Axes in non-associative algebras

Axes in non-associative algebras

“Fusion rules” are laws of multiplication among eigenspaces of an idempotent. This terminology is relatively new and is closely related to axial algebras, introduced recently by Hall, Rehren and Shpectorov. Axial algebras, in turn, are closely related to 3-transposition groups and Vertex operator algebras. In this paper we consider fusion rules for semisimple idempotents, following Albert in the power-associative case. We examine the notion of an axis in the non-commutative setting and show that the dimension d of any algebra A generated by a pair a, b of (not necessarily Jordan) axes of respective types (λ, δ) and (λ ′ , δ ′ ) must be at most 5; d cannot be 4. If d ≤ 3 we list all the possibilities for A up to isomorphism. We prove a variety of additional results and mention some research questions at the end.

___

  • [1] Albert AA, Power-associative rings. Transactions of the Amererican Mathematical Society 1948; 64: 552–593.
  • [2] De Medts T, Peacock SF, Shpectorov S, and Van Couwenberghe M, Decomposition algebras and axial algebras. Journal of Algebra 2020; 556: 287–314.
  • [3] Hall JI, Rehren F, Shpectorov S, Primitive axial algebras of Jordan type, Journal of Algebra 2015; 437: 79–11.
  • [4] Hall JI, Segev Y, Shpectorov S, Miyamoto involutions in axial algebras of Jordan type half, Israel Journal of Mathematics 2018; 223: 261–308.
  • [5] Rowen L, Segev Y, Axes of Jordan type in non-commutative algebras, submitted. J. Algebra Appl.
  • [6] Schafer RD, non-commutative Jordan algebras of characteristic 0, Proceedings of the American Mathematical Society 1955; 6: 472–475.
  • [7] Shestakov, I, Trushina, M, Irreducible bimodules over alternative algebras and superalgebras. Trans. Amer. Math. Soc. 2016; 368: 4657–4684.