This book collects the papers published by A. Borel from 1983 to 1999. About half of them are
research papers written on his own or in collaboration on various topics pertaining mainly to
algebraic or Lie groups homogeneous spaces arithmetic groups (L2-spectrum automorphic forms
cohomology and covolumes) L2-cohomology of symmetric or locally symmetric spaces and to the
Oppenheim conjecture. Other publications include surveys and personal recollections (of D.
Montgomery Harish-Chandra and A. Weil) considerations on mathematics in general and several
articles of a historical nature: on the School of Mathematics at the Institute for Advanced
Study on N. Bourbaki and on selected aspects of the works of H. Weyl C. Chevalley E. Kolchin
J. Leray and A. Weil. The book concludes with an essay on H. Poincaré and special relativity.
Some comments on and corrections to a number of papers have also been added.
