共查询到20条相似文献,搜索用时 31 毫秒
1.
Mitsuru Kawazoe 《Journal of Pure and Applied Algebra》2006,204(3):602-615
Elliptic surfaces over an algebraically closed field in characteristic p>0 with multiple supersingular elliptic fibers, that is, multiple fibers of a supersingular elliptic curve, are investigated. In particular, it is shown that for an elliptic surface with q=g+1 and a supersingular elliptic curve as a general fiber, where q is the dimension of an Albanese variety of the surface and g is the genus of the base curve, the multiplicities of the multiple supersingular elliptic fibers are not divisible by p2. As an application of this result, the structure of false hyperelliptic surfaces is discussed on this basis. 相似文献
2.
We systematically develop Bridgeland's [7] and Bridgeland–Maciocia's [10] techniques for studying elliptic fibrations, and identify criteria that ensure 2-term complexes are mapped to torsion-free sheaves under a Fourier–Mukai transform. As an application, we construct an open immersion from a moduli of stable complexes to a moduli of Gieseker stable sheaves on elliptic threefolds. As another application, we give various 1–1 correspondences between fibrewise semistable torsion-free sheaves and codimension-1 sheaves on Weierstrass surfaces. 相似文献
3.
Rick Miranda 《Advances in Mathematics》2005,198(2):439-447
We present a construction of the bielliptic surfaces as covers of certain rational elliptic surfaces. 相似文献
4.
Gülay Karadoğan-Kaya 《Archiv der Mathematik》2007,89(4):315-325
In this paper, we study the structure, deformations and the moduli spaces of complex projective surfaces admitting genus two
fibrations over elliptic curves. We observe that a surface admitting a smooth fibration as above is elliptic, and we employ
results on the moduli of polarized elliptic surfaces to construct moduli spaces of these smooth fibrations. In the case of
nonsmooth fibrations, we relate the moduli spaces to the Hurwitz schemes
of morphisms of degree n from elliptic curves to the modular curve X(d), d ≥ 3. Ultimately, we show that the moduli spaces in the nonsmooth case are fiber spaces over the affine line
with fibers determined by the components of
.
Received: 30 August 2006 相似文献
5.
We study the potential density of rational points on double solids ramified along singular reduced sextic surfaces. Also, we investigate elliptic fibration structures on nonsingular sextic double solids defined over a perfect field of characteristic 5. 相似文献
6.
Hirotaka Ishida 《manuscripta mathematica》2005,118(4):467-483
In this paper, we find the lower bound for the relative Euler-Poincaré characteristic of a relatively minimal hyperelliptic
fibration with slope four. We prove the existence of hyperelliptic fibrations over an elliptic curve, which attain our bound. 相似文献
7.
Matthias Schütt 《Archiv der Mathematik》2006,87(4):309-319
We prove that the maximal singular fibres of an elliptic K3 surface have type I19 and
unless the characteristic of the ground field is 2. In characteristic 2, the maximal singular fibres are I18 and
. The paper supplements work of Shioda in [9] and [10].
Received: 23 September 2005 相似文献
8.
Halszka Tutaj-Gasińska 《Monatshefte für Mathematik》2005,144(3):225-231
In this paper we give some numerical conditions for a line bundle on a general blow-up of elliptic quasi bundles to give an embedding of order k. 相似文献
9.
S?awomir Cynk 《Journal of Number Theory》2009,129(8):1965-1975
We use a generalised Kummer construction to realise all but one known weight four newforms with complex multiplication and rational Fourier coefficients in Calabi-Yau threefolds defined over Q. The Calabi-Yau manifolds are smooth models of quotients of the Weil restrictions of elliptic curves with CM of class number three. 相似文献
10.
Xavier Roulleau 《manuscripta mathematica》2009,129(3):381-399
The elliptic curves on a surface of general type constitute an obstruction for the cotangent sheaf to be ample. In this paper,
we give the classification of the configurations of the elliptic curves on the Fano surface of a smooth cubic threefold. That
means that we give the number of such curves, their intersections and a plane model. This classification is linked to the
classification of the automorphism groups of theses surfaces. 相似文献
11.
We study relative Fourier–Mukai transforms on genus one fibrations with section, allowing explicitly the total space of the fibration to be singular and non-projective. Grothendieck duality is used to prove a skew–commutativity relation between this equivalence of categories and certain duality functors. We use our results to explicitly construct examples of semi-stable sheaves on degenerating families of elliptic curves. 相似文献
12.
Takeshi Harui 《Archiv der Mathematik》2005,84(2):131-147
In this paper it is shown that the gonality of curves on an elliptic ruled surface is twice the degree of the restriction of the bundle map and the Clifford index of such curves is computed by pencils of minimal degree, under certain numerical conditions. It is also proved that any pencil computing the gonality and the Clifford index of curves is composed with the restriction of the bundle map under some stronger conditions. On the other hand, we found some counterexample to the constancy of gonality and Clifford index in a linear system.Received: 2 December 2003 相似文献
13.
Michał Kapustka 《manuscripta mathematica》2009,130(1):121-135
We describe two ways to construct finite rational morphisms between fiber products of rational elliptic surfaces with section
and some Calabi–Yau varieties. We use them to construct correspondences between such fiber products that admit at most five
singular fibers and rigid Calabi–Yau threefolds. 相似文献
14.
Tomohiro Okuma 《Mathematische Annalen》2006,334(4):753-773
Every normal complex surface singularity with -homology sphere link has a universal abelian cover. It has been conjectured by Neumann and Wahl that the universal abelian
cover of a rational or minimally elliptic singularity is a complete intersection singularity defined by a system of ``splice
diagram equations'. In this paper we introduce a Neumann-Wahl system, which is an analogue of the system of splice diagram
equations, and prove the following.
If (X, o) is a rational or minimally elliptic singularity, then its universal abelian cover (Y, o) is an equisingular deformation of an isolated complete intersection singularity (Y0, o) defined by a Neumann-Wahl system. Furthermore, if G denotes the Galois group of the covering Y → X, then G also acts on Y0 and X is an equisingular deformation of the quotient Y0/G.
Dedicated to Professor Jonathan Wahl on his sixtieth birthday.
This research was partially supported by the Grant-in-Aid for Young Scientists (B), The Ministry of Education, Culture, Sports,
Science and Technology, Japan. 相似文献
15.
Kentaro Mitsui 《Journal of Pure and Applied Algebra》2019,223(2):553-570
We study the Frobenius base change of a torsor under a smooth algebraic group over a field of positive characteristic by relating it to the pushforward of the torsor under the Frobenius homomorphism. As an application, we determine the change of the multiplicity of a closed fiber of an elliptic surface by purely inseparable base changes with respect to the base curve in the case where the generic fiber is supersingular. 相似文献
16.
In a recent paper we proved a special case of a variant of Pink's Conjecture for a variety inside a semiabelian scheme: namely for any curve inside any scheme isogenous to a fibred product of two isogenous elliptic schemes. Here we go ahead with the programme of settling the conjecture for general abelian surface schemes by completing the proof for all non-simple surfaces. This involves some entirely new and crucial issues. 相似文献
17.
Adrian Langer 《Mathematische Zeitschrift》2000,235(3):591-614
We define Chern classes of reflexive sheaves using Wahl's relative local Chern classes of vector bundles. The main result
of the paper bounds contributions of singularities of a sheaf to the Riemann–Roch formula. Using it we are able to prove inequality
in Wahl's conjecture on relative asymptotic RR formula for rank 2 vector bundles. Moreover, we prove that if Wahl's conjecture
is true for a singularity then it is true for any its quotient. This implies Wahl's conjecture for quotient singularities
and for quotients of cones over elliptic curves.
Received March 2, 1998; in final form March 24, 1999 / Published online September 14, 2000 相似文献
18.
《Mathematische Nachrichten》2017,290(5-6):699-709
In this paper, we apply Borcea–Voisin's construction and give new examples of fourfolds containing a del Pezzo surface of degree six, which admit an elliptic fibration on a smooth threefold. Some of these fourfolds are Calabi–Yau varieties, which are relevant for the compactification of Type IIB string theory known as F‐theory. As a by‐product, we provide a new example of a Calabi–Yau threefold with Hodge numbers . 相似文献
19.
《Mathematische Nachrichten》2017,290(14-15):2132-2153
20.
Rüdiger Plantiko 《manuscripta mathematica》1995,87(1):527-543
If π:X→B is a non-Kählerian elliptic surface with generic fibreF, the moduli space of stable holomorphic vector bundles with torsion Chern classes onX has an induced fibred structure with base Pico(F) and the moduli space of stable parabolic bundles onB orb as fibre. This is specific to the non-Kähler case. 相似文献