Introduction to division algebras, sphere algebras and twistors

Konferensbidrag (offentliggjort, men ej förlagsutgivet), 1993

A very basic introduction is given to the roles of division algebras and the related sphere algebras concerning the structure of space-time in the dimensionalities D=3,4,6 and 10, with special emphasis on twistors transformations for light-likeness conditions and Hopf maps, together with some outlook for particle and string theory.