By Rafal Ablamowicz, P. Lounesto

This quantity is devoted to the reminiscence of Albert Crumeyrolle, who died on June 17, 1992. In organizing the quantity we gave precedence to: articles summarizing Crumeyrolle's personal paintings in differential geometry, basic relativity and spinors, articles which provide the reader an idea of the intensity and breadth of Crumeyrolle's study pursuits and impact within the box, articles of excessive medical caliber which might be of basic curiosity. In all of the components to which Crumeyrolle made major contribution - Clifford and external algebras, Weyl and natural spinors, spin buildings on manifolds, precept of triality, conformal geometry - there was enormous growth. Our desire is that the quantity conveys the originality of Crumeyrolle's personal paintings, the continued power of the sphere he motivated, and the iconic appreciate for, and tribute to, him and his accomplishments within the mathematical neighborhood. It isour excitement to thank Peter Morgan, Artibano Micali, Joseph Grifone, Marie Crumeyrolle and Kluwer educational Publishers for his or her assist in preparingthis quantity