I would like to thank CBMS and NSF for sponsoring the conference; C. Sim-
mons and J. Byrne for the excellent organization; and A. Basmajian, W. Jaco,
E. Rowell, and S. Simon for giving invited lectures. It was a pleasure to lecture
on an emerging field that is interdisciplinary and still rapidly developing. Over
the years I have had the good fortune to work with many collaborators in math-
ematics and physics, including M. Freedman, A. Kitaev, M. Larsen, A. Ludwig,
C. Nayak, N. Read, K. Walker, and X.-G. Wen. Their ideas on the subject and
other topics strongly influence my thinking, especially M. Freedman. He and I have
been collaborating ever since I went to UCSD to study under him two decades ago.
His influence on me and the field of topological quantum computation cannot be
overstated. I also want to thank M. Fisher. Though not a collaborator, repeating
his graduate course on condensed matter physics and having many questions an-
swered by him, I started to appreciate the beautiful picture of our world painted
with quantum field theory, and to gain confidence in physics. He richly deserves
of my apple. In the same vein, I would like to thank V. Jones for bringing me
to his mathematical world, and his encouragement. Jones’s world is home to me.
Last but not least, I would like to thank J. Liptrap for typesetting the book and
correcting many errors, and D. Sullivan for smoothing the language of the Preface.
Of course, errors that remain are mine.