Varieties of minimal rational tangents on double covers of projective space
نویسندگان
چکیده
منابع مشابه
On Fano Manifolds with Nef Tangent Bundles Admitting 1-dimensional Varieties of Minimal Rational Tangents
Let X be a Fano manifold of Picard number 1 with numerically effective tangent bundle. According to the principal case of a conjecture of Campana-Peternell’s, X should be biholomorphic to a rational homogeneous manifold G/P , where G is a simple Lie group, and P ⊂ G is a maximal
متن کاملEntropy of Rational Selfmaps of Projective Varieties
Let X ⊂ CP be an irreducible projective variety. Assume that F : X → X is a rational continuous map. Denote by h(F ) the entropy of F . In [Fri] we showed that h(F ) = logρ(F ) if X is smooth. Here ρ(F ) is the spectral radius of the induced linear map on the homology groups of X over the rationals. In the first part of this paper (§1) we show that this result is valid for any irreducible norma...
متن کاملExistence of Rational Points on Smooth Projective Varieties
Fix a number field k. We prove that if there is an algorithm for deciding whether a smooth projective geometrically integral k-variety has a k-point, then there is an algorithm for deciding whether an arbitrary k-variety has a k-point and also an algorithm for computing X(k) for any k-variety X for which X(k) is finite. The proof involves the construction of a one-parameter algebraic family of ...
متن کاملQuasi-projective covers of right $S$-acts
In this paper $S$ is a monoid with a left zero and $A_S$ (or $A$) is a unitary right $S$-act. It is shown that a monoid $S$ is right perfect (semiperfect) if and only if every (finitely generated) strongly flat right $S$-act is quasi-projective. Also it is shown that if every right $S$-act has a unique zero element, then the existence of a quasi-projective cover for each right act implies that ...
متن کاملInfinitesimal Deformations of Double Covers of Smooth Algebraic Varieties
The goal of this paper is to give a method to compute the space of infinitesimal deformations of a double cover of a smooth algebraic variety. This research was inspired by the analysis of Calabi–Yau manifolds that arise as smooth models of double covers of P branched along singular octic surfaces ([4, 3]). It is of considerable interest to determine the Hodge numbers for these manifolds, but t...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Mathematische Zeitschrift
سال: 2012
ISSN: 0025-5874,1432-1823
DOI: 10.1007/s00209-012-1125-6