English
Related papers

Related papers: Del Pezzo foliations with log canonical singularit…

200 papers

We extend the results of Pareschi on the constancy of the gonality and Clifford index of smooth curves in a complete linear system on Del Pezzo surfaces of degrees $\geq 2$ to the case of Del Pezzo surfaces of degree 1, where we explicitly…

Algebraic Geometry · Mathematics 2015-11-23 Andreas Leopold Knutsen

We study faithful actions with a dense orbit of abelian unipotent groups on quintic del Pezzo varieties over a field of characteristic zero. Such varieties are forms of linear sections of the Grassmannian of planes in a 5-dimensional vector…

Algebraic Geometry · Mathematics 2022-09-12 Adrien Dubouloz , Takashi Kishimoto , Pedro Montero

We classify all the effective anticanonical divisors on weak del Pezzo surfaces. Through this classification we obtain the smallest number among the log canonical thresholds of effective anticanonical divisors on a given Gorenstein…

Algebraic Geometry · Mathematics 2015-01-08 Jihun Park , Joonyeong Won

We find normal forms for del Pezzo surfaces of degree $2$ over algebraically closed fields of characteristic $2$. For each normal form, we describe the structure of the group of automorphisms of the surface. In particular, we classify all…

Algebraic Geometry · Mathematics 2023-05-19 Igor Dolgachev , Gebhard Martin

The Manin-Peyre conjecture is established for a split singular quintic del Pezzo surface with singularity type $\mathbf{A}_2$ and two split singular quartic del Pezzo surfaces with singularity types $\mathbf{A}_3+\mathbf{A}_1$ and…

Number Theory · Mathematics 2023-09-06 Xiaodong Zhao

A singular foliation $\mathcal F$ gives a partition of a manifold $M$ into leaves whose dimension may vary. Associated to a singular foliation are two complexes, that of the diffeological differential forms on the leaf space $M / \mathcal…

Differential Geometry · Mathematics 2023-03-15 David Miyamoto

We study holomorphic foliations tangent to singular real-analytic Levi-flat hypersurfaces in compact complex manifolds of complex dimension two. We give some hypotheses to guarantee the existence of dicritical singularities of these…

Complex Variables · Mathematics 2018-10-16 Andrés Beltrán , Arturo Fernández-Pérez , Hernán Neciosup

We consider the procedure that constructs log Calabi-Yau compactifications of weak Landau-Ginzburg models of Fano varieties. We apply it for del Pezzo surfaces and coverings of projective spaces of index one. For the coverings of degree…

Algebraic Geometry · Mathematics 2023-02-08 Victor Przyjalkowski

We classify quartic del Pezzo surface fibrations over the projective line via numerical invariants, giving explicit examples for small values of the invariants. For generic such fibrations, we describe explicitly the geometry of spaces of…

Algebraic Geometry · Mathematics 2013-01-31 Brendan Hassett , Yuri Tschinkel

We study special $\mathbb{G}_m$-equivariant degenerations of a smooth del Pezzo surface $X$ induced by valuations that are log canonical places of $(X,C)$ for a nodal anti-canonical curve $C$. We show that the space of special valuations in…

Algebraic Geometry · Mathematics 2025-03-11 Junyao Peng

We determine which singular del Pezzo surfaces are equivariant compactifications of G_a^2, to assist with proofs of Manin's conjecture for such surfaces. Additionally, we give an example of a singular quartic del Pezzo surface that is an…

Algebraic Geometry · Mathematics 2010-03-15 Ulrich Derenthal , Daniel Loughran

We construct the first examples of regular del Pezzo surfaces for which the irregularity (i.e. the dimension of the first cohomology group of the structure sheaf) is nonzero. We also find a restriction on the integer pairs that are possible…

Algebraic Geometry · Mathematics 2013-04-23 Zachary Maddock

We consider resolution of singularities for $1$-foliations on varieties of dimension at most three in positive characteristic. We prove that such singularities can be completely resolved if we allow tame regular Deligne--Mumford stacks as…

Algebraic Geometry · Mathematics 2025-08-12 Quentin Posva

We classify non-factorial nodal Fano threefolds with $1$ node and class group of rank $2$.

Algebraic Geometry · Mathematics 2024-10-04 Ivan Cheltsov , Igor Krylov , Jesus Martinez-Garcia , Evgeny Shinder

We classify the automorphism groups of del Pezzo surfaces of degrees one and two over an algebraically closed field of characteristic two. This finishes the classification of automorphism groups of del Pezzo surfaces in all characteristics.

Algebraic Geometry · Mathematics 2025-03-26 Igor Dolgachev , Gebhard Martin

We call a foliation $\mathcal{F}$ on a compact manifold infinitesimally rigid if its deformation cohomology $H^{1}(\mathcal{F},N\mathcal{F})$ vanishes. This paper studies infinitesimal rigidity for a distinguished class of Riemannian…

Differential Geometry · Mathematics 2025-02-03 Stephane Geudens , Florian Zeiser

In this paper we obtain 32 canonical forms for 3D piecewise smooth vector fields presenting the so called cusp-fold singularity. All these canonical forms are topologically distinct and collect the main topological aspects of the…

Dynamical Systems · Mathematics 2025-02-06 Tiago Carvalho , Jackson Cunha , Bruno Rodrigues Freita

This article focuses on the study of toric algebraic statistical models which correspond to toric Del Pezzo surfaces with Du Val singularities. A closed-form for the Maximum Likelihood Estimate of algebraic statistical models which…

Statistics Theory · Mathematics 2017-11-15 Dimitra Kosta

We generalize some results of Campana-P\u{a}un regarding foliations, slope stability, and positivity of log canonical bundles on smooth projective varieties to the case of smooth proper DM stacks admitting projective coarse moduli spaces.…

Algebraic Geometry · Mathematics 2026-05-27 Sebastian Casalaina-Martin , Shend Zhjeqi

We exhibit new examples of rational cubic fourfolds, parametrized by a countably infinite union of codimension-two subvarieties in the moduli space. Our examples are fibered in sextic del Pezzo surfaces over the projective plane; they are…

Algebraic Geometry · Mathematics 2020-12-17 Nicolas Addington , Brendan Hassett , Yuri Tschinkel , Anthony Várilly-Alvarado