Quantum Weinberg and his QM and QFT books

[FourEyedRaven]

Hi,

Two questions.

Are Weinberg's "Lectures on Quantum Mechanics" a bridge to his QFT books? I read that his QFT volumes are excellent books, but not for the beginner. So, if I want to begin QFT, can I choose his "Lectures on Quantum Mechanics" for a graduate level QM book, and make the transition easier? Or is there just no way around learning QFT from an easier source before reading Weinberg's volumes?

A second question is: why are his QFT books so difficult? Is it because of the advanced mathematics, the abstract treatment, the knowledge or maturity assumed, the pace? What is it exactly?

Thank you in advance and happy new year everybody.

4ER

 

[vanhees71]

The level of Weinberg's books is high, because he is very comprehensive. E.g., in his QFT books he starts with the derivation of all physically relevant unitary representations of the Poincare group. For the beginner that's too abstract to start with this anyway quite abstract subject. His QM book doesn't help starting with his QFT books any more than any good QM book helps to learn the fundamental concepts of QT needed to start with QFT. Don't get me wrong: Weinberg's textbooks (I know his QFT books, the QM book, and the two books on GR and cosmology) are the best textbooks I've ever seen about these subjects. Particularly to really understand relativistic QFT, there's no other way than to learn about the unitary representations of the Poincare group (as there's no other way to really understand non-relativistic QM than to learn about the unitary ray representations of the Galileo group either).

To really appreciate these comprehensibility and completeness of Weinberg's QFT books, it's however helpful to have some preknowledge from somewhat easier QFT books. My favorite for that purpose is

M. D. Schwartz, Quantum Field Theory and the Standard Model, Cambridge University Press (2014)

QFT, however, is a very wide field (it's safe to say that nearly all physics is described by QFT, except gravitation, where no really convincing QFT description (yet) exists), and even Weinberg's books leave out interesting topics. Thus another book, equally well written as and complementary with Weinberg's, is

A. Duncan, The conceptual framework of Quantum Field Theory, Oxford University Press (2012)