Chenyang Xu
Let $K = K(C)$ be the function field of a smooth curve $C$. Applying the result of [Xu08], we prove that if $S/K$ is a degree one or two del Pezzo surface which can be completed to a generic family in the parametrizing space over $C$, then weak approximation holds at every place $c \in C$.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
Classification of exceptional log Del Pezzo surfaces with delta=1
对delta=1的特殊原木Del Pezzo曲面进行了分类。
We study del Pezzo varieties, higher-dimensional analogues of del Pezzo surfaces. In particular, we introduce ADE classification of del Pezzo varieties, show that in type A the dimension of non-conical del Pezzo varieties is bounded by $12 - d - r$, where $d$ is the degree and $r$ is the rank of the class group, and classify maximal del Pezzo varieties.
We study sextic del Pezzo surface fibrations via root stacks.
Weak Approximation for General Degree Two del Pezzo Surfaces
我们解决弱逼近的某些del Pezzo曲面定义的函数域的曲线。研究了具有两个A1奇点的二次del Pezzo曲面的光滑轨迹的有理连通性，证明了具有无平方判别式的二次del Pezzo曲面的弱逼近.
We classify codimension 2 well-formed and quasi-smooth weighted complete intersection del Pezzo surfaces.
Birational maps of del Pezzo fibrations
本文研究了平滑曲线芽上非奇异delPezzo纤维化的刚性。
On the coregularity of del Pezzo surfaces with du Val singularities
研究了具有du Val奇点的del Pezzo表面的核心正则性，发现正核心正则性表面对应于具有特殊性质的非平凡椭圆纤维化，且大多数表面核心正则性为0。
We give examples of K-unstable singular del Pezzo surfaces which are weighted hypersurfaces with index 2.
The maximal number of singular points on log del Pezzo surfaces
证明了Picard数为1的del Pezzo曲面至多有4个奇点.
A note on del Pezzo fibrations of degree 1
我们研究了具有终端奇点的1度delPezzo纤维化。本文将研究一次del Pezzo曲面上的奇异性与Kodaira椭圆奇异纤维分类之间的联系。通过这一研究，我们得到了关于具有终端奇点的一次delPezzo纤维化的双有理映射的几个结果。
We consider the problem of interpolating projective varieties through points and linear spaces. We show that del Pezzo surfaces satisfy weak interpolation.
We study irreducibility of families of degree 4 Del Pezzo surface fibrations over curves.
We discuss the rational points on del Pezzo surface of degree 1 and 2 over any finite field $\mathbb F_q$, and give out the explicit equations of del Pezzo surfaces that have unique rational point.
We completely classify K-stability of log del Pezzo hypersurfaces with index 2.
In this paper we consider del Pezzo surfaces with only log terminal singularities admitting an action of a finite simple group.
Degenerations of Del Pezzo surfaces and the Gromov-Witten invariants of the Hilbert Scheme of conics
利用退化方法研究了Del Pezzo曲面的示性数。
We consider del Pezzo surfaces with du Val singularities. We'll prove that a del Pezzo surface $X$ with du Val singularities has a $-K_X$-polar cylinder if and only if there exist tiger such that the support of this tiger does not contain anti-canonical divisor. Also we classify all del Pezzo surfaces $X$ such that $X$ has not any cylinders.
We estimate $δ$-invariants of some singular del Pezzo surfaces with quotient singularities, which we studied ten years ago. As a result, we show that each of these surfaces admits an orbifold Kähler--Einstein metric.
Del Pezzo surfaces with four log terminal singularities
本文研究了Picard数为一且具有四个log终端奇点的Del Pezzo表面的分类问题。
We classify del Pezzo surfaces with Du Val singularities that have infinite automorphism groups, and describe the connected components of their automorphisms groups.
We classify all of the log del Pezzo surfaces $S$ of index $a$ such that the volume $(-K_S^2)$ is larger than or equal to $2a$.
We classify RDP del Pezzo surfaces with global vector fields over arbitrary algebraically closed fields of characteristic $p \neq 2$. In characteristic $0$, every RDP del Pezzo surface $X$ is equivariant, that is, ${\rm Aut}_X = {\rm Aut}_{\widetilde{X}}$, where $\widetilde{X}$ is the minimal resolution of $X$, hence the classification of RDP del Pezzo surfaces with global vector fields is equivalent to the classification of weak del Pezzo surfaces with global vector fields. In this article, we show that if $p \neq 2,3,5,7$, then it is still true that every RDP del Pezzo surface is equivariant…
In this paper we prove that there are exactly two $G$-minimal surfaces which are $G$-birational to the quintic del Pezzo surface, where $G \cong C_5 \rtimes C_4$. These surfaces are the quintic del Pezzo surface itself and the surface $\mathbb{P}^1 \times \mathbb{P}^1$.
