English

Transverse slices, Ruas' conjecture, and Zariski's multiplicity conjecture for quasihomogeneous surfaces

Algebraic Geometry 2025-10-14 v2 Complex Variables

Abstract

In this work, we consider a finitely determined, quasihomogeneous, corank 1 map germ ff from (C2,0)(\mathbb{C}^2,0) to (C3,0)(\mathbb{C}^3,0). We introduce the concept of the μm,k\mu_{\mathbf{m},\mathbf{k}}-minimal transverse slice of ff}. Since such a slice is a plane curve, it admits a topological normal form, which we describe explicitly. Assuming the μm,k\mu_{\mathbf{m},\mathbf{k}}-minimal transverse slice hypothesis, we provide a proof for the equivalence between topological triviality and Whitney equisingularity in Ruas' conjecture within this setting. We also provide a counterexample which shows that Whitney equingularity does not imply bi-Lipschitz equisingularity, given an answer to a question by Ruas. Moreover, we show that every topologically trivial 11-parameter unfolding of f=(f1,f2,f3)f=(f_1,f_2,f_3) (not necessarily with μm,k\mu_{\mathbf{m},\mathbf{k}}-minimal transverse slice) is of non-negative degree; that is, any additional term α\alpha in the deformation of fif_i has weighted degree not smaller than that of fif_i. As a consequence, we provide a proof of Zariski's multiplicity conjecture for 1-parameter families of such germs.

Keywords

Cite

@article{arxiv.2509.01634,
  title  = {Transverse slices, Ruas' conjecture, and Zariski's multiplicity conjecture for quasihomogeneous surfaces},
  author = {Otoniel Nogueira da Silva and Manoel Messias da Silva Júnior},
  journal= {arXiv preprint arXiv:2509.01634},
  year   = {2025}
}