English

A cluster expansion formula ($A_n$ case)

Representation Theory 2007-05-23 v2 Rings and Algebras

Abstract

We consider the Ptolemy cluster algebras, which are cluster algebras of finite type AA (with non-trivial coefficients) that have been described by Fomin and Zelevinsky using triangulations of a regular polygon. Given any seed \zS\zS in a Ptolemy cluster algebra, we present a formula for the expansion of an arbitrary cluster variable in terms of the cluster variables of the seed \zS\zS. Our formula is given in a combinatorial way, using paths on a triangulation of the polygon that corresponds to the seed \zS\zS.

Keywords

Cite

@article{arxiv.math/0611956,
  title  = {A cluster expansion formula ($A_n$ case)},
  author = {Ralf Schiffler},
  journal= {arXiv preprint arXiv:math/0611956},
  year   = {2007}
}

Comments

9 pages, 2 figures; Version 2: condition (T6) added in Definition 1, Section 2 rewritten, references added