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Related papers: A note on distinguished bases of singularities

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We give a survey on some aspects of the topological investigation of isolated singularities of complex hypersurfaces by means of Picard-Lefschetz theory. We focus on the concept of distinguished bases of vanishing cycles and the concept of…

Algebraic Geometry · Mathematics 2019-05-30 Wolfgang Ebeling

Isolated hypersurface singularities come equipped with a Milnor lattice, a ${\mathbb Z}$-lattice of finite rank, and a set of $distinguished$ ${\mathbb Z}$-bases of this lattice. Usually these bases are constructed from $one$ morsification…

Algebraic Geometry · Mathematics 2018-06-05 Claus Hertling , Céline Roucairol

We prove an extended Lefschetz principle for a large class of pencils of hypersurfaces having isolated singularities, possibly in the axis, and show that the module of vanishing cycles is generated by the images of certain variation maps.

Algebraic Geometry · Mathematics 2007-05-23 Mihai Tibar

Using iterated vanishing cycles and convolution, we prove a motivic version of a conjecture of Steenbrink concerning the spectrum of hypersurface singularities

Algebraic Geometry · Mathematics 2007-12-05 G. Guibert , F. Loeser , M. Merle

Isolated hypersurface singularities come equipped with distinguished bases of their Milnor lattices and with upper triangular integral matrices, which are called here distinguished matrices. These matrices form an orbit of a braid group and…

Algebraic Geometry · Mathematics 2026-03-03 Sven Balnojan , Claus Hertling

This is the abstract prepared for Workshop on Topology and Geometry (Zhang jiang, China, October 1994), and is a review of my recent works. What kinds of combinations of singularities can appear in small deformation fibers of a fixed…

alg-geom · Mathematics 2008-02-03 Tohsuke Urabe

In this paper we discuss an obstruction to the integral Hodge conjecture, which arises from certain behavior of vanishing cycles. This allows us to construct new counter-examples to the integral Hodge conjecture. One typical such…

Algebraic Geometry · Mathematics 2019-01-23 Mingmin Shen

All varieties, extremal contractions, singularities are divided on exceptional and non-exceptional ones. Roughly speaking, there are the infinite families of non-exceptional varieties, extremal contractions or singularities and only the…

Algebraic Geometry · Mathematics 2015-06-26 S. A. Kudryavtsev

We consider links of complex isolated hypersurface singularities in $\mathbb{C}^{n+1}$ and study differentiable maps defined by restricting holomorphic functions to the links. We give an explicit example in which such a restriction gives a…

Geometric Topology · Mathematics 2024-02-06 Osamu Saeki , Shuntaro Sakurai

A log symplectic manifold is a complex manifold equipped with a complex symplectic form that has simple poles on a hypersurface. The possible singularities of such a hypersurface are heavily constrained. We introduce the notion of an…

Algebraic Geometry · Mathematics 2019-02-20 Brent Pym

In this series of lectures, I will discuss results for complex hypersurfaces with non-isolated singularities. In Lecture 1, I will review basic definitions and results on complex hypersurfaces, and then present classical material on the…

Algebraic Geometry · Mathematics 2015-11-16 David B. Massey

We employ the perverse vanishing cycles to show that each reduced cohomology group of the Milnor fiber, except the top two, can be computed from the restriction of the vanishing cycle complex to only singular strata with a certain lower…

Algebraic Geometry · Mathematics 2022-07-08 Laurenţiu Maxim , Laurenţiu Păunescu , Mihai Tibăr

Locally analytically, any isolated double point occurs as a double covering of a smooth surface. It can be desingularized via the canonical resolution, as it is well-known. In this paper we explicitly compute the fundamental cycle of both…

Algebraic Geometry · Mathematics 2007-05-23 Alberto Calabri , Rita Ferraro

We extend the results from the previous paper by A. Fr\"uhbis-Kr\"uger and the author [arXiv:1501.01915] to the vanishing topology of those singularities in the title. Studying the case of possibly non-isolated singularities in the Tjurina-…

Algebraic Geometry · Mathematics 2021-09-15 Matthias Zach

We construct examples of flat surfaces in $\mathbb{H}^3$ which are graphs over a two-punctured horosphere and classify complete embedded flat surfaces in $\mathbb{H}^3$ with only one end and at most two isolated singularities.

Differential Geometry · Mathematics 2009-05-15 Armando V. Corro , Antonio Martinez , Francisco Milan

We consider compact hyperbolic Coxeter polytopes whose Coxeter diagram contains a unique dotted edge. We prove that such a polytope in d-dimensional hyperbolic space has at most d+3 facets. In view of results of Lann\'er, Kaplinskaja,…

Metric Geometry · Mathematics 2022-09-13 Anna Felikson , Pavel Tumarkin

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 compute the mapping class group-valued monodromy of any sufficiently ample linear system on any smooth simply connected projective surface, identifying this with the r-spin mapping class group associated to a maximal root of the adjoint…

Algebraic Geometry · Mathematics 2025-12-04 Ishan Banerjee , Nick Salter

Using the path lattice cohomology we provide a conceptual topological characterization of the geometric genus for certain complex normal surface singularities with rational homology sphere links, which is uniformly valid for all…

Algebraic Geometry · Mathematics 2016-03-27 András Némethi , Baldur Sigurðsson

We study the systems of ordinary differential equations which are implicit with respect to the higher derivatives, appearing in the linear form, and their solutions near the singular points. The invertibility of the higher derivatives…

Mathematical Physics · Physics 2007-05-23 M. V. Pomazanov
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