Weinberg's textbook on quantum field theory, titled "The Quantum Theory of Fields," is considered one of the most comprehensive and authoritative resources on the subject. It is a three-volume series that covers a wide range of topics in quantum field theory (QFT) with a focus on quantum electrodynamics (QED) and the standard model of particle physics.
The series provides a rigorous mathematical treatment of QFT, covering both the conceptual foundations and the technical aspects of the theory. It is known for its mathematical depth, clarity of explanations, and attention to detail. Weinberg's writing style is often considered concise and precise, making it suitable for advanced students and researchers in theoretical physics.
However, it's important to note that Weinberg's textbook on QFT is primarily focused on particle physics and the standard model, rather than quantum gravity specifically. While it covers topics such as renormalization and gauge theories that are relevant to quantum gravity, it does not delve deeply into the specifics of quantum gravity itself, such as string theory or loop quantum gravity.
For a comprehensive understanding of quantum gravity, you may want to explore other resources that specifically address the topic. Some notable textbooks on quantum gravity include "Quantum Gravity" by Carlo Rovelli, "String Theory and M-Theory" by Katrin Becker, Melanie Becker, and John H. Schwarz, and "Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics" by Robert M. Wald.
In summary, Weinberg's "The Quantum Theory of Fields" is an excellent resource for studying quantum field theory and its applications in particle physics. While it provides a solid foundation for understanding the mathematical aspects of QFT, if your main interest is quantum gravity, you may want to supplement your studies with textbooks that specifically focus on that subject.