English

Combinatorial Approaches to Exceptional Sequences for Weighted Projective Lines of Type $(p,q)$

Representation Theory 2025-08-27 v1 Combinatorics

Abstract

We provide a combinatorial description of morphisms in the coherent sheaf category coh\mboxX(p,q){\rm coh}\mbox{-}\mathbb{X}(p,q) over weighted projective line of type (p,q)(p,q) via a marked annulus. This leads to a geometric realization of exceptional sequences in coh\mboxX(p,q){\rm coh}\mbox{-}\mathbb{X}(p,q). As applications, we present a classification of complete exceptional sequences, an effective method for enlarging exceptional sequences, and a new proof of the transitivity of the braid group action on complete exceptional sequences. Besides, we offer a combinatorial description of tilting bundles via lattice paths and count the number of tilting sheaves in coh\mboxX(p,q){\rm coh}\mbox{-}\mathbb{X}(p,q), up to the Auslander-Reiten translation.

Keywords

Cite

@article{arxiv.2508.18618,
  title  = {Combinatorial Approaches to Exceptional Sequences for Weighted Projective Lines of Type $(p,q)$},
  author = {Jianmin Chen and Yiting Zheng},
  journal= {arXiv preprint arXiv:2508.18618},
  year   = {2025}
}