English

Thom condition and Monodromy

Algebraic Geometry 2024-03-25 v2 Algebraic Topology

Abstract

We give the definition of the Thom condition and we show that given any germ of complex analytic function f:(X,x)(C,0)f:(X,x)\to(\mathbb{C},0) on a complex analytic space XX, there exists a geometric local monodromy without fixed points, provided that fmX,x2f\in\mathfrak m_{X,x}^2, where mX,x\mathfrak m_{X,x} is the maximal ideal of OX,x\mathcal O_{X,x}. This result generalizes a well-known theorem of the second named author when XX is smooth and proves a statement by Tibar in his PhD thesis. It also implies the A'Campo theorem that the Lefschetz number of the monodromy is equal to zero. Moreover, we give an application to the case that XX has maximal rectified homotopical depth at xx and show that a family of such functions with isolated critical points and constant total Milnor number has no coalescing of singularities.

Keywords

Cite

@article{arxiv.2104.05385,
  title  = {Thom condition and Monodromy},
  author = {R. Giménez Conejero and Lê Dũng Tráng and J. J. Nuño-Ballesteros},
  journal= {arXiv preprint arXiv:2104.05385},
  year   = {2024}
}

Comments

25 pages, 6 figures

R2 v1 2026-06-24T01:04:32.394Z