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Related papers: Deformations of log canonical singularities

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We characterize the left-handed noncommutative frames that arise from sheaves on topological spaces. Further, we show that a general left-handed noncommutative frame $A$ arises from a sheaf on the dissolution locale associated to the…

Rings and Algebras · Mathematics 2019-12-02 Karin Cvetko-Vah , Jens Hemelaer , Lieven Le Bruyn

We show that there exist flat surface bundles with closed leaves having non-trivial normal bundles. This leads us to compute the Abelianisation of surface diffeomorphism groups with marked points. We also extend a formula of Tsuboi that…

Geometric Topology · Mathematics 2014-10-01 Jonathan Bowden

We compare and contrast various relative cohomology theories that arise from resolutions involving semidualizing modules. We prove a general balance result for relative cohomology over a Cohen-Macaulay ring with a dualizing module, and we…

Commutative Algebra · Mathematics 2007-06-26 Sean Sather-Wagstaff , Tirdad Sharif , Diana White

We show that any commutative rationally ruled surface with a choice of anticanonical curve admits a 1-parameter family of noncommutative deformations parametrized by the Jacobian of the anticanonical curve, and show that many standard facts…

Algebraic Geometry · Mathematics 2019-07-29 Eric M. Rains

This paper investigates Levi flat structures from the perspective of structure sheaves. We employ formal integrability to construct a class of differential complexes, thereby providing a resolution for the structure sheaf and a global…

Complex Variables · Mathematics 2026-03-27 Qingchun Ji , Jun Yao

In this note we generalize the results of [KK10] and [KK20] by showing that if a closed subset V of X is "close enough" to being a union of log canonical centers, then it is Du Bois.

Algebraic Geometry · Mathematics 2022-11-03 János Kollár , Sándor J Kovács

This paper contributes to the theory of singularities of meromorphic linear ODEs in traceless $2\times2$ cases, focusing on their deformations and confluences. It is divided into two parts: The first part addresses individual singularities…

Classical Analysis and ODEs · Mathematics 2024-12-05 Martin Klimeš

We review Hopf-Galois extensions, in particular faithfully flat ones, accepted to be the noncommutative algebraic dual of a principal bundle. We also make a short digression into how quantum groups relate to Hopf-Galois extensions. Several…

Quantum Algebra · Mathematics 2024-02-28 William J. Ugalde

We show that flat families of stable 3-folds do not lead to proper moduli spaces in any characteristic $p>0$. As a byproduct, we obtain log canonical 4-fold pairs, whose log canonical centers are not weakly normal.

Algebraic Geometry · Mathematics 2026-03-04 János Kollár

We prove an effective vanishing theorem for direct images of log pluricanonical bundles of projective semi-log canonical pairs. As an application, we obtain a semipositivity theorem for direct images of relative log pluricanonical bundles…

Algebraic Geometry · Mathematics 2018-02-16 Osamu Fujino

We provide an axiomatic framework for the study of smooth extensions of generalized cohomology theories. Our main results are about the uniqeness of smooth extensions, and the identification of the flat theory with the R/Z-theory. In…

Algebraic Topology · Mathematics 2010-09-13 Ulrich Bunke , Thomas Schick

We show that the topological classification and the smooth classification are generically the same for certain families of plane curves in a semi-local case(the double local case). Especially we give the normal form of transversely jointed…

Geometric Topology · Mathematics 2007-05-23 Jean Paul Dufour , Yasuhiro Kurokawa

We know that semi-regular sub-varieties satisfy the variational Hodge conjecture i.e., given a family of smooth projective varieties $\pi:\mathcal{X} \to B$, a special fiber $\mathcal{X}_o$ and a semi-regular subvariety $Z \subset…

Algebraic Geometry · Mathematics 2016-12-05 Ananyo Dan , Inder Kaur

This paper introduces a two-parameter deformation of the cohomology of generalized flag varieties. One special case is the Belkale-Kumar deformation (used to study eigencones of Lie groups). Another picks out intersections of Schubert…

Algebraic Geometry · Mathematics 2018-07-12 Oliver Pechenik , Dominic Searles

By a recent result of Viehweg, projective manifolds with ample canonical class have a coarse moduli space, which is a union of quasiprojective varieties. In this paper, we prove that there are manifolds with ample canonical class that lie…

alg-geom · Mathematics 2008-02-03 Barbara Fantechi , Rita Pardini

In this article, we prove the Hodge conjecture for a desingularization of the moduli space of rank 2, semi-stable, torsion-free sheaves with fixed odd degree determinant over a very general irreducible nodal curve of genus at least 2. We…

Algebraic Geometry · Mathematics 2022-05-10 Ananyo Dan , Inder Kaur

Let f : Y -> X be a morphism of complex projective manifolds, and let F be a subsheaf of the tangent bundle which is closed under the Lie bracket, but not necessarily a foliation. This short paper contains an elementary and very geometric…

Algebraic Geometry · Mathematics 2010-03-30 Stefan Kebekus , Stavros Kousidis , Daniel Lohmann

We introduce a new cohomology theory related to deformations of Lie algebra morphisms. This notion involves simultaneous deformations of two Lie algebras and a homomorphism between them.

Quantum Algebra · Mathematics 2007-05-23 Yael Fregier

The classical Beauville-Bogomolov Decomposition Theorem asserts that any compact K\"ahler manifold with numerically trivial canonical bundle admits an \'etale cover that decomposes into a product of a torus, and irreducible,…

Algebraic Geometry · Mathematics 2016-11-08 Daniel Greb , Stefan Kebekus , Thomas Peternell

In this paper, we investigate the relations among various results concerning the minimal resolution of cyclic quotient singularities of the form $\mathbb{C}^2/G$. We refer to these as "bamboo-type" singularities, since the dual graphs of…

Algebraic Geometry · Mathematics 2026-04-07 Yukari Ito , Kohei Sato , Meral Tosun