English
Related papers

Related papers: On pluri-half-anticanonical system of LeBrun twist…

200 papers

We classify surfaces of general type whose bicanonical map is composed with a rational map of degree 2 onto a rational or ruled surface.

Algebraic Geometry · Mathematics 2007-05-23 Giuseppe Borrelli

We investigate the following conjecture: all compact non-K\"ahler complex surfaces admit birational structures. After Inoue-Kobayashi-Ochiai, the remaining cases to study are essentially surfaces in class VII_0^+. In case of Kato surfaces…

Complex Variables · Mathematics 2016-01-13 Georges Dloussky

This paper is concerned with projective rationally connected surfaces $X$ with canonical singularities and having non-zero pluri-forms, i.e. $(\Omega_X^1)^{[\otimes m]}$ has non-zero global sections for some m > 0, where…

Algebraic Geometry · Mathematics 2014-06-06 Wenhao Ou

For any $\Lambda>0$, let $\mathcal{M}_{n,\Lambda}$ denote the space containing all locally Lipschitz minimal graphs of dimension $n$ and of arbitrary codimension $m$ in Euclidean space $\mathbb{R}^{n+m}$ with uniformly bounded 2-dilation…

Differential Geometry · Mathematics 2021-09-21 Qi Ding , J. Jost , Y. L. Xin

In this paper we investigate a family of Moishezon twistor spaces on the connected sum of 4 complex projective planes, which can be regarded as a direct generalization of the twistor spaces on 3CP^2 of double solid type studied by Poon and…

Differential Geometry · Mathematics 2010-09-17 Nobuhiro Honda

We study the real dynamics of a family of rational surface automorphisms obtained from quadratic birational maps of $\pcc$ that preserve a cuspidal cubic and whose critical orbits have lengths $(1,m,n)$ with $1+m+n\ge 10$. Passing to the…

Dynamical Systems · Mathematics 2025-09-03 Kyounghee Kim , Insung Park

We give some explicit upper bounds on the effective birationality of the canonical or anti-canonical system for a singular surface. In particular, we show that for any surface $X$ with $\epsilon$-lc singularity and the canonical divisor…

Algebraic Geometry · Mathematics 2025-08-26 Pinxian Bie

The space Loc(m,S) of rank m flat bundles on a closed surface S is K_2-symplectic. A threefold M bounding S gives rise a K_2-Lagrangian in Loc(m,S) given by the flat bundles on S extending to M. We generalize this, replacing the zero…

Algebraic Geometry · Mathematics 2026-01-13 Alexander B. Goncharov , Maxim Kontsevich

The purpose of this article is to study the deformations of smooth surfaces $X$ of general type whose canonical map is a finite, degree 2 morphism onto a minimal rational surface or onto $\mathbf F_1$, embedded in projective space by a very…

Algebraic Geometry · Mathematics 2010-06-01 Francisco Javier Gallego , Miguel González , Bangere P. Purnaprajna

We carry out an analysis of the canonical system of a minimal complex surface of general type with irregularity q>0. Using this analysis we are able to sharpen in the case q>0 the well known Castelnuovo inequality K^2>=3p_g+q-7. Then we…

Algebraic Geometry · Mathematics 2015-05-27 Margarida Mendes Lopes , Rita Pardini , Gian Pietro Pirola

Using the techniques of Bayer--Macr\`i, we determine the walls in the movable cone of the Mukai system of rank two for a general K3 surface $S$ of genus two. We study the (essentially unique) birational map to $S^{[5]}$ and decompose it…

Algebraic Geometry · Mathematics 2020-09-02 Isabell Hellmann

Let S be a minimal complex surface of general type with p_g=0 such that the bicanonical map of S is not birational and let Z be the bicanonical image. In [M.Mendes Lopes, R.Pardini, "Enriques surfaces with eight nodes", Math. Zeit. 241 (4)…

Algebraic Geometry · Mathematics 2007-05-23 Margarida Mendes Lopes , Rita Pardini

The configuration space C^n of unordered n-tuples of distinct points on a torus T^2 is a non-singular complex algebraic variety. We study holomorphic self-maps of C^n and prove that for n>4 any such map F either carries the whole of C^n…

Complex Variables · Mathematics 2007-05-23 Yoel Feler

Renormalizations can be considered as building blocks of complex dynamical systems. This phenomenon has been widely studied for iterations of polynomials of one complex variable. Concerning non-polynomial hyperbolic rational maps, a recent…

Dynamical Systems · Mathematics 2015-08-10 Guizhen Cui , Wenjuan Peng , Lei Tan

We exploit techniques from classical (real and complex) algebraic geometry for the study of the standard twistor fibration $\pi:\mathbb{CP}^{3}\to S^{4}$. We prove three results about the topology of the twistor discriminant locus of an…

Differential Geometry · Mathematics 2019-03-12 Amedeo Altavilla , Edoardo Ballico

In this document we present a twistor correspondence for half-flat almost-Grassmannian structures on real and complex manifolds. We provide foundational results regarding local theory in the complex setting and a global correspondence when…

Differential Geometry · Mathematics 2023-04-18 Matthew Lam

We give a concrete example of an infinite sequence of $(p_n, q_n)$-lens spaces $L(p_n, q_n)$ with natural triangulations $T(p_n, q_n)$ with $p_n$ taterahedra such that $L(p_n, q_n)$ contains a certain non-orientable closed surface which is…

Geometric Topology · Mathematics 2008-09-11 Chuichiro Hayashi , Miwa Iwakura

We give explicit constructions of all the numerical Campedelli surfaces, i.e the minimal surfaces of general type with K^2=2 and p_g=0, whose fundamental group has order 9. There are three families, one with fundamental group equal to Z_9…

Algebraic Geometry · Mathematics 2007-05-23 Margarida Mendes Lopes , Rita Pardini

We verify that if $M$ is a compact minimal hypersurface in $\mathbb{S}^{n+1}$ whose squared length of the second fundamental form satisfying $0\leq |A|^2-n\leq\frac{n}{22}$, then $|A|^2\equiv n$ and $M$ is a Clifford torus. Moreover, we…

Differential Geometry · Mathematics 2016-05-25 Hongwei Xu , Zhiyuan Xu

From the point of view of uniform bounds for the birationality of pluricanonical maps, irregular varieties of general type and maximal Albanese dimension behave similarly to curves. In fact Chen-Hacon showed that, at least when their…

Algebraic Geometry · Mathematics 2009-10-08 Miguel Angel Barja , Martí Lahoz , Juan Carlos Naranjo , Giuseppe Pareschi