Applications of quantum field theoretical methods to gravitational physics, both in the semiclassical and the full quantum frameworks, require a careful formulation of the fundamental basis of quantum theory, with special attention to such important issues as renormalization, quantum theory of gauge theories, and especially effective action formalism. The first part of this graduate textbook provides both a conceptual and technical introduction to the theory of quantum fields. The presentation is consistent, starting from elements of group theory, classical fields, and moving on to the effective action formalism in general gauge theories. Compared to other existing books, the general formalism of renormalization in described in more detail, and special attention paid to gauge theories. This part can serve as a textbook for a one-semester introductory course in quantum field theory.

In the second part, we discuss basic aspects of quantum field theory in curved space, and perturbative quantum gravity. More than half of Part II is written with a full exposition of details, and includes elaborated examples of simplest calculations. All chapters include exercises ranging from very simple ones to those requiring small original investigations. The selection of material of the second part is done using the "must-know" principle. This means we included detailed expositions of relatively simple techniques and calculations, expecting that the interested reader will be able to learn more advanced issues independently after working through the basic material, and completing the exercises.

About the Author:
Joseph Buchbinder, Department of Theoretical Physics, Tomsk State Pedagogical University, Ilya Shapiro, Departamento de Fisica - ICE, Universidade Federal de Juiz de Fora

Ioseph Buchbinder graduated from Tomsk State University (Russia) with the highest degree (1988, doctor of sciences) in Physical and Mathematical ciences. From 1988 to the present time, he is a professor and head of Department of Theoretical Physics at Tomsk State Pedagogical University. He was a visiting professor at University of Pennsylvania, University of Maryland, University of North Carolina, University of Hannover, Humboldt University Berlin, Cambridge University, University of Sao Paulo, University of Juiz de Fora, University of Hiroshima, Wroclaw University, University of Brno, University of Beer Sheva. Was a supervisor of 21 Ph.D thesis, co-author of Effective Action in Quantum Gravity (IOPP, 1992; with S.D. Odintsov and I.L. Shapiro) and Ideas and Methods of Supersymmetry and Supergravity (IOPP, 1995, 1998; with S.M. Kuzenko), and author of around 300 papers in Statistical Mechanics, Quantum Field Theory, Quantum Gravity, Supersymmetry and Supergravity, and Higher Spin Field
Theory.

Ilya Shapiro graduated from Tomsk State University Physics (Russia) with the highest degree (1993, doctor of sciences) in Physical and Mathematical Sciences. In 1994-1996 was post-doc in the Department of Theoretical Physics in the University of Zaragoza, from 1996 visiting and from 2000 permanent professor at the Federal University of Juiz de Fora, Brazil. In 2014 he was visiting professor at the University of Geneva. Between 1985 and 2020 he supervised 13 Ph.D. theses, and has been author and co-author of 150+ articles and three books, including Effective Action In Quantum Gravity (IOPP, 1992), an introductory textbook on Newtonian Mechanics (two editions, in Brazil and in Germany), and an introductory textbook on Tensors and Relativity (Springer, 2019).