Anti-rotors and algebra invariants
Fred Greensite
TL;DR
The paper introduces a novel framework of algebraic invariants based on transformations tied to the bilinear product of real finite-dimensional unital associative algebras. Central to the approach are the Skewer map and the anti-rotor, whose uncurling metrics yield a rich family of invariants, including the anti-rotor dimension, ranks, and a dual space of unital norms that induce logarithmic and quadratic geometries on algebras. The authors develop a functorial view linking algebras to their anti-rotors, provide explicit computations for low-dimensional and structured algebras (e.g., Toeplitz, direct-product, and triangular algebras), and define Type I and Type II anti-rotors to organize an infinite landscape of potential invariants. Collectively, these results offer a new, differentiable lens on algebra structure, with tractable invariants and explicit norm geometries that extend beyond classical norms and ideals, potentially aiding classification and comparison of algebras. The work also outlines conjectures about the universality of anti-rotors across function families and orders, inviting further exploration and computational verification across broader algebra classes.
Abstract
We derive previously unrecognized geometrically-based isomorphism invariants for real finite-dimensional unital associative algebras, resulting from examination of transformations from an algebra to itself that are dependent on the algebra's bilinear product operation.
