English

Laminations of punctured surfaces as $\tau$-regular irreducible components

Representation Theory 2025-09-18 v3

Abstract

Let Σ:=(Σ,M,P)\boldsymbol{\Sigma}:=(\Sigma,\mathbb{M},\mathbb{P}) be a surface with marked points MΣ\mathbb{M}\subset\partial\Sigma\neq\varnothing on the boundary, and punctures PΣΣ\mathbb{P}\subset\Sigma\setminus\partial\Sigma, and TT an arbitrary tagged triangulation of Σ\boldsymbol{\Sigma} in the sense of Fomin-Shapiro-Thurston. The Jacobian algebra A(T):=P(Q(T),W(T))A(T):=\mathcal{P}(Q(T), W(T)) corresponding to the non-degenerate potential W(T)W(T) defined by Cerulli Irelli and the second author is tame, as shown by Schr\"{o}er and the first two authors. In this paper, we show that there is a natural isomorphism πT:Lam(Σ)DecIrrτ(A(T))\pi_T:\operatorname{Lam}(\boldsymbol{\Sigma})\rightarrow\operatorname{DecIrr}^\tau(A(T)) of tame partial KRS-monoids that intertwines dual shear coordinates with respect to TT, and generic gg-vectors of irreducible components. Here, Lam(Σ)\operatorname{Lam}(\boldsymbol{\Sigma}) is the set of laminations of Σ\boldsymbol{\Sigma} considered by Musiker-Schiffler-Williams, with the disjoint union of non-intersecting laminations as partial monoid operation. On the other hand, DecIrrτ(A(T))\operatorname{DecIrr}^\tau(A(T)) denotes the set of generically τ\tau-regular irreducible components of the decorated representation varieties of A(T)A(T), with the direct sum of generically EE-orthogonal irreducible components as partial monoid operation, where EE is the symmetrized EE-invariant of Derksen-Weyman-Zelevinsky, E(,)=dimHomA(T)(,τ())+dimHomA(T)(,τ())E(-,\bullet)=\dim\operatorname{Hom}_{A(T)}(-,\tau(\bullet))+\dim\operatorname{Hom}_{A(T)}(\bullet,\tau(-)).

Keywords

Cite

@article{arxiv.2308.00792,
  title  = {Laminations of punctured surfaces as $\tau$-regular irreducible components},
  author = {Christof Geiß and Daniel Labardini-Fragoso and Jon Wilson},
  journal= {arXiv preprint arXiv:2308.00792},
  year   = {2025}
}

Comments

v2: Main result vastly generalized, from tagged triangulations of signature zero, to arbitrary tagged triangulations; v3: Changed terminology from "$\tau$-reduced" to "$\tau$-regular", including the title. After referee report many corrections, more examples, added indices for notation and symbols. 46 pages, 13 figures. To appear in IMRN