English

Lipschitz geometry of complex surface germs via inner rates of primary ideals

Algebraic Geometry 2025-03-06 v2 Complex Variables

Abstract

Let (X,0)(X, 0) be a normal complex surface germ embedded in (Cn,0)(\mathbb{C}^n, 0), and denote by m\mathfrak{m} the maximal ideal of the local ring OX,0\mathcal{O}_{X,0}. In this paper, we associate to each m\mathfrak{m}-primary ideal II of OX,0\mathcal{O}_{X,0} a continuous function II\mathcal{I}_I defined on the set of positive (suitably normalized) semivaluations of OX,0\mathcal{O}_{X,0}. We prove that the function Im\mathcal{I}_{\mathfrak{m}} is determined by the outer Lipschitz geometry of the surface (X,0)(X, 0). We further demonstrate that for each m\mathfrak{m}-primary ideal II, there exists a complex surface germ (XI,0)(X_I, 0) with an isolated singularity whose normalization is isomorphic to (X,0)(X, 0) and II=ImI\mathcal{I}_I = \mathcal{I}_{\mathfrak{m}_I}, where mI\mathfrak{m}_I is the maximal ideal of OXI,0\mathcal{O}_{X_I,0}. Subsequently, we construct an infinite family of complex surface germs with isolated singularities, whose normalizations are isomorphic to (X,0)(X,0) (in particular, they are homeomorphic to (X,0)(X,0)) but have distinct outer Lipschitz types.

Keywords

Cite

@article{arxiv.2407.14265,
  title  = {Lipschitz geometry of complex surface germs via inner rates of primary ideals},
  author = {Yenni Cherik},
  journal= {arXiv preprint arXiv:2407.14265},
  year   = {2025}
}