Primitive axial algebras of Jordan type

Abstract

An axial algebra over the field $\mathbb{F}$ is a commutative algebra generated by idempotents whose adjoint action has multiplicity-free minimal polynomial. For semisimple associative algebras this leads to sums of copies of $\mathbb{F}$. Here we consider the first nonassociative case, where adjoint minimal polynomials divide $(x-1)x(x-\eta )$ for fixed $0\ne \eta \ne 1$. Jordan algebras arise when $\eta =\frac{1}{2}$, but our motivating examples are certain Griess algebras of vertex operator algebras and the related Majorana algebras. We study a class of algebras, including these, for which axial automorphisms like those defined by Miyamoto exist, and there classify the $2$-generated examples. For $\eta \ne \frac{1}{2}$ this implies that the Miyamoto involutions are $3$-transpositions, leading to a classification.

41 pages; comments welcome

Cited by in corpus (4)

• Jordan Matsuo algebras over fields of characteristic 3
• Fusion rules from root systems I: case ${\mathrm{A}}_n$
• Miyamoto involutions in axial algebras of Jordan type half
• Associative and Jordan algebras generated by two idempotents