A new series of axial algebras of Monster type (2eta ,eta )

Abstract

We construct a new series of n^2-dimensional axial algebras of Monster type (2eta ,eta ). They arise as subalgebras A of the Matsuo algebras M_eta (^-O_{n+1}^+(3)), generated by single and double axes. Also, we address the question of when these algebras are simple. While we do not solve this question, we formulate three concrete conjectures based on the calculation, using the computer algebra system GAP, of the roots of the determinant of the Gram matrix of the Frobenius form on A for several small values of n.