English

A Caldero-Chapoton map depending on a torsion class

Representation Theory 2016-02-26 v2

Abstract

Frieze patterns of integers were studied by Conway and Coxeter. Let C\mathscr{C} be the cluster category of Dynkin type AnA_n. Indecomposables in C\mathscr{C} correspond to diagonals in an (n+3)(n+3)-gon. Work done by Caldero and Chapoton showed that the Caldero-Chapoton map (which is a map dependent on a fixed object RR of a category, and which goes from the set of objects of that category to Z\mathbb{Z}), when applied to the objects of C\mathscr{C} can recover these friezes. This happens precisely when RR corresponds to a triangulation of the (n+3)(n+3)-gon. Later work by authors such as Bessenrodt, Holm, Jorgensen and Rubey generalised this connection with friezes further, now to dd-angulations of the (n+3)(n+3)-gon with RR basic and rigid. In this paper, we extend these generalisations further still, to the case where the object RR corresponds to a general Ptolemy diagram, i.e. RR is basic and add(R)\textrm{add}(R) is the most general possible torsion class.

Cite

@article{arxiv.1510.07484,
  title  = {A Caldero-Chapoton map depending on a torsion class},
  author = {Thomas A. Fisher},
  journal= {arXiv preprint arXiv:1510.07484},
  year   = {2016}
}

Comments

21 pages, corrected grant reference in acknowledgements

R2 v1 2026-06-22T11:28:56.539Z