Skip to content

Algebraic Geometry papers — page 22

alg-geomBrowse archive

A Lie algebra attached to a projective variety
Each choice of a Kähler class on a compact complex manifold defines an action of the Lie algebra on its total complex cohomology. If a nonempty set of such Kähler classes is given, then we…
Eduard Looijenga, Valery L. LuntsApr 24, 1996
Learn
On Classification of the extremal contraction from a smooth fourfold
We classify extremal divisorial contraction which contracts a divisor to a curve from a smooth fourfold. We prove the exceptional divisor is P2bundle or quadric bundle over a smooth curve and…
Hiromichi TakagiApr 19, 1996
Learn
Elementary counterexamples to Kodaira vanishing in prime characteristic
We give elementary counterexamples to Kodaira vanishing in prime characteristic constructed as the projectivization of Frobenius pull-backs of natural bundles on the incidence variety of points and…
N. Lauritzen, A. P. RaoApr 19, 1996
Learn
On top Chern classes of universal bundles on moduli spaces of rank two coherent sheaves on the projective plane, or How to calculate the correlation function in SYM N=2 Nf=4 quantum field theory on complex projective plane
We explain how to calculate the correlation function for SYM N=2 SO(3)-gauge QFT with 4 flavors in terms of top Chern classes of the universal bundles over the moduli spaces of rank 2 stable torsion…
Alexei L. Gorodentsev, Maxim I. LeyensonApr 18, 1996
Learn
A connectivity lemma for the Albanese map
I prove that for any complex projective variety X and a sufficiently large integer N all the fibers of Albanese map of the N-th configuration space of X are dominated by smooth connected…
M. RovinskyApr 17, 1996
Learn
Arf Rings and Characters
Algebraic curve branches can be classified according to their multiplicity sequences. Arf's solution to this problem using Arf closures and possible implementations of Henselization are discussed.
Sinan SertozApr 11, 1996
Learn
On a result of Imin Chen
We give another proof of Imin Chen's result that the jacobian of the modular curve X(p)non-split, for p a prime number, is isogeneous to the new part of the jacobian of X0(p2), using only…
Bas EdixhovenApr 10, 1996
Learn
On degree of polynomial mappings of C2 to C2
We prove two results about degree of polynomial mappings of C2 to C2.
Pavel KatsyloApr 6, 1996
Learn
On the constellations of Weierstrass points
We prove that the constellation of Weierstrass points characterizes the isomorphism-class of double covering of curves of genus large enough.
Fernando TorresApr 4, 1996
Learn
The Hodge filtration on nonabelian cohomology
This is partly a survey article on nonabelian Hodge theory, but we also give proofs of results that have only been announced elsewhere. In the introduction we discuss a wide range of recent work on…
Carlos SimpsonApr 4, 1996
Learn
Rationality of almost simple algebraic groups
We prove the stable rationality of almost simple algebraic groups, the connected components of the Dynkin diagram of anisotropic kernel of which contain at most two vertices. The (stable) rationality…
Nguyen Quoc ThangApr 2, 1996
Learn
Bornes effectives pour la torsion des courbes elliptiques sur les corps des nombres
We give an effective form of the theorem of Mazur-Kamienny-Merel on the torsion of elliptic curves over number fields.
Pierre ParentApr 2, 1996
Learn
Threefolds in P5 with a 3-dimensional family of plane curves
A classification theorem is given of smooth threefolds of P5 covered by a family of dimension at least three of plane integral curves of degree d≥ 2. It is shown that for such a…
Emilia Mezzetti, Dario PortelliApr 2, 1996
Learn
Higher Weil-Petersson Volumes of Moduli Spaces of Stable n-pointed Curves
Moduli spaces of compact stable n-pointed curves carry a hierarchy of cohomology classes of top dimension which generalize the Weil-Petersson volume forms and constitute a version of Mumford…
R. Kaufmann, Yu. Manin, D. ZagierApr 1, 1996
Learn
Seiberg-Witten invariants for manifolds with b+=1
In this paper we describe the Seiberg-Witten invariants, which have been introduced by Witten, for manifolds with b+=1. In this case the invariants depend on a chamber structure, and there exists…
Christian Okonek, Andrei TelemanMar 29, 1996
Learn
d-gonality of modular curves and bounding torsions
We study the problem of d-gonality of the modular curve X0(N). As a result, we can give an upperbound of the level N by means of d. This generalizes Ogg's result on hyperelliptic modular…
Khac Viet Nguyen, Masa-Hiko SaitoMar 29, 1996
Learn
Higher dimensional examples of manifolds whose adjoint bundles are not spanned
Let (X,L) be an n-dimensional polarized variety. Fujita's conjecture says that if Ln>1 then the adjoint bundle KX+nL is spanned and KX+(n+1)L is very ample. There are some examples…
Takeshi KawachiMar 28, 1996
Learn
On freeness theorem of the adjoint bundle on a normal surface
We extend Reider's freeness criterion to normal surfaces of characteristic 0. Let Y be a normal surface. Let D be a nef divisor on Y such that KY+D is a Cartier divisor. Let x be a point on Y.…
Takeshi KawachiMar 28, 1996
Learn
Equivariant Gromov - Witten Invariants
We develop general theory of equivariant quantum cohomology for ample Kahler manifolds and prove the mirror conjecture for projective complete intersections.
Alexander B. GiventalMar 27, 1996
Learn
Calabi-Yau Varieties and Pencils of K3 Surfaces
In this note, we give a list of Calabi-Yau hypersurfaces in weighted projective 4-spaces with the property that a hypersurface contains naturally a pencil of K3 variety. For completeness we also…
S. Hosono, B. H. Lian, S. -T. YauMar 24, 1996
Learn
Weak Hironaka theorem
The purpose of this note is to give a simple proof of the following theorem: Let X be a normal projective variety over an algebraically closed field k, char k = 0 and let D ⊂ X be…
Fedor Bogomolov, Tony PantevMar 24, 1996
Learn
Smoothness, Semistability, and Toroidal Geometry
We provide a new proof of the following result: Let X be a variety of finite type over an algebraically closed field k of characteristic 0, let Z⊂ X be a proper closed subset. There…
Dan Abramovich, Johan de JongMar 24, 1996
Learn
Singularities of Theta Divisors, and the Birational Geometry of Irregular Varieties
The purpose of this paper is to show how the generic vanishing theorems of M. Green and the second author can be used to settle several questions and conjectures concerning the geometry of irregular…
Lawrence Ein, Robert LazarsfeldMar 21, 1996
Learn
Espaces abstraits de morphismes et mutations
A transformation of morphisms of sheaves, called mutation, is used to build new moduli spaces of morphisms.
Jean-Marc DrézetMar 21, 1996
Learn
An intersection number for the punctual Hilbert scheme of a surface
Let S be a smooth projective surface, and consider the following two subvarieties of the Hilbert scheme parameterizing closed subschemes of S of length n: A = subschemes with support in a fixed…
Geir Ellingsrud, Stein Arild StrømmeMar 21, 1996
Learn
← PreviousPage 22Next →