Cluster exchange groupoids and framed quadratic differentials

• 成果类型: Article
• 署名作者: King, Alastair; Qiu, Yu
• 署名单位: University of Bath; Tsinghua University
• 刊物名称: INVENTIONES MATHEMATICAE
• ISSN/ISSBN: 0020-9910
• DOI: 10.1007/s00222-019-00932-y
• 发表日期: 2020
• 页码: 479-523
• 关键词: braid group; connected components; stability conditions; ALGEBRAS; CATEGORIES; QUIVERS; SURFACES; potentials; Mutation; SPACES

摘要

We introduce the cluster exchange groupoid associated to a non-degenerate quiver with potential, as an enhancement of the cluster exchange graph. In the case that arises from an (unpunctured) marked surface, where the exchange graph is modelled on the graph of triangulations of the marked surface, we show that the universal cover of this groupoid can be constructed using the covering graph of triangulations of the surface with extra decorations. This covering graph is a skeleton for a space of suitably framed quadratic differentials on the surface, which in turn models the space of Bridgeland stability conditions for the 3-Calabi-Yau category associated to the marked surface. By showing that the relations in the covering groupoid are homotopically trivial when interpreted as loops in the space of stability conditions, we show that this space is simply connected.