ACKNOWLEDGEMENTS 29
Weinberg this project would probably never have been finished. Particular
thanks are also due to Owen Gwilliam, for many discussions which have
greatly clarified the ideas in this book; and to Dennis Sullivan, for his en-
couragement and many helpful comments. I would also like to thank Alberto
Cattaneo, Jacques Distler, Mike Douglas, Giovanni Felder, Arthur Green-
spoon, Si Li, Pavel Mn¨ ev, Josh Shadlen, Yuan Shen, Stephan Stolz, Peter
Teichner, and A.J. Tolland. Of course, any errors are solely the responsibil-
ity of the author.
