Lorenz Halbeısen

collaborators

3 papers

math.AG2023

Properties of Hesse derivatives of cubic curves

Sayan Dutta, Lorenz Halbeisen, Norbert Hungerbühler

The Hesse curve or Hesse derivative Hess $(Γ_{f})$ of a cubic curve $Γ_{f}$ given by a homogeneous polynomial $f$ is the set of points $P$ such that $det (H_{f} (P)) = 0$ , whe…

math.LO2023

Implications of Ramsey Choice Principles in ZF

Lorenz Halbeisen, Riccardo Plati, Saharon Shelah

The Ramsey Choice principle for families of $n$ -element sets, denoted $RC_{n}$ , states that every infinite set $X$ has an infinite subset $Y \subseteq X$ with a choice functi…

math.NT2023

Halving formulae for points on elliptic curves

Lorenz Halbeisen, Norbert Hungerbuehler

Let $P$ be an arbitrary point on an elliptic curve over the complex numbers of the form $y^{2} = x^{3} + a_{4} x + a_{6}$ or of the form $y^{2} = x^{3} + a_{2} x^{2} + a_{4} x$ . We provide explicit formulae…