Graphs, Axial Algebras and their Automorphism Groups

Hans Cuypers

doi:10.1016/j.jalgebra.2026.02.013

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arXiv · 2603.03822

Graphs, Axial Algebras and their Automorphism Groups

Hans Cuypers

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Abstract

We introduce a class of algebras over a field $\mathbb{F}$ related to directed graphs in which all edges are labeled by nonzero elements of the field $\mathbb{F}$. If all labels are different from $1$, these algebras are axial algebras. We determine their fusion laws, prove them to be simple in almost all cases, and determine their automorphism group under some conditions on the degrees and girth of the graph. A construction of a class of these graphs with prescribed automorphism group enables us to construct for each group $G$ infinitely many simple (axial) algebras (with a fixed fusion law) such that the automorphism group of the algebra is isomorphic to $G$.

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Hans Cuypers. 2026-03-04. Graphs, Axial Algebras and their Automorphism Groups. https://doi.org/10.1016/j.jalgebra.2026.02.013

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