Representability of systems of proportionally modular numerical semigroups
arXiv:2607.13619
The authors prove that any system of proportionally modular numerical semigroups can be represented by a canonical equivariant resolution of a weighted homogeneous surface singularity whose link is a rational homology sphere.
Abstract
In this short note we prove that every system of proportionally modular numerical semigroups is representable by a canonical equivariant resolution of a weighted homogeneous surface singularity with rational homology sphere link. The construction starts from the quotient descriptions of proportionally modular numerical semigroups by two-generator numerical semigroups, realizes each quotient by a two-legged canonical equivariant resolution graph, and then glues these graphs with suitable multiplicities.
12 pages