English

On the Enumerative Geometry of Pascal's Hexagram

Algebraic Geometry 2023-03-21 v1

Abstract

Given six points A,B,C,D,E,FA,B,C,D,E,F on a nonsingular conic in the complex projective plane, Pascal's theorem says that the three intersection points AEBF,BDCE,ADCFAE \cap BF, BD \cap CE, AD \cap CF are collinear. The line containing them is called a pascal, and we get altogether 6060 such lines by permuting the points. In this paper, we consider the enumerative problem of finding the number of sextuples (A,B,,F)(A, B, \dots, F) which correspond to three pre-specified pascals. We use computational techniques in commutative algebra to solve this problem in all cases. The results are tabulated using the so-called 'dual' notation for pascals, which is based upon the outer automorphism of S6S_6.

Keywords

Cite

@article{arxiv.2303.10319,
  title  = {On the Enumerative Geometry of Pascal's Hexagram},
  author = {Jaydeep Chipalkatti},
  journal= {arXiv preprint arXiv:2303.10319},
  year   = {2023}
}
R2 v1 2026-06-28T09:22:18.523Z