English

Positivity for cluster algebras from surfaces

Combinatorics 2009-06-04 v1 Representation Theory

Abstract

We give combinatorial formulas for the Laurent expansion of any cluster variable in any cluster algebra coming from a triangulated surface (with or without punctures), with respect to an arbitrary seed. Moreover, we work in the generality of principal coefficients. An immediate corollary of our formulas is a proof of the positivity conjecture of Fomin and Zelevinsky for cluster algebras from surfaces, in geometric type.

Keywords

Cite

@article{arxiv.0906.0748,
  title  = {Positivity for cluster algebras from surfaces},
  author = {Gregg Musiker and Ralf Schiffler and Lauren Williams},
  journal= {arXiv preprint arXiv:0906.0748},
  year   = {2009}
}

Comments

67 pages, 45 figures, comments welcome

R2 v1 2026-06-21T13:09:19.051Z