Synopsis
This volume contains the papers published by A. Borel from 1983 to 1999. About half of them are research papers, written singly 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 some surveys, some personal recollections (of D. Montgomery, Harish-Chandra, A. Weil), some 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 parts of the works of H. Weyl, C. Chevalley, E. Kolchin, J. Leray, A. Weil. The volume concludes with an essay on H. Poincaré and special relativity. Some comments on, and corrections to, a number of papers have been added.