9th International Congress on Fundamental and Applied Sciences 2022 (ICFAS2022) , İstanbul, Türkiye, 28 - 30 Haziran 2022, cilt.1, ss.115
We present a computational method to detect affine equivalences of implicit plane algebraic
curves. The method proceeds by first reducing the problem to the case of affine equivalences
where the orgin is fixed, using the Hessian curves of the input curves. Then, the Hessian is
again used to derive certain differential invariants that allow us to compute the components of
the equivalences by just using resultants and polynomial factoring. In special cases, for
instance curves with infinitely many self-affine equivalences, equivalences are computed
using a more direct method involving polynomial system solving, but with polynomials of
smaller degree. A comparison of the algorithm with other methods, including brute force, is
also given.