Quantum field theory remains among the most important tools in defining and explaining the microscopic world. Recent years have witnessed a blossoming of developments and applications that extend far beyond the theory's original scope. This comprehensive text offers a balanced treatment, providing students with both a formal presentation and numerous practical examples of calculations.
This two-part approach begins with the standard quantization of electrodynamics, culminating in the perturbative renormalization. The second part comprises functional methods, relativistic bound states,...

A comprehensive and timely survey of the application of the methods of quantum field theory to statistical physics, a very active and fruitful area of modern research, is provided in two volumes. The first volume provides a pedagogical introduction to the subject, discussing Brownian motion, its anticommutative counterpart in the guise of Onsager's solution to the two-dimensional Ising model, the mean field or Landau approximation, scaling ideas exemplified by the Kosterlitz-Thouless theory for the XY transition, the continuous renormalization group applied to the standard phi-to-the-fourth...

The second volume covers diverse topics, including strong coupling expansions and their analysis, Monte Carlo simulations, two-dimensional conformal field theory, and simple disordered systems. The book concludes with a chapter on random geometry and the Polyakov model of random surfaces, which illustrates the relations between string theory and statistical physics.