Skip to content

Algebraic Geometry papers — page 46

alg-geomBrowse archive

Semistable Minimal Models of Threefolds in Positive or Mixed Characteristic
We extend the minimal model theorem to the 3-dimensional schemes which are projective and have semistable reduction over the spectrum of a Dedekind ring.
Yujiro KawamataMar 5, 1993
Learn
Existence and Deformation Theory for Scalar-Flat Kaehler Metrics on Compact Complex Surfaces
Let M be a compact complex surface which admits a Kaehler metric whose scalar curvature has integral zero; and suppose the fundamental group of M does not contain an Abelian subgroup of finite index.…
Claude LeBrun, Michael SingerFeb 23, 1993
Learn
A Finiteness Theorem for Quaternionic-Kaehler Manifolds with Positive Scalar Curvature
We study the topology and geometry of those compact Riemannian (4n)-manifolds (M,g), n > 1, with positive scalar curvature and holonomy in Sp(n)Sp(1). Up to homothety, we show that there are only…
Claude LeBrunFeb 23, 1993
Learn
Intersection homology Betti numbers
A generalization of the formula of Fine and Rao for the ranks of the intersection homology groups of a complex algebraic variety is given. The proof uses geometric properties of intersection homology…
Alan H. DurfeeFeb 12, 1993
Learn
Lefschetz Fixed Point Theorem and Lattice Points in Convex Polytopes
A simple convex lattice polytope defines a torus-equivariant line bundle over a toric variety . Atiyah and Bott's Lefschetz fixed-point theorem is applied to the torus action on…
Sacha Sardo-InfirriFeb 9, 1993
Learn
On the surjectivity of Wahl maps on a general curve
This paper explores the geometric meaning of the failure of certain kinds of Wahl maps to surject on a general curve. Sufficient conditions for surjectivity are given. An approach used by Voisin to…
Roberto PaolettiFeb 9, 1993
Learn
A note on non-vanishing and applications
Let X be a normal variety over the field of complex numbers with log terminal singularities and the canonical divisor KX being Q-Gorenstein. Assume that L is an ample line bundle over…
Marco Andreatta, Jarosław A. WiśniewskiFeb 1, 1993
Learn
Bounds of automorphism groups of genus 2 fibrations
For a complex surface of general type with a relatively minimal genus 2 fibration, the bounds of the orders of the automorphism group of the fibration, of its abelian subgroups and of its cyclic…
Zhi-Jie ChenJan 29, 1993
Learn
Rational curves on Calabi-Yau manifolds: verifying predictions of Mirror Symmetry
Mirror symmetry, a phenomenon in superstring theory, has recently been used to give tentative calculations of several numbers in algebraic geometry. In this paper, the numbers of lines and conics on…
Sheldon KatzJan 27, 1993
Learn
The topology of the space of rational curves on a toric variety
Let X be a compact toric variety. Let Hol denote the space of based holomorphic maps from CP1 to X which lie in a fixed homotopy class. Let Map denote the corresponding space of continuous…
Martin A. GuestJan 24, 1993
Learn
The Geometry of Bielliptic Surfaces in P4
In 1988 Serrano Ser, using Reider's method, discovered a minimal bielliptic surface in 4. Actually he showed that there is a unique family of such surfaces and that they have degree…
A. Aure, W. Decker, K. Hulek et al.Jan 20, 1993
Learn
Minimal Cohomology Classes and Jacobians
We show that on the Jacobian (JC,θ) of a smooth curve C of genus g, any effective cycle in JC with cohomology class θd/d! is a translate of Wg-d(C) or -Wg-d(C). We then use this…
Olivier DebarreJan 6, 1993
Learn
Non-trivial Linear Systems on Smooth Plane Curves
Let C be a smooth plane curve of degree d defined over an algebraically closed field k. A base point free complete very special linear system grn on C is trivial if there exists an…
Marc Coppens, Takao KatoJan 6, 1993
Learn
Lines on Calabi Yau complete intersections, mirror symmetry, and Picard Fuchs equations
A relation between the number of rational curves of fixed degree on Calabi Yau threefolds and the Picard Fuchs equations, which was suggested as part of the study of mirror symmetry, is verified in…
A. Libgober, J. TeitelbaumJan 4, 1993
Learn
Automorphisms and the Kähler cone of certain Calabi-Yau manifolds
For the Calabi-Yau threefolds X constructed by C. Schoen as fiber products of generic rational elliptic surfaces, we show that the action of the automorphism group of X on the Kähler cone of X…
Antonella Grassi, David R. MorrisonDec 22, 1992
Learn
The enumeration of simultaneous higher-order contacts between plane curves
Using the Semple bundle construction, we derive an intersection-theoretic formula for the number of simultaneous contacts of specified orders between members of a generic family of degree d plane…
Susan Jane Colley, Gary KennedyDec 8, 1992
Learn
On the stable rationality of X/G
Let G be a connected, reductive algeraic group whose Dynkin diagram contains no components of type G2, F4, E6, E7 or E8. That is, all the components are of classical type. Suppose…
Amnon NeemanDec 4, 1992
Learn
Algebraic approximations of holomorphic maps from Stein domains to projective manifolds
It is shown that every holomorphic map f from a Runge domain Ω of an affine algebraic variety S into a projective algebraic manifold X is a uniform limit of Nash algebraic maps fν defined…
Jean-Pierre Demailly, Laszlo Lempert, Bernard ShiffmanDec 1, 1992
Learn
Stable pairs on curves and surfaces
We describe stability conditions for pairs consisting of a coherent sheaf and a homomorphism to a fixed coherent sheaf on a projective variety. The corresponding moduli spaces are constructed for…
Daniel Huybrechts, Manfred LehnNov 9, 1992
Learn
Elliptic Three-folds I: Ogg-Shafarevich Theory
We calculate the Tate-Shafarevich group of an elliptic three-fold f:X→ S when X and S are regular and f is flat, relating it to the Brauer group of X and S. We show that given…
I. Dolgachev, M. GrossOct 30, 1992
Learn
Erratum to "The Homogeneous Coordinate Ring of a Toric Variety", along with the original paper
This submission consists of two papers: 1) an erratum that corrects an error in the proof of Proposition 4.3 in my paper "The Homogeneous Coordinate Ring of a Toric Variety", and 2) the…
David A. CoxOct 22, 1992
Learn
Stable pairs, linear systems and the Verlinde formula
We study the moduli problem of pairs consisting of a rank 2 vector bundle and a nonzero section over a fixed smooth curve. The stability condition involves a parameter; as it varies, we show that the…
Michael ThaddeusOct 19, 1992
Learn
Reductive group actions on Kähler manifolds
We prove that the action of a reductive complex Lie group on a Kähler manifold can be linearized in the neighbourhood of a fixed point, provided that the restriction of the action to some compact…
Eugene Lerman, Reyer SjamaarOct 14, 1992
Learn
Degrees of Curves in Abelian Varieties
The degree of a curve C in a polarized abelian variety (X,λ) is the integer d=C·λ. When C generates X, we find a lower bound on d which depends on n and the degree of the…
Olivier DebarreOct 13, 1992
Learn
Points of Low Degree on Smooth Plane Curves
The purpose of this note is to provide some applications of Faltings' recent proof of S. Lang's conjecture to smooth plane curves. Let C be a smooth plane curve defined by an equation of…
Olivier Debarre, Matthew KlassenOct 13, 1992
Learn
← PreviousPage 46Next →