English

A note on tropical triangles in the plane

Combinatorics 2008-10-16 v3

Abstract

We define transversal tropical triangles (affine and projective) and characterize them via six inequalities to be satisfied by the coordinates of the vertices. We prove that the vertices of a transversal tropical triangle are tropically independent and they tropically span a classical hexagon whose sides have slopes ,0,1\infty,0,1. Using this classical hexagon, we determine a parameter space for transversal tropical triangles. The coordinates of the vertices of a transversal tropical triangle determine a tropically regular matrix. Triangulations of the tropical plane are obtained.

Keywords

Cite

@article{arxiv.math/0701222,
  title  = {A note on tropical triangles in the plane},
  author = {M. Ansola and M. J. de la Puente},
  journal= {arXiv preprint arXiv:math/0701222},
  year   = {2008}
}

Comments

15 pages, 2 figures. The paper has been fully revised and enlarged. Tropical triangles called transversal here, were called proper and stable in a previous version. To appear in Acta Math. Sinica (English series)