English

Zariski's multiplicity conjecture for quasihomogeneous hypersurfaces with non-isolated singularities

Algebraic Geometry 2025-11-11 v3 Complex Variables

Abstract

In this work, we consider a pair (X,0)(\textbf{X},0) and (Y,0)(\textbf{Y},0) of hypersurfaces in (Cn+1,0)(\mathbb{C}^{n+1},0) parametrized by finitely determined, quasihomogeneous map germs ff and g,g, respectively. Zariski asked whether the multiplicity is preserved under topological equivalence of hypersurface germs. We address this question within a wide class of nn-dimensional quasihomogeneous varieties with non-isolated singularities in Cn+1,\mathbb{C}^{n+1}, where 2n4.2\le n\le 4. This class consists of varieties that arise as image of finitely determined, quasihomogeneous map germs. Using a quasihomogeneous normal form, we derive explicit formulas for the multiplicity in terms of the weights and the degrees of the map germ. Our results show that multiplicity, within this setting, is determined by the weighted data and is invariant under topological equivalence, thereby confirming Zariski's multiplicity conjecture and extending current knowledge beyond the isolated singularity case.

Keywords

Cite

@article{arxiv.2309.02624,
  title  = {Zariski's multiplicity conjecture for quasihomogeneous hypersurfaces with non-isolated singularities},
  author = {Otoniel Nogueira da Silva and Manoel Messias da Silva Júnior},
  journal= {arXiv preprint arXiv:2309.02624},
  year   = {2025}
}