Feynman Path Integral Formulation

Acknowledgements
Over the years I have greatly benefitted from discussions with James Bjorken,
Thibault Damour, Stanley Deser, James Hartle, Hikaru Kawai, Yoshihisa Kitazawa,
Giorgio Parisi, Mike Peskin, Tullio Regge, Gabriele Veneziano and Jean Zinn-
Justin, and many other colleagues, whose insights, benevolent criticisms and encouragements
have affected the content of this work. Most of all I would like to
thank Ruth Williams for her longstanding collaboration on a number of key topics
covered extensively in this book, and for her careful reading of many parts of the
manuscript. I also wish to thank Ido Adam, Hermann Nicolai, Alvaro Restuccia,
Robert Schrader and Stefan Theisen for their diligent reading, constructive criticism
and helpful comments on an early draft of the manuscript. Finally I wish to thank
my students, who over the years were exposed, both in the quantum field theory and
general relativity classes, to some of the topics appearing here now in book form.
The writing of this book would not have been possible without a generous research
grant from the Max Planck Gesellschaft zur Förderung der Wissenschaften.
The author wishes to thank Hermann Nicolai and the staff at the Max Planck Institut
für Gravitationsphysik (Albert-Einstein-Institut) in Berlin-Potsdam for a very warm
hospitality, and a memorable stay.
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