We construct a klt del Pezzo surface which is not globally F-split, over any algebraically closed field of positive characteristic.
The irreducibility of the spaces of rational curves on del Pezzo surfaces
我们证明了del Pezzo曲面上的有理曲线的空间要么是不可约的要么是空的，只有一个唯一的例外。
Log del Pezzo surfaces play the role of the opposite of surfaces of general type. We will completely classify all the log del Pezzo surfaces of rank 2 and Cartier index 3 with a unique singularity.
Automorphisms of Du Val del Pezzo surfaces
该研究针对自同构群为无限群的Du Val del Pezzo曲面，给出了其自同构群的描述结果。
In this paper, we classify del Pezzo foliations on projective manifolds of rank at least 3 and with log canonical singularities in the sense of McQuillan.
In this paper we prove that del Pezzo fibrations admit $\mathbb{G}_{a}^{3}$-structures if and only if they are $\mathbb{P}^2$-bundles over $\mathbb{P}^{1}$.
Almost del Pezzo manifolds
我们分类几乎del Pezzo流形在任意维n，即，具有大小不等的反正则丛-K_X的射影流形X，使得-K_X可被n-1整除.
In this paper we classify nodal rational non-$\mathbb{Q}$-factorial del Pezzo threefolds of degree 2 which can be $G$-birationally rigid for some subgroup $G\subset \operatorname{Aut}(X)$.
We classify Galois actions on Picard lattices of del Pezzo surfaces of degrees 1,2, and 3 giving rise to minimal surfaces with no cohomological obstructions to stable rationality.
For a log del Pezzo surface $S$, the fractional index $r(S)\in\mathbb{Q}_{>0}$ is the maximum of $r$ with which $-K_S$ can be written as $r$ times some Cartier divisor. We classify all the log del Pezzo surfaces $S$ with $r(S)\geq 1/2$, after the technique of Nakayama.
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 canonical del Pezzo surface.
Automorphisms of del Pezzo surfaces in odd characteristic
本文在奇正特征的代数闭域上，完成了del Pezzo曲面自同构群的分类工作。
Classification of low degree del Pezzo orbifolds II
本文在 Campana 框架下，对次数小于 6 的 del Pezzo 轨形按边界分量进行分类，补充了先前不可约边界情形的工作。
Birational models of del Pezzo fibrations
这是课堂讲稿系列的论文初稿。
Complexity of del Pezzo surfaces with du Val singularities
该研究针对具 du Val 奇点的 del Pezzo 曲面，完成了其复杂度的计算工作。
K-unstable singular del Pezzo surfaces without anticanonical polar cylinder
该研究证明了存在既不具备K-半稳定性也不含反典范极柱面的奇异del Pezzo曲面，丰富了代数几何中相关曲面的性质研究。
In this short note, we study the asymptotic Chow polystability of toric Del Pezzo surfaces appear in the moduli space of Kähler-Einstein Fano varieties constructed in [OSS16].
Varieties fibered into del Pezzo surfaces form a class of possible outputs of the minimal model program. It is known that del Pezzo fibrations of degrees $1$ and $2$ over the projective line with smooth total space satisfying the so-called $K^2$-condition are birationally rigid: their Mori fibre space structure is unique. This implies that they are not birational to any Fano varieties, conic bundles or other del Pezzo fibrations. In particular, they are irrational. The families of del Pezzo fibrations with smooth total space of degree $2$ are rather special, as for "most" families a general de…
Equations of log del Pezzo surfaces of index 2
C上对数末端奇点指数为\le 2的Del Pezzo曲面由Alekseev和Nikulin分类。在本文中，对于这些曲面中的每一个，我们找到一个适当的态射到射影空间。这些态射使我们能够在某些加权射影空间中用方程描述指数为\le 2的del Pezzo曲面。得到的结果是自然完成的类似结果的杜瓦尔，和Hidaka和渡边，描述德尔佩佐表面的指数为1。
Birational geometry of actions on del Pezzo surfaces
本文完成有限群在del Pezzo表面的正则一般自由作用的分类，解决了若干等变理查德几何中的开放问题。
Rigid affine cones over singular del Pezzo surfaces
本文完全确定了指数为1的拟光滑 log del Pezzo 曲面中反典范极化柱的存在性。
We classify del Pezzo surfaces of Picard number one with log canonical singularities admitting Q-Gorenstein smoothings.
We study full exceptional collections of line bundles on surfaces. We prove that any full strong exceptional collection of line bundles on a weak del Pezzo surface of degree $\ge 3$ is an augmentation in the sense of L.Hille and M.Perling, while for some weak del Pezzo surfaces of degree $2$ the above is not true. We classify smooth projective surfaces possessing a cyclic strong exceptional collection of line bundles of maximal length: we prove that they are weak del Pezzo surfaces and find all types of weak del Pezzo surfaces admitting such a collection. We find simple criteria of exceptional…
In this paper we give a criterion for birational rigidity of del Pezzo fibrations of degree 1 and 2 with only quotient singularities. As an application, we prove birational rigidity of suitable del Pezzo fibrations admitting an action of the Klein simple group.
A normal projective non-Gorenstein log-terminal surface $S$ is called a log del Pezzo surface of index three if the three-times of the anti-canonical divisor $-3K_S$ is an ample Cartier divisor. We classify all of the log del Pezzo surfaces of index three. The technique for the classification based on the argument of Nakayama.
We classify all the del Pezzo surfaces with $\frac{1}{3}(1,1)$- and $\frac{1}{4}(1,1)$-singularities having no floating $(-1)$-curves into 39 types.
The main aim of this article is to show that a very general 3-dimensional del Pezzo fibration of degree 1,2,3 is not stably rational except for a del Pezzo fibration of degree 3 belonging to explicitly described 2 families. Higher dimensional generalizations are also discussed and we prove that a very general del Pezzo fibration of degree 1,2,3 defined over the projective space is not stably rational provided that the anticanonical divisor is not ample.
This is a report of the author's talk at Algebra Symposium 2019 held at Tohoku University. We discuss some improvements of Mori's Bend and Break for sections of del Pezzo fibrations over $\mathbb P^1$.
We describe the effect of rational singularities on the Brauer group of a surface, and compute the Brauer groups of all singular del Pezzo surfaces over an algebraically closed field.
Birational properties of pencils of del Pezzo surfaces of degree 1 and 2
研究了1次和2次del Pezzo曲面上光滑Mori纤维化的双有理刚性问题。对于1度，我们得到了刚性和非刚性情况的完整描述。
To study syzygies of the Cox rings of del Pezzo surfaces, we calculate important syzygetic invariants such as the Hilbert functions, the Green-Lazarsfeld indices, the projective dimensions, and the Castelnuovo-Mumford regularities. Using these computations as well as the natural multigrading structures by the Picard groups of del Pezzo surfaces and Weyl group actions on Picard lattices, we determine the Betti diagrams of the Cox rings of del Pezzo surfaces of degree at most four.
On Gorenstein log del Pezzo Surfaces
本文首先给出了Picard数1 Gorenstein log del Pezzo曲面的奇异类型的完整列表以及与给定奇异类型同构的类的个数。然后给出了一种求Gorenstein log del Pezzo曲面所有奇异类型的方法。作为一个应用，我们提出了完整的列表的Dynkin型的Picard数2 Gorenstein日志del Pezzo表面。最后给出了相对极小Gorenstein log del Pezzo曲面的奇异类型的完整列表以及与给定奇异类型同构的类的个数。
In this paper we consider the classification of singularities (Du Val) and real structures (Wall) of weak Del Pezzo surfaces from an algorithmic point of view. It is well known that the singularities of weak Del Pezzo surfaces correspond to root subsystems. We present an algorithm which computes the classification of these root subsystems. We represent equivalence classes of root subsystems by unique labels. These labels allow us to construct examples of weak Del Pezzo surfaces with the corresponding singularity configuration. Equivalence classes of real structures of weak Del Pezzo surfaces a…
Ulrich Trichotomy on del Pezzo surfaces
该研究通过射影簇上Ulrich丛与箭图表示的对应关系，证明了任意给定极化下部分del Pezzo曲面满足Ulrich三分法，为代数几何中相关曲面的丛理论研究提供了新结论。
Hirschfeld classified split del Pezzo surfaces of degree at least three whose points are all contained on the lines in the surface. We continue his work and begin the classification of split degree two del Pezzo surfaces over finite fields whose points are all on the fifty-six exceptional curves of the surfaces.
On a rigidity criterion for del Pezzo fibrations over ${\mathbb P}^1$
讨论了${\mathbb P}^1$上1、2、3次del Pezzo曲面上Mori纤维化的刚性问题，并提出了如下猜想：这样的del Pezzo纤维化$V/{\mathbb P}^1$是双有理刚性的当且仅当它的拟有效阈值和附加阈值重合.我们证明了这个猜想的“只有当”部分。
We consider threefold del Pezzo fibrations over a curve germ whose central fiber is non-rational. Under the additional assumption that the singularities of the total space are at worst ordinary double points, we apply a suitable base change and show that there is a 1-to-1 correpspondence between such fibrations and certain non-singular del Pezzo fibrations equipped with a cyclic group action.
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。