Seshadri constants on algebraic surfaces

نویسنده

  • Thomas Bauer
چکیده

0. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. Seshadri constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Very ample line bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Bounds on global Seshadri constants . . . . . . . . . . . . . . . . . . . . . . . . 9 4. The degree of sub-maximal curves . . . . . . . . . . . . . . . . . . . . . . . . . . 14 5. On the number of sub-maximal curves . . . . . . . . . . . . . . . . . . . . . . . 17 6. Seshadri constants of polarized abelian surfaces . . . . . . . . . . . . . . . . . . 19 7. The nef cone of an abelian surface . . . . . . . . . . . . . . . . . . . . . . . . . 24 8. Multiple point Seshadri constants on abelian surfaces . . . . . . . . . . . . . . . 30

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Seshadri constants and very ample divisors on algebraic surfaces

A broadly applicable geometric approach for constructing nef divisors on blow ups of algebraic surfaces at n general points is given; it works for all surfaces in all characteristics for any n. This construction is used to obtain substantial improvements for currently known lower bounds for n point Seshadri constants. Remarks are included about a range of applications to classical problems invo...

متن کامل

Seshadri Constants on Rational Surfaces with Anticanonical Pencils

We provide an explicit formula for Seshadri constants of any polarizations on rational surfaces X such that dim |−KX | ≥ 1. As an application, we discuss relationship between singularities of log del Pezzo surfaces and Seshadