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We study the vanishing cycles of a one-parameter smoothing of a complex analytic space and show that the weight filtration on its perverse cohomology sheaf of the highest degree is quite close to the monodromy filtration so that its graded…

Algebraic Geometry · Mathematics 2010-08-11 Alexandru Dimca , Morihiko Saito

We explicitly describe cohomology of the sheaf of differential forms with poles along a semiample divisor on a complete simplicial toric variety. As an application, we obtain a new vanishing theorem which is an analogue of the…

Algebraic Geometry · Mathematics 2007-05-23 Anvar Mavlyutov

We extend slightly the results of Evens-Mirkovi\'c, and "compute" the characteristic cycles of Intersection Cohomology sheaves on the transversal slices in the double affine Grassmannian and on the hypertoric varieties. We propose a…

Algebraic Geometry · Mathematics 2015-06-15 Michael Finkelberg , Dmitry Kubrak

V.Berkovich, K.Fujiwara and R.Huber have proved independently by different methods that the fiber of the vanishing cycles at a point of the special fiber depends only on the formal completion at this point. We refine this result and prove…

Algebraic Geometry · Mathematics 2007-05-23 Laurent Fargues

Using the vanishing cycles of simple singularities, we study the eigenvectors of Cartan matrices of finite root systems, and of q-deformations of these matrices.

Group Theory · Mathematics 2016-08-19 Laura Brillon , Revaz Ramazashvili , Vadim Schechtman , Alexander Varchenko

We develop a theory of nearby and vanishing cycles in the context of finite-coefficient Zariski-constructible sheaves over a non-archimedean field which is non-trivially valued, complete, algebraically closed, and of mixed characteristic or…

Algebraic Geometry · Mathematics 2025-04-24 Tong Zhou

This is an expository paper on Garland's vanishing theorem specialized to the case when the linear algebraic group is $\mathrm{SL}_n$. Garland's theorem can be stated as a vanishing of the cohomology groups of certain finite simplicial…

Combinatorics · Mathematics 2016-12-26 Mihran Papikian

We formulate certain sufficient conditions for the symplectic monodromy of an isolated quasihomogeneous singularity to be of infinite order in the relative symplectic mapping class group of the Milnor fibre and give a proof using Maslov…

Differential Geometry · Mathematics 2014-04-29 Andreas Klein

The middle homology of the Milnor fiber of a quasihomogeneous polynomial with an isolated singularity is a ${\mathbb Z}$-lattice and comes equipped with an automorphism of finite order, the integral monodromy. Orlik (1972) made a precise…

Algebraic Topology · Mathematics 2020-09-17 Claus Hertling , Makiko Mase

We study the topology of a line singularity, which is a complex hypersurface with non-isolated singularity given by a complex line. We describe the degeneration of its Milnor fibre to the singular hypersurface by means of a pair of…

Complex Variables · Mathematics 2014-12-01 Aurélio Menegon Neto

For a local system and a function on a smooth complex algebraic variety, we give a proof of a conjecture of M. Kontsevich on a formula for the vanishing cycles using the twisted de Rham complex of the formal microlocalization of the…

Algebraic Geometry · Mathematics 2013-09-03 Claude Sabbah , Morihiko Saito

Suppose that $f$ defines a singular, complex affine hypersurface. If the critical locus of $f$ is one-dimensional, we obtain new general bounds on the ranks of the homology groups of the Milnor fiber of $f$. This result has an interesting…

Algebraic Geometry · Mathematics 2007-05-23 Lê Dũng Tráng , David B. Massey

The main result of this paper is a proof using real analysis of the monotonicity of the topological entropy for the family of quadratic maps, sometimes called Milnor's Monotonicity Conjecture. In contrast, the existing proofs rely in one…

Dynamical Systems · Mathematics 2020-10-13 José M. Amigó , Angel Giménez

We reprove and generalize the result that the intersection cohomology groups of a toric variety with coefficient in a nontrivial rank one local system vanish. We prove a similar vanishing result for a certain class of varieties on which a…

Algebraic Geometry · Mathematics 2024-03-13 Yiyu Wang

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

We resume the study initiated in \cite{CL}. For a generic curve $C$ in an ample linear system $\vert \mathcal{L} \vert$ on a toric surface $X$, a vanishing cycle of $C$ is an isotopy class of simple closed curve that can be contracted to a…

Geometric Topology · Mathematics 2019-05-21 Rémi Crétois , Lionel Lang

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

As is remarked by B. Totaro, R. Thomas essentially proved that the Hodge conjecture is inductively equivalent to the existence of a hyperplane section, called a generalized Thomas hyperplane section, such that the restriction to it of a…

Algebraic Geometry · Mathematics 2008-09-29 Morihiko Saito

Using the work of Dwyer, Weiss, and Williams we associate an invariant to any topologically trivial family of smooth h-cobordisms. This invariant is called the smooth structure class, and is closely related to the higher Franz--Reidemeister…

Geometric Topology · Mathematics 2021-11-08 Yajit Jain

The main result of the paper is a classification of singularities of complex skew-symmetric matrix families of even size which are simple under a natural equivalence relation. The classification is obtained by appropriate suspensions of…

Algebraic Geometry · Mathematics 2022-09-13 J. W. Bruce , V. V. Goryunov , G. J. Haslinger