Aspects of Symmetry: Selected Erice Lectures

Coleman's Erice lectures on Instantons and his bacteria model of the Callan–Symanzik renormalization group equation, made a big impact on me when I was doing my Ph.D. It's very nice to have them easily accessible in the same book.

A classic from a great physicist.

This book's most valuable points are its treatment of renormalization and non-perturbative effects in quantum field theory. Although the renormalization discussion does not get to the heart of Wilson's conceptual picture, it provides a coherent picture of the renormalization procedure without cluttering the pages with computations (a la Peskin/Schroeder).The section on instantons (ch. 7) is almost entirely self-contained, beginning with an analysis of classical mechanics, slowly ascending to quantum field theory. A few of the earlier chapters are on topics that were hot in the 60s and 70s, so you may not want to spend the money for a book where only ~1/2 of the pages are currently relevant, especially considering the fact that it's a bit expensive.Also, don't expect any spectacular insights into QCD, as most lectures in the book predate or are concurrent with the advent of the field.

These are excellent lectures by a master theoretical physicist. Nobody understood quantum field theory as clearly as Nicole (nickname of S. Coleman: yes, he was gay) did. Of course, there have been advances in the field, but these lectures are still useful. Besides, QFT has advanced very little in the last 40 years. Sure, there have been phenomenological advances, but the theory is still in the same state as in 1980. In particular, the QCD confinement problem still needs to be solved, so most of the "progress" is propaganda.

Every time I've looked at this book, I have been struck by how extraordinarily good the writing is and how it makes the physics understandable and memorable.

This 400-page book contains eight lectures of varying length (some are quite long). The first two are not very useful, but the remainder of the book is wonderful. It covers topics like scale invariance, Callan-Symanzik (RG) equations, renormalization theory (Hepp's theorem), spontaneously broken symmetries, classical and quantum solitons, instantons (in QM and in gauge theories), and 1/N expansion. These are all useful topics and must be understood by those in the field, and yet not all of them are covered by ordinary quantum field theory books like Peskin & Schroeder. The style is very friendly and readable and includes a lot of endnotes, appendices, and references. This book does not "read" like Peskin/Schroeder or Weinberg or Itzykson/Zuber; those books don't read. This one does. The equations are easy to follow and this book showcases the strength of Coleman's pedagogical style. In fact I can vouch that the tone and content of these lectures serves as a close substitue for Coleman's lectures themselves. The topics were all basically developed in the 1970s, and were themselves all quite hot research areas before supersymmetry and string theory revolutionized high-energy physics. However, the majority of this book is not an anachronism -- the renormalization group, spontaneously broken symmetries, solitons, instantons, and 1/N expansion all pervade modern physics.

Coleman is one of the best field theorists and a great lecturer. His style in both research and lectures can be summarized as "turning obvious into trivial". Every topic is presented in the simplest possible way without loss of deep insights, which makes the book extremely comprehensible. The chapter on instantons is absolutely classic.

The stuff on symmetry breaking was nice and the section on solitons was helpful. However I found the first couple of lectures so outdated as to be destructive to my understanding.