Duplication methods for embeddings of real division algebras
Abstract
We introduce two groups of duplication processes that extend the well known Cayley–Dickson process. The first one allows to embed every 4-dimensional (4D) real unital algebra 𝒜 into an 8D real unital algebra denoted by FD(𝒜). We also find the conditions on 𝒜 under which FD(𝒜) is a division algebra. This covers the most classes of known 4D real division algebras. The second process allows us to embed particular classes of 4D RDAs into 8D RDAs. Besides, both duplication processes give an infinite family of non-isomorphic 8D real division algebras whose derivation algebras contain su(2).
Communicated by L. A. Bokut