English

Korchagin's third conjecture

Algebraic Geometry 2016-11-24 v1

Abstract

We consider the MM-curves of degree nine with three nests 1αi,i=1,2,31 \langle \alpha_i \rangle, i = 1, 2, 3 in RP2\mathbb{R}P^2. After systematic constructions, Korchagin conjectured that at least two of the αi\alpha_i must be odd. It was later proved that there is always one odd αi\alpha_i. We say that the curve has a jump in a non-empty oval OO if there exist four ovals A,B,C,DA, B, C, D, with AA interior to some other non-empty oval OO', DD exterior, B,CB, C interior to OO, such that BB and CC are separated inside of OO by any line passing through AA and DD. In this paper, we prove the conjecture for the curves without jump, and we find restrictions on the complex orientations and rigid isotopy types admissible for the curves even, even, odd with jump.

Keywords

Cite

@article{arxiv.1611.07815,
  title  = {Korchagin's third conjecture},
  author = {Séverine Fiedler-Le Touzé},
  journal= {arXiv preprint arXiv:1611.07815},
  year   = {2016}
}

Comments

63 pages, 39 figures, 18 tables

R2 v1 2026-06-22T17:02:19.682Z