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We develop an approach that allows to construct semiorthogonal decompositions of derived categories of surfaces with cyclic quotient singularities whose components are equivalent to derived categories of local finite dimensional algebras.…

Algebraic Geometry · Mathematics 2020-04-09 Joseph Karmazyn , Alexander Kuznetsov , Evgeny Shinder

We prove a rigidity result for foliations on surfaces of genus two, which can be seen as a generalization to higher genus of Herman's theorem on circle diffeomorphisms and, correspondingly, flows on the torus. We prove in particular that,…

Dynamical Systems · Mathematics 2021-06-08 Selim Ghazouani , Corinna Ulcigrai

Let $pi:X\to\Delta$ be a one-parameter degeneration whose central fiber $X_0$ has a single ordinary double point. The nearby- and vanishing-cycle formalism determines a canonical perverse sheaf on $X_0$, obtained from the variation morphism…

Algebraic Geometry · Mathematics 2026-04-07 Abdul Rahman

By using the ultracontractivity of a reference diffusion semigroup, Krylov's estimate is established for a class of degenerate SDEs with singular drifts, which leads to existence and pathwise uniqueness by means of Zvonkin's transformation.…

Probability · Mathematics 2018-04-30 Xing Huang , Feng-Yu Wang

Let T -> S be a finite flat morphism of degree two between regular integral schemes of dimension at most two (and with 2 invertible), having regular branch divisor D. We establish a bijection between Azumaya quaternion algebras on T and…

Algebraic Geometry · Mathematics 2012-07-18 Asher Auel , R. Parimala , V. Suresh

We prove the symmetrising trace conjecture of Brou\'e, Malle and Michel for the generic Hecke algebra associated to the exceptional irreducible complex reflection group $G_{13}$. Our result completes the proof of the conjecture for the…

Representation Theory · Mathematics 2020-01-17 Christina Boura , Eirini Chavli , Maria Chlouveraki

Let $S$ be a certain affine algebraic surface over $\mathbb{Q}$ such that it admits a regular map to $\mathbb{A}^2/\mathbb{Q}$. We show that any non-trivial torsion line bundle in the relative Picard group $Pic^0\left(S/\mathbb{A}^2\right)$…

Algebraic Geometry · Mathematics 2024-09-11 Kalyan Banerjee , Azizul Hoque

We consider circle patterns on surfaces with complex projective structures. We investigate two symplectic forms pulled back to the deformation space of circle patterns. The first one is Goldman's symplectic form on the space of complex…

Geometric Topology · Mathematics 2024-04-29 Wai Yeung Lam

The correspondence between del Pezzo surfaces and field theory models over the complex numbers or for split real forms is extended to other real forms, in particular to those compatible with supersymmetry. Specifically, all theories of the…

High Energy Physics - Theory · Physics 2009-11-07 Pierre Henry-Labordere , Bernard Julia , Louis Paulot

We argue that for a smooth surface S, considered as a ramified cover over the projective plane branched over a nodal-cuspidal curve B one could use the structure of the fundamental group of the complement of the branch curve to understand…

Algebraic Geometry · Mathematics 2011-06-29 Michael Friedman , Mina Teicher

We study minimal del Pezzo surfaces of degree 1 with a conic bundle over a finite field $\mathbb{F}_q$ according to the action of the absolute Galois group on the singular fibers (which is known as their type). We give a lower bound on the…

Algebraic Geometry · Mathematics 2026-03-23 Manoy T. Trip

If we have a braid group acting on a derived category by spherical twists, how does a lift of the longest element of the symmetric group act? We give an answer to this question, using periodic twists, for the derived category of modules…

Representation Theory · Mathematics 2015-01-12 Joseph Grant

We study the topology of Hitchin fibrations via abelian surfaces. We establish the P=W conjecture for genus $2$ curves and arbitrary rank. In higher genus and arbitrary rank, we prove that P=W holds for the subalgebra of cohomology…

Algebraic Geometry · Mathematics 2021-07-21 Mark Andrea A. de Cataldo , Davesh Maulik , Junliang Shen

We classify smooth weak del Pezzo surfaces with global vector fields over an arbitrary algebraically closed field $k$ of arbitrary characteristic $p \geq 0$. We give a complete description of the configuration of $(-1)$- and $(-2)$-curves…

Algebraic Geometry · Mathematics 2024-12-25 Gebhard Martin , Claudia Stadlmayr

We prove the Lipman-Zariski conjecture for complex surface singularities with $p_g - g - b \le 2$. Here $p_g$ is the geometric genus, $g$ is the sum of the genera of the exceptional curves and $b$ is the first Betti number of the dual…

Algebraic Geometry · Mathematics 2020-09-15 Hannah Bergner , Patrick Graf

This article is devoted to examples of (orbifold) K\"ahler groups from the perspective of the so-called Shafarevich conjecture on holomorphic convexity. It aims at pointing out that every quasi-projective complex manifold with an…

Algebraic Geometry · Mathematics 2016-11-29 Philippe Eyssidieux

We study admissible subcategories of the bounded derived category of a smooth projective surface that are supported on the exceptional locus of a birational morphism. We prove that if $f:X\to Y$ is a birational morphism of smooth projective…

Algebraic Geometry · Mathematics 2026-04-21 Ari Krishna

We consider the equivariant Kasparov category associated to an \'etale groupoid, and by leveraging its triangulated structure we study its localization at the "weakly contractible" objects, extending previous work by R. Meyer and R. Nest.…

K-Theory and Homology · Mathematics 2024-12-23 Christian Bönicke , Valerio Proietti

In his book "Cubic forms" Manin discovered that del Pezzo surfaces are related to root systems. To explain the many numerical coincidences Batyrev conjectured that a universal torsor on a del Pezzo surface can be embedded in a certain…

Algebraic Geometry · Mathematics 2008-05-31 Vera Serganova , Alexei Skorobogatov

We prove that any genus-2 Lefschetz fibration without reducible fibers and with ``transitive monodromy'' is holomorphic. The latter condition comprises all cases where the number of singular fibers is not congruent to 0 modulo 40. An…

Symplectic Geometry · Mathematics 2007-05-23 Bernd Siebert , Gang Tian