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We define a partition of ${\overline{M}_g^n}$ and show that the cohomology of ${\overline{M}_g^n}$ in a given degree admits a filtration whose respective quotients are isomorphic to the shifted cohomology groups of the parts if $g$ is…

alg-geom · Mathematics 2008-02-03 Martin Pikaart

We describe explicitely the unique isomorphism $\mathrm{H}_{sin}^*(X,\underline{\mathbb{Z}})\xrightarrow{\sim} \check{\mathrm{H}}_{\mathcal{U}}^*(X,\underline{\mathbb{Z}})$ between the cohomologies computed with the singular and \v{C}ech…

Algebraic Topology · Mathematics 2025-12-02 Marco Belli

Over an arbitrary compact complex space or an arbitrary germ of complex space $X$, we provide fine resolutions of pure Hodge modules with strict supports $IC_X(\mathbb{V})$ via differential forms with locally $L^2$ boundary conditions. When…

Algebraic Geometry · Mathematics 2021-03-09 Junchao Shentu , Chen Zhao

We will prove the relative homotopy principle for smooth maps with singularities of a given {\cal K}-invariant class with a mild condition. We next study a filtration of the group of homotopy self-equivalences of a given manifold P by…

Geometric Topology · Mathematics 2007-05-23 Yoshifumi Ando

Classical Hodge theory endows the square integrable cohomology of a Shimura variety X with values in a locally homogeneous polarized variation of Hodge structure E with a natural Hodge decomposition. The theory of Morihiko Saito does the…

Algebraic Geometry · Mathematics 2026-05-26 Eduard Looijenga

We begin the systematic study of cohomological Hecke operators of modifications of coherent sheaves on a smooth surface $X$, along a fixed proper curve $Z \subset X$. We develop the necessary geometric foundations in order to define the…

Algebraic Geometry · Mathematics 2026-03-03 Duiliu-Emanuel Diaconescu , Mauro Porta , Francesco Sala , Olivier Schiffmann , Eric Vasserot

A Q-homology plane is a normal complex algebraic surface having trivial rational homology. We obtain a structure theorem for Q-homology planes with smooth locus of non-general type. We show that if a Q-homology plane contains a non-quotient…

Algebraic Geometry · Mathematics 2014-02-21 Karol Palka

Given a compact Riemannian manifold with boundary, we prove that the space of embedded, which may be improper, free boundary minimal hypersurfaces with uniform area and Morse index upper bound is compact in the sense of smoothly graphical…

Differential Geometry · Mathematics 2021-01-27 Qiang Guang , Zhichao Wang , Xin Zhou

We determine an upper bound for the cohomological dimension of the complement of a closed subset in a projective variety which possesses an appropriate stratification. We apply the result to several particular cases, including the…

Algebraic Geometry · Mathematics 2015-03-24 Mihai Halic , Roshan Tajarod

We prove that the basic intersection cohomology $ {I H}^{^{*}}_{_{\bar{p}}}{(M/\mathcal{F})}, $ where $\mathcal{F}$ is the singular foliation determined by an isometric action of a Lie group $G$ on the compact manifold $M$, is finite…

Differential Geometry · Mathematics 2012-09-19 M. Saralegi-Aranguren , R. Wolak

We study the moduli space of Higgs bundles on a compact Riemann surface. It was shown by Thaddeus and Hausel (in rank 2) and Markman (in general rank) that the rational cohomology ring of this space is generated by universal classes. In…

Algebraic Geometry · Mathematics 2007-05-23 Mridul Mehta

We study the topology of exact and Stein fillings of the canonical contact structure on the unit cotangent bundle of a closed surface $\Sigma_g$, where $g$ is at least 2. In particular, we prove a uniqueness theorem asserting that any Stein…

Symplectic Geometry · Mathematics 2017-07-25 Steven Sivek , Jeremy Van Horn-Morris

We show that the weight 0 part of the first cohomology of a complex algebraic variety $X$ is a topological invariant, and give an explicit description of its dimension using a topological construction of the normalization of $X$, where $X$…

Algebraic Geometry · Mathematics 2018-05-11 Morihiko Saito

The classical Theorem of Mumford states that a topologically regular complex algebraic surface in $\mathbb{C}^3$ with an isolated singular point is smooth. We proof that any Lipschitz regular complex algebraic set is smooth. No restriction…

Algebraic Geometry · Mathematics 2014-05-08 Lev Birbrair , Alexandre Fernandes , Edson Sampaio , Lê D. Trang

In this paper we try to look at the compactification of Teichmuller spaces from a tropical viewpoint. We describe a general construction for the compactification of algebraic varieties, using their amoebas, and we describe the boundary via…

Algebraic Geometry · Mathematics 2007-05-23 Daniele Alessandrini

We prove explicit and elementary formulas for the group homology and cohomology of a finite group with coefficients in any module. We describe in elementary terms the cohomology algebra $H^*(G,k)$ as a graded algebra for a finite group $G$…

Group Theory · Mathematics 2015-07-16 Sergei O. Ivanov , Nikolay N. Mostovsky

This paper generalizes classical results of Griffiths, Dolgachev and Steenbrink on the cohomology of hypersurfaces in weighted projective spaces. Given a $d$-dimensional projective simplicial toric variety $P$ and an ample hypersurface $X$…

alg-geom · Mathematics 2008-02-03 Victor V. Batyrev , David A. Cox

Let X be a smooth projective curve over a perfect field k of positive characteristic. This work investigates the relationship between stratified cohomology and group cohomology of the stratified fundamental group of X.

Algebraic Geometry · Mathematics 2025-07-29 V. Q. Bao , P. H. Hai , D. V. Thinh

Let M be a compact, orientable, mean convex 3-manifold with boundary. We show that the set of all simple closed curves in the boundary of M which bound unique area minimizing disks in M is dense in the space of simple closed curves in the…

Differential Geometry · Mathematics 2015-03-20 Baris Coskunuzer , Tolga Etgü

We study the monodromies and the limit mixed Hodge structures of families of complete intersection varieties over a punctured disk in the complex plane. For this purpose, we express their motivic nearby fibers in terms of the geometric data…

Algebraic Geometry · Mathematics 2021-03-11 Takahiro Saito , Kiyoshi Takeuchi