Homogeneous Khovanskii bases and MUVAK bases
Johannes Schmitt
TL;DR
This work extends the theory of Khovanskii bases by introducing Δ-homogeneous Khovanskii bases and their multi-valuation generalization, MUVAK bases, and provides algorithms for computing them. It establishes a robust framework connecting valuations, graded structures, and initial forms, and demonstrates termination under suitable finite-dimensional conditions. The authors apply these concepts to Cox rings of minimal models for quotient singularities, showing how Ab(G)^∨-homogeneous MUVAK bases generate the Cox ring, and compare their multi-valuation method favorably against Yamagishi's algorithm. Overall, the paper advances algorithmic tools for a broad class of graded algebras and their geometric applications, including explicit computations of Cox rings.
Abstract
In 2019, Kaveh and Manon introduced Khovanskii bases as a special 'Gröbner-like' generating system of an algebra. We extend their work by considering an arbitrary grading on the algebra and propose a definition for a 'homogeneous Khovanskii basis' that respects this grading. We generalize Khovanskii bases further by taking multiple valuations into account (MUVAK bases). We give algorithms in both cases. MUVAK bases appear in the computation of the Cox ring of a minimal model of a quotient singularity. Our algorithm is an improvement of an algorithm by Yamagishi in this situation.
