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Related papers: A remark on vanishing cycles with two strata

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The method of intersection spaces associates rational Poincar\'e complexes to singular stratified spaces. For a conifold transition, the resulting cohomology theory yields the correct count of all present massless 3-branes in type IIB…

Algebraic Geometry · Mathematics 2016-05-24 Markus Banagl , Nero Budur , Laurentiu Maxim

Let $f\colon X\to\mathbb{A}^1_k$ be a morphism from a smooth variety to an affine line with an isolated singular point. For such a singularity, we have two invariants. One is a non-degenerate symmetric bilinear form (de Rham), and the other…

Algebraic Geometry · Mathematics 2026-04-06 Daichi Takeuchi

We employ the formalism of vanishing cycles and perverse sheaves to introduce and study the vanishing cohomology of complex projective hypersurfaces. As a consequence, we give upper bounds for the Betti numbers of projective hypersurfaces,…

Algebraic Geometry · Mathematics 2022-09-15 Laurenţiu Maxim , Laurenţiu Păunescu , Mihai Tibăr

We describe the relationship between intersection cohomology with twisted coefficients and the perverse sheaves which play the role of the eigenspaces for the Milnor monodromy of an affine hypersurface.

Algebraic Geometry · Mathematics 2019-02-04 David B. Massey

Let f be a hypersurface surface local singularity whose zero set has 1-dimensional singular locus. We develop an explicit procedure that provides the boundary of the Milnor fibre of f as an oriented plumbed 3-manifold. The method provides…

Algebraic Geometry · Mathematics 2011-06-23 Andras Nemethi , Agnes Szilard

We investigate deformations of functions on affine space, deformations in which the changes specialize to a distinguished point in the zero-locus of the original function. Such deformations enable us to obtain nice results on the cohomology…

Algebraic Geometry · Mathematics 2016-06-23 David B. Massey

Let $\Cal U$ be an open neighborhood of the origin in $\Bbb C^{n+1}$ and let $f:(\Cal U, \bold 0)\to(\Bbb C, 0)$ be complex analytic. Let $z_0$ be a generic linear form on $\Bbb C^{n+1}$. If the relative polar curve $\Gamma^1_{f, z_0}$ at…

Algebraic Geometry · Mathematics 2007-05-23 David B. Massey

In the first half of the paper, we translate in the geometric situation of Drinfeld varieties, the principal results of the Harris and Taylor's book. We give in particular the restriction to the open strata of the vanishing cycles sheaves…

Algebraic Geometry · Mathematics 2018-09-03 Pascal Boyer

We are going to use the Euler's vector fields in order to show that for real quasi-homogeneous singularities with isolated critical value, the Milnor's fibration in a "thin" hollowed tube involving the zero level and the fibration in the…

Geometric Topology · Mathematics 2016-05-09 R. Araujo dos Santos

Consider an analytical function $f:V\subset\mathbb R^2\rightarrow\mathbb R$ having $0$ as its regular value, a switching manifold $\Sigma=f^{-1}(0)$ and a piecewise analytical vector field $X=(X^+,X^-)$, i.e. $X^\pm$ are analytical vector…

Dynamical Systems · Mathematics 2023-02-21 Claudio Buzzi , João Carlos Medrado , Claudio Pessoa

In this note, we provide a quick introduction to the study of the Milnor fibration via the derived category and perverse sheaves. This is primarily a dictionary for translating from the standard topological setting to the derived category…

Algebraic Geometry · Mathematics 2012-07-31 David B. Massey

We define and study a relative perverse $t$-structure associated with any finitely presented morphism of schemes $f: X\to S$, with relative perversity equivalent to perversity of the restrictions to all geometric fibres of $f$. The…

Algebraic Geometry · Mathematics 2023-05-11 David Hansen , Peter Scholze

This is a mostly expository paper, intended to explain a very natural relationship between two a priori distinct notions appearing in the literature: Generic Vanishing in the context of vanishing theorems and birational geometry, and…

Algebraic Geometry · Mathematics 2009-11-23 Mihnea Popa

This text is a study of the missing case in our article [B.91], that is to say the eigenvalue 1 case. Of course this is a more involved situation because the existence of the smooth stratum for the hypersurface {f = 0} forces to consider…

Algebraic Geometry · Mathematics 2007-05-23 D. Barlet

We extend the circle of ideas from a previous paper on hypersurfaces to functions $f \colon (\mathbb C^n, 0) \to (\mathbb C^k, 0)$ with an isolated singularity in a stratified sense on an arbitrary, but fixed complex analytic germ $(X, 0)$.…

Algebraic Geometry · Mathematics 2024-11-06 Matthias Zach

The goal of this paper is to propose a theory of mirror symmetry for varieties of general type. Using Landau-Ginzburg mirrors as motivation, we describe the mirror of a hypersurface of general type (and more generally varieties of…

Algebraic Geometry · Mathematics 2016-04-08 Mark Gross , Ludmil Katzarkov , Helge Ruddat

For a holomorphic function on a complex manifold, we show that the vanishing cohomology of lower degree at a point is determined by that for the points near it, using the perversity of the vanishing cycle complex. We calculate it explicitly…

Algebraic Geometry · Mathematics 2007-05-23 Alexandru Dimca , Morihiko Saito

We describe a generalization of Milnor's formula for the Milnor number of an isolated hypersurface singularity to the case of a function $f$ whose restriction $f|(X,0)$ to an arbitrarily singular reduced complex analytic space $(X,0)…

Algebraic Geometry · Mathematics 2020-02-11 Matthias Zach

While the topological types of {normal} surface singularities with homology sphere link have been classified, forming a rich class, until recently little was known about the possible analytic structures. We proved in [Geom. Topol. 9(2005)…

Algebraic Geometry · Mathematics 2014-11-11 Walter D. Neumann , Jonathan Wahl

We develop recursive formulas for the horizontal and vertical monodromies of a quasi-ordinary surface. These are monodromies associated to the Milnor fiber of a slice transverse to a component of the singular locus. In the course of working…

Algebraic Geometry · Mathematics 2009-02-17 Gary Kennedy , Lee J. McEwan