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Let $p:X \rightarrow S$ be a flat, proper and regular scheme over a strictly henselian discrete valuation ring. We prove that the singularity category of the special fiber with its natural two-periodic structure allows to recover the…

Algebraic Geometry · Mathematics 2024-12-17 Dario Beraldo , Massimo Pippi

We prove extensions of Milnor's theorem for germs with nonisolated singularity and use them to find new classes of genuine real analytic mappings $\psi$ with positive dimensional singular locus $\Sing \psi \subset \psi^{-1}(0)$, for which…

Algebraic Geometry · Mathematics 2017-10-05 Mihai Tibar , Ying Chen , Raimundo N. Araújo dos Santos

For any elliptic K3 surface $\mathfrak{F}: \mathcal{K} \rightarrow \mathbb{P}^1$, we construct a family of collapsing Ricci-flat K\"ahler metrics such that curvatures are uniformly bounded away from singular fibers, and which…

Differential Geometry · Mathematics 2019-10-25 Gao Chen , Jeff Viaclovsky , Ruobing Zhang

We study functions on isolated singularities and prove some results of type Milnor number = Tjurina number. We use them to endow the base space of their miniversal deformation with the structure of F-manifold.

Algebraic Geometry · Mathematics 2007-05-23 Ignacio de Gregorio

We study the boundary L_t of the Milnor fiber for the non-isolated singularities in C^3 with equation z^m - g(x,y) = 0 where g(x,y) is a non-reduced plane curve germ. We give a complete proof that L_t is a Waldhausen graph manifold and we…

Algebraic Geometry · Mathematics 2007-05-23 Francoise Michel , Anne Pichon , Claude Weber

Given a nonconstant polynomial map over the reals having an isolated critical point in the origin and with zero locus of positive dimension, we establish a formula for the singular homology groups of a Milnor fibre relative to its boundary.

Algebraic Geometry · Mathematics 2021-05-11 Lars Andersen

Let (X_R, 0) be a germ of real analytic subset in (R^N, 0) of pure dimension n+1 with an isolated singularity at 0. Let (f_R,0) : (X_R, 0) --> (R,0) a real analytic germ with an isolated singularity at 0, such that its complexification f_C…

Complex Variables · Mathematics 2007-05-23 Daniel Barlet

We construct a (non K\"ahler) compact complex 3-dimensional manifold $X$ having two following properties: 1) for any domain $D$ in $C^2$ every meromorphic map $f$ from this domain into $X$ extends to a meromorphic map from the envelope of…

Complex Variables · Mathematics 2016-09-07 Sergei Ivashkovich

We study the vanishing cycle complex $\varphi_fA_X$ for a holomorphic function $f$ on a reduced complex analytic space $X$ with $A$ a Dedekind domain (for instance, a localization of the ring of integers of a cyclotomic field, where the…

Algebraic Geometry · Mathematics 2020-09-25 Morihiko Saito

We study the topology of the boundaries of the Milnor fibers of real analytics map-germs $f: (\mathbb{R}^M,0) \to (\mathbb{R}^K,0)$ and $f_{I}:=\Pi_{I}\circ f : (\mathbb{R}^M,0) \to (\mathbb{R}^I,0)$ that admit Milnor's tube fibrations,…

Differential Geometry · Mathematics 2023-09-01 R. Araújo dos Santos , A. Menegon , M. Ribeiro , J. Seade , I. D. Santamaria Guarín

The variation operator in singularity theory maps relative homology cycles to compact cycles in the Milnor fiber using the monodromy. We construct its symplectic analogue for an isolated singularity. We define the monodromy Lagrangian Floer…

Symplectic Geometry · Mathematics 2025-10-14 Hanwool Bae , Cheol-Hyun Cho , Dongwook Choa , Wonbo Jeong

On Riemann surfaces $M$, there exists a canonical correspondence between a possibly multivalued function $\Psi_X$ whose differential is single valued ($i.e.$ an additively automorphic singular complex analytic function) and a vector field…

Complex Variables · Mathematics 2024-09-02 Alvaro Alvarez-Parrilla , Jesús Muciño-Raymundo

We consider the varieties of singular $m \times m$ complex matrices which may be either general, symmetric or skew-symmetric (with $m$ even). For these varieties we have shown in another paper that they had compact "model submanifolds", for…

Algebraic Geometry · Mathematics 2018-09-20 James Damon

We consider a real analytic map $F=(f_1,...,f_k) : (\mathbb{R}^n,0) \rightarrow (\mathbb{R}^k,0)$, $2 \le k \le n-1$, that satisfies Milnor's conditions (a) and (b) introduced by D. Massey. This implies that every real analytic…

Algebraic Geometry · Mathematics 2012-11-28 Nicolas Dutertre , Raimundo N. Araújo Dos Santos

Generic relative immersions of compact one-manifolds in the closed unit disk, i.e. divides, provide a powerful combinatorial framework, and allow a topological construction of fibered classical links, for which the monodromy diffeomorphism…

Geometric Topology · Mathematics 2025-03-14 Norbert A'Campo , Pablo Portilla Cuadrado

For isolated complex hypersurface singularities with real defining equation we show the existence of a monodromy vector field such that complex conjugation intertwines the local monodromy diffeomorphism with its inverse. In particular, it…

Algebraic Geometry · Mathematics 2007-05-23 Norbert A'Campo

We study the Milnor monodromies of non-isolated hypersurface singularities and show that the reduced cohomology groups of the Milnor fibers are concentrated in the middle degree for some eigenvalues of the monodromies. As an application of…

Algebraic Geometry · Mathematics 2018-11-22 Takahiro Saito

Let $X$ be a hypersurface with isolated singularities defined by $f$ in ${\bf P^{n+1}}$ with $n>1$. The difference ${\rm def}(X):=h^{n+1}(X)-h^{n-1}(X)$ is called the defect of $X$ (for self-duality of the cohomology of $X$). It is known…

Algebraic Geometry · Mathematics 2026-01-19 Seung-Jo Jung , Morihiko Saito

Let $\{f_t\}$ be a family of complex polynomial functions with line singularities. We show that if $\{f_t\}$ has a uniform stable radius (for the corresponding Milnor fibrations), then the L\^e numbers of the functions $f_t$ are independent…

Algebraic Geometry · Mathematics 2018-03-16 Christophe Eyral

We study Milnor fibers of complexified real line arrangements. We give a new algorithm computing monodromy eigenspaces of the first cohomology. The algorithm is based on the description of minimal CW-complexes homotopic to the complements,…

Algebraic Geometry · Mathematics 2014-05-26 Masahiko Yoshinaga