Varieties of chain complexes and mixed dimer covers
Abstract
A quiver representation consists of a collection of vector spaces along with a set of arrows, which are linear maps between these spaces. In this work, we study quiver representations in equioriented type A which are also chain complexes; that is, in which consecutive arrows compose to zero. We show that orbits of these representations under a change of basis action are in bijection with mixed dimer covers of a 2 × n grid graph. The latter object can be endowed with a partial order which is a distributive lattice, and we show that the degeneration order on the orbits of chain complexes is a coarsening of this partial order. In addition, we use recent matrix formulae of Claussen and Ovenhouse to enumerate these orbits. This also computes the Kostant partition function applied to height-restricted, type A roots. When the dimension vector is uniform, we discuss a correspondence with paths of a beam of light bouncing between glass plates and give an explicit generating function.
Related
BibTeX
@misc{anderson2026varieties,
title = {{Varieties of chain complexes and mixed dimer covers}},
author = {Portia X. Anderson and Esther Banaian and Melanie J. Ferreri and Nicholas Mayers and Shiyun Wang and Alexander N. Wilson},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.00202},
eprint = {2609.00202},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.00202},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Varieties of chain complexes and mixed dimer covers
AU - Portia X. Anderson
AU - Esther Banaian
AU - Melanie J. Ferreri
AU - Nicholas Mayers
AU - Shiyun Wang
AU - Alexander N. Wilson
PY - 2026
DA - 2026/09/01
PB - arXiv
DO - 10.48550/arxiv.2609.00202
UR - https://arxiv.org/abs/2609.00202
AB - A quiver representation consists of a collection of vector spaces along with a set of arrows, which are linear maps between these spaces. In this work, we study quiver representations in equioriented type A which are also chain complexes; that is, in which consecutive arrows compose to zero. We show that orbits of these representations under a change of basis action are in bijection with mixed dimer covers of a 2 × n grid graph. The latter object can be endowed with a partial order which is a distributive lattice, and we show that the degeneration order on the orbits of chain complexes is a coarsening of this partial order. In addition, we use recent matrix formulae of Claussen and Ovenhouse to enumerate these orbits. This also computes the Kostant partition function applied to height-restricted, type A roots. When the dimension vector is uniform, we discuss a correspondence with paths of a beam of light bouncing between glass plates and give an explicit generating function.
ER -