PreprintarXiv licencearXiv
Minimal transitive factorizations supported on quasi-threshold graphs
Abstract
We study the number of minimal transitive factorizations of the identity permutation in Sn into transpositions supported on a quasi-threshold graph. We show that this number is always divisible by $(2n-2)!/n!$, which is the factorization count for a star graph, as shown by Irving and Rattan. To prove this, we give a combinatorial formula for the number of such factorizations as a weighted sum over a subset of the nn−2 factorization trees, which are edge-weighted spanning trees satisfying certain flow constraints.
Related
- Counting Minimal Vertex Cutsets and a Gap at 1 for Site Percolation on Vertex-Transitive Graphs
- Multi-Way Expansion, Laplacian Gaps, and Imprimitivity in Vertex-Transitive Graphs
- Vertex-transitive strongly regular graphs in the switching class of doubly transitive two-graphs
- Enumeration of small vertex-transitive directed strongly regular graphs
- On Edge-Primitive $2$-Arc-Transitive (Bi-)Cayley Graphs
BibTeX
@misc{li2026minimal,
title = {{Minimal transitive factorizations supported on quasi-threshold graphs}},
author = {Cordelia Yuqiao Li and Ricky Ini Liu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.31982},
eprint = {2609.31982},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.31982},
}
RIS
TY - UNPB
TI - Minimal transitive factorizations supported on quasi-threshold graphs
AU - Cordelia Yuqiao Li
AU - Ricky Ini Liu
PY - 2026
DA - 2026/09/25
PB - arXiv
DO - 10.48550/arxiv.2609.31982
UR - https://arxiv.org/abs/2609.31982
AB - We study the number of minimal transitive factorizations of the identity permutation in S_n into transpositions supported on a quasi-threshold graph. We show that this number is always divisible by $(2n-2)!/n!$, which is the factorization count for a star graph, as shown by Irving and Rattan. To prove this, we give a combinatorial formula for the number of such factorizations as a weighted sum over a subset of the n^n−2 factorization trees, which are edge-weighted spanning trees satisfying certain flow constraints.
ER -