In this book, Susan Hegeman focuses on the term's history in the United States in the first half of the twentieth century. This text begins with a review of classical mechanics, Hilbert space, quantum mechanics and scalar quantum field theory. Next, analytical skills are further developed, a special class of models is studied, and a discussion of continuous and discontinuous perturbations is presented.
Later chapters cover two further classes of models both of which entail discontinuous perturbations.
The final chapter offers a brief summary, concluding with a conjecture regarding interacting covariant scalar quantum field theories. Symmetry is repeatedly used as a tool to help develop solutions for simple and complex problems alike. Challenging exercises and detailed references are included. These problems are significant and need to be faced. The material in this text is designed to offer one view, and a rather conservative one at that, of just such an enlarged viewpoint on how quantum field theory may be formulated with an eye to dealing with hitherto insoluble problems.