Misha Shubin made many seminal contributions to Spectral Theory and Geo-
metric Analysis. He is also an outstanding teacher: he directed nearly twenty
Ph.D. dissertations, and influenced many young mathematicians who were not his
students. His book Pseudodiﬀerential Operators and Spectral Theory, written more
than 30 years ago, is still a standard textbook.
Mikhail Shubins 65th Birthday was celebrated at a conference titled Spectral
Theory and Geometric Analysis held at Northeastern University in Boston in the
summer of 2009. The speakers at this conference were leading mathematicians
working in Global Analysis. The call for papers for this volume went to all partic-
ipants of the conference.
We would like to thank the authors who contributed to this volume as well as
those who served as referees.