English

A Generalization of von Staudt's Theorem on Cross-Ratios

Algebraic Geometry 2018-07-31 v2 Group Theory Logic

Abstract

A generalization of von Staudt's theorem that every permutation of the projective line that preserves harmonic quadruples is a projective semilinear map is given. It is then concluded that any proper supergroup of permutations of the projective semilinear group over an algebraically closed field of transcendence degree at least 1 is 4-transitive.

Keywords

Cite

@article{arxiv.1803.08520,
  title  = {A Generalization of von Staudt's Theorem on Cross-Ratios},
  author = {Yatir Halevi and Itay Kaplan},
  journal= {arXiv preprint arXiv:1803.08520},
  year   = {2018}
}