English

Real inflection points of real hyperelliptic curves

Algebraic Geometry 2018-10-05 v2 Combinatorics

Abstract

Given a real hyperelliptic algebraic curve XX with non-empty real part and a real effective divisor \mcD\mc{D} arising via pullback from P1\mathbb{P}^1 under the hyperelliptic structure map, we study the real inflection points of the associated complete real linear series \mcD|\mc{D}| on XX. To do so we use Viro's patchworking of real plane curves, recast in the context of some Berkovich spaces studied by M. Jonsson. Our method gives a simpler and more explicit alternative to limit linear series on metrized complexes of curves, as developed by O. Amini and M. Baker, for curves embedded in toric surfaces.

Keywords

Cite

@article{arxiv.1708.08400,
  title  = {Real inflection points of real hyperelliptic curves},
  author = {Indranil Biswas and Ethan Cotterill and Cristhian Garay López},
  journal= {arXiv preprint arXiv:1708.08400},
  year   = {2018}
}

Comments

v.2: improved exposition following the referee's suggestions, and included a new result (Thm 6.1) giving a more refined construction of real inflection on complete series on hyperelliptic curves that includes non-maximal cases. To appear in Transactions of the AMS

R2 v1 2026-06-22T21:25:22.399Z