2 papers
math.CO2023
The Jacobian of a Sixth-Root-of-Unity Matroid
Matthew Baker, Changxin Ding, Xu Zhuang
The Jacobian group (also called the sandpile group, Picard group, or critical group) of a graph or, more generally, of a regular matroid has been well studied. Sixth-root-of-unity…
math.CO2021
The rotor-routing torsor and the Bernardi torsor disagree for every non-planar ribbon graph
Changxin Ding
Let be a ribbon graph. Matthew Baker and Yao Wang proved that the rotor-routing torsor and the Bernardi torsor for , which are two torsor structures on the set of spanning t…