Symmetric composition algebras over algebraic varieties

We assume 2 and 3 to be invertible elements in the base ring. The structure of symmetric composition algebras over locally ringed spaces and thus in particular over rings is investigated. Symmetric composition algebras are constructed on the trace 0 elements of cubic alternative algebras over a locally ringed space, if the global sections of the space contain a primitive third root of unity, generalizing a method first presented by J. R. Faulkner. We find examples of Okubo algebras over elliptic curves which cannot be made into octonion algebras.

S. Pumpluen < susanne.pumpluen@nottingham.ac.uk >