English

Intersections of multicurves from Dynnikov coordinates

Geometric Topology 2017-12-06 v2

Abstract

We present an algorithm for calculating the geometric intersection number of two multicurves on the nn-punctured disk, taking as input their Dynnikov coordinates. The algorithm has complexity O(m2n4)O(m^2n^4), where mm is the sum of the absolute values of the Dynnikov coordinates of the two multicurves. The main ingredient is an algorithm due to Cumplido for relaxing a multicurve.

Keywords

Cite

@article{arxiv.1711.00895,
  title  = {Intersections of multicurves from Dynnikov coordinates},
  author = {S. Öykü Yurttas and Toby Hall},
  journal= {arXiv preprint arXiv:1711.00895},
  year   = {2017}
}

Comments

9 pages. Corrected error in paragraph 1 about complexity of [2] and [9], with thanks to Mark Bell and Saul Schleimer

R2 v1 2026-06-22T22:34:29.177Z