3 papers
math.DG2020
Involutive moving frames II; The Lie-Tresse theorem
Örn Arnaldsson
This paper continues the project, begun in \cite{IMF}, of harmonizing Cartan's classical equivalence method and the modern equivariant moving frame in a framework dubbed \emph{invo…
math-ph2020
Invariants of Surfaces in Three-Dimensional Affine Geometry
Örn Arnaldsson, Francis Valiquette
Using the method of moving frames we analyze the algebra of differential invariants for surfaces in three-dimensional affine geometry. For elliptic, hyperbolic, and parabolic point…
math.DG2018
Termination of Cartan's equivalence method
Orn Arnaldsson
We apply the language of the groupoid approach to Lie pseudo-groups, and the classical Cartan-Kuranishi theorem, to prove that Cartan's equivalence method terminates at involution…