About this series
C.I.M.E. stands for Centro Internazionale Matematico Estivo, that is, International Mathematical Summer Centre. Conceived in the early fifties, it was born in 1954 in Florence, Italy, and welcomed by the world mathematical community: it continues successfully, year for year, to this day. These historical reproductions of the summer school texts originally published by C.I.M.E., from the beginning in 1954 until 1980, complete the C.I.M.E. collection at Springer. Since 1981 they have been published in the Fondazione C.I.M.E. subseries of the Lecture Notes in Mathematics. NOTE: "The CIME summer school volumes digitized in this collection are, in their original form, for the most part typescripts, incorporating hand-written formulae or other annotation in many texts, then duplicated using a hand-duplicating machine at the University of Florence Mathematics Institute, all of this using technology from the 1950s to 1970s. We apologize for resulting imperfections on certain pages. We believe the quality and interest of the content compensates for these and justify their reproduction in the present editions." Professor Pietro Zecca, Director, C.I.M.E.