11 citations · 21 across the 15 of their papers we have counts for
4 papers · 1 filter
Polyfunctions over Commutative Rings
Ernst Specker, Norbert Hungerbühler, Micha Wasem
A function , where is a commutative ring with unit element, is called polyfunction if it admits a polynomial representative . Based on this notion we intro…
Reversion Porisms in Conics
Lorenz Halbeisen, Norbert Hungerbühler, Marco Schiltknecht
We give a projective proof of the butterfly porism for cyclic quadrilaterals and present a general reversion porism for polygons with an arbitrary number of vertices on a conic. We…
The Ring of Polyfunctions over
Ernst Specker, Norbert Hungerbühler, Micha Wasem
We study the ring of polyfunctions over . The ring of polyfunctions over a commutative ring with unit element is the ring of functions which ad…
A geometric approach to elliptic curves with torsion groups , , , and
Lorenz Halbeisen, Norbert Hungerbuehler, Maksym Voznyy +1
We give new parametrisations of elliptic curves in Weierstrass normal form with torsion groups and over $\math…