English

Tools for analyzing the intersection curve between a torus and a quadric through projection and lifting

Algebraic Geometry 2025-03-13 v1

Abstract

This article introduces efficient and user-friendly tools for analyzing the intersection curve between a ringed torus and an irreducible quadric surface. Without loose of generality, it is assumed that the torus is centered at the origin, and its axis of revolution coincides with the zz-axis. The paper primarily focuses on examining the curve's projection onto the plane z=0z=0, referred to as the cutcurve, which is essential for ensuring accurate lifting procedures. Additionally, we provide a detailed characterization of the singularities in both the projection and the intersection curve, as well as the existence of double tangents. A key tool for the analysis is the theory of resultant and subresultant polynomials.

Keywords

Cite

@article{arxiv.2503.08924,
  title  = {Tools for analyzing the intersection curve between a torus and a quadric through projection and lifting},
  author = {Laureano Gonzalez-Vega and Jorge Caravantes and Gema M. Diaz-Toca and Mario Fioravanti},
  journal= {arXiv preprint arXiv:2503.08924},
  year   = {2025}
}
R2 v1 2026-06-28T22:16:51.437Z