scholarly journals Surfaces of general type with q = 2 are rigidified

2018 ◽  
Vol 20 (07) ◽  
pp. 1750084 ◽  
Author(s):  
Wenfei Liu

Let [Formula: see text] be a minimal smooth projective surface of general type with irregularity [Formula: see text]. We show that, if [Formula: see text] has a nontrivial holomorphic automorphism acting trivially on the cohomology with rational coefficients, then it is a surface isogenous to a product. As a consequence of this geometric characterization, one infers that no nontrivial automorphism of surfaces of general type with [Formula: see text] (which are not necessarily minimal) can be homotopic to the identity. In particular, such surfaces are rigidified in the sense of Fabrizio Catanese.

2016 ◽  
Vol 68 (1) ◽  
pp. 67-87
Author(s):  
Hirotaka Ishida

AbstractLet S be a surface of general type. In this article, when there exists a relatively minimal hyperelliptic fibration whose slope is less than or equal to four, we give a lower bound on the Euler–Poincaré characteristic of S. Furthermore, we prove that our bound is the best possible by giving required hyperelliptic fibrations.


2001 ◽  
Vol 130 (1) ◽  
pp. 161-174 ◽  
Author(s):  
JIN-XING CAI

It is proved that, for a complex minimal smooth projective surface S of general type with a pencil of genus g = 3 or 4, any Abelian automorphism group of S is of order [les ] 12K2S + 96(g − 1), provided K2S > 8(g − 1)2, where KS is the canonical divisor of S.


2001 ◽  
Vol 33 (3) ◽  
pp. 265-274 ◽  
Author(s):  
MARGARIDA MENDES LOPES ◽  
RITA PARDINI

A minimal surface of general type with pg(S) = 0 satisfies 1 [les ] K2 [les ] 9, and it is known that the image of the bicanonical map φ is a surface for K2S [ges ] 2, whilst for K2S [ges ] 5, the bicanonical map is always a morphism. In this paper it is shown that φ is birational if K2S = 9, and that the degree of φ is at most 2 if K2S = 7 or K2S = 8.By presenting two examples of surfaces S with K2S = 7 and 8 and bicanonical map of degree 2, it is also shown that this result is sharp. The example with K2S = 8 is, to our knowledge, a new example of a surface of general type with pg = 0.The degree of φ is also calculated for two other known surfaces of general type with pg = 0 and K2S = 8. In both cases, the bicanonical map turns out to be birational.


2013 ◽  
Vol 2013 (679) ◽  
pp. 1-22 ◽  
Author(s):  
Sai-Kee Yeung

Abstract The smallest topological Euler–Poincaré characteristic supported on a smooth surface of general type is 3. In this paper, we show that such a surface has to be a fake projective plane unless h1, 0(M) = 1. Together with the classification of fake projective planes given by Prasad and Yeung, the recent work of Cartwright and Steger, and a proof of the arithmeticity of the lattices involved in the present article, this gives a classification of such surfaces.


Author(s):  
MENG CHEN ◽  
ZHIJIE J. CHEN

Let X be a complex nonsingular projective threefold of general type. Suppose the canonical system of X is composed of a pencil, i.e. dimΦ∼KX∼(X)=1. It is often important to understand birational invariants of X such as pg(X), q(X), h2(OX) and χ(OX) etc. In this paper, we mainly study the irregularity of X.We may suppose that ∼KX∼ is free of base points. There is a natural fibration f[ratio ]X→C onto a nonsingular curve after the Stein factorization of Φ∼KX∼. Let F be a general fibre of f, then we know that F is a nonsingular projective surface of general type. Set b[ratio ]=g(C) and pg(F), q(F) for the respective invariants of F. The main result is the following theorem.


2014 ◽  
Vol 57 (1) ◽  
pp. 143-165 ◽  
Author(s):  
DAVIDE FRAPPORTI ◽  
ROBERTO PIGNATELLI

AbstractA mixed quasi-étale quotient is the quotient of the product of a curve of genus at least 2 with itself by the action of a group which exchanges the two factors and acts freely outside a finite subset. A mixed quasi-étale surface is the minimal resolution of its singularities. We produce an algorithm computing all mixed quasi-étale surfaces with given geometric genus, irregularity and self-intersection of the canonical class. We prove that all irregular mixed quasi-étale surfaces of general type are minimal. As an application, we classify all irregular mixed quasi-étale surfaces of general type with genus equal to the irregularity, and all the regular ones with K2 > 0, thus constructing new examples of surfaces of general type with χ = 1. We mention the first example of a minimal surface of general type with pg = q = 1 and Albanese fibre of genus bigger than K2.


2021 ◽  
Vol 21 (1) ◽  
pp. 143-148
Author(s):  
Nguyen Bin

Abstract In this note, we construct three new infinite families of surfaces of general type with canonical map of degree 2 onto a surface of general type. For one of these families the canonical system has base points.


2018 ◽  
Vol 19 (1) ◽  
pp. 209-229
Author(s):  
Xin Lü

In this paper, we construct the first examples of complex surfaces of general type with arbitrarily large geometric genus whose canonical maps induce non-hyperelliptic fibrations of genus $g=4$, and on the other hand, we prove that there is no complex surface of general type whose canonical map induces a hyperelliptic fibrations of genus $g\geqslant 4$ if the geometric genus is large.


2016 ◽  
Vol 223 (1) ◽  
pp. 66-86 ◽  
Author(s):  
YIFAN CHEN

Let$S$be a smooth minimal complex surface of general type with$p_{g}=0$and$K^{2}=7$. We prove that any involution on$S$is in the center of the automorphism group of$S$. As an application, we show that the automorphism group of an Inoue surface with$K^{2}=7$is isomorphic to$\mathbb{Z}_{2}^{2}$or$\mathbb{Z}_{2}\times \mathbb{Z}_{4}$. We construct a$2$-dimensional family of Inoue surfaces with automorphism groups isomorphic to$\mathbb{Z}_{2}\times \mathbb{Z}_{4}$.


1996 ◽  
Vol 143 ◽  
pp. 1-11 ◽  
Author(s):  
Kazuhiro Konno

This is a continuation of [5]. In the present part, we study irregular even surfaces of general type with K < 4χ, where K and χ denote respectively a canonical divisor and the holomorphic Euler-Poincaré characteristic. As the first main theorem, we show the following: THEOREM 1. For any irregular even surface of general type with K < 4χ, the image of the Albanese map is a curve.


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