. The book is called Student Friendly Quantum Field Theory by Robert D. Klauber. It’s a fantastic book and remains to this day my favorite textbook.

Klauber’s book motivated me to write student-friendly text­books on all kinds of topics ranging from classical mechan­ics1 to gauge theory But it also discouraged me from writ­ing a quantum field theory textbook. Instead, I recommended Klauber’s book at every possible occasion to everyone who would listen. I still do.
So why did I eventually write a quantum field theory textbook nevertheless?

I learned a lot about quantum field theory in the past few years and slowly but steadily realized that I would explain most con­cepts completely different than Klauber does in his book. Not necessarily better, but different.3 Therefore, I figured that it won’t hurt anyone if there is a second student-friendly intro­duction to quantum field theory on the market. The readers can still decide which book they prefer and since the books are quite different, it’s possible to read both without getting bored. Every author is able to provide a unique perspective and for any topic you need multiple perspectives to grasp the whole picture.
With that said, let me explain in a bit more detail what makes this book different.