Algorithmic aspects of semistability of quiver representations

We study the semistability of quiver representations from an algorithmic perspective. We present efficient algorithms for several fundamental computational problems on the semistability of quiver representations: deciding semistability and σ-semistability, finding maximizers of King's criterion, and finding the Harder-Narasimhan filtration. We also investigate a class of polyhedral cones defined by the linear system in King's criterion, which we call King cones. We demonstrate that the King cones for rank-one representations can be encoded by submodular flow polytopes, allowing us to decide the σ-semistability of rank-one representations in strongly polynomial time. Our argument employs submodularity in quiver representations, which may be of independent interest.