Preface

This is the second in a series of a few short books about the foundations of quantum field theory.

We would like to acknowledge here the contribution to parts of the material contained within this book by former students and collaborators who were active in this subject in the past: Dr. Timothy Edward Gallivan and Dr. André Cavalcanti Rocha Martins. When appropriate, due credit will be given in footnotes along the text. We would also like to thank those that helped by reading and correcting the manuscript at various stages of its production.