Classification of the algebras $\mathbb{O}_{p,q}$

Abstract

We study a series of real nonassociative algebras $\mathbb{O}_{p,q}$ introduced in $[5]$. These algebras have a natural $\mathbb{Z}_2^n$-grading, where $n=p+q$, and they are characterized by a cubic form over the field $\mathbb{Z}_2$. We establish all the possible isomorphisms between the algebras $\mathbb{O}_{p,q}$ preserving the structure of $\mathbb{Z}_2^n$-graded algebra. The classification table of $\mathbb{O}_{p,q}$ is quite similar to that of the real Clifford algebras $\mathrm{Cl}_{p,q}$, the main difference is that the algebras $\mathbb{O}_{n,0}$ and $\mathbb{O}_{0,n}$ are exceptional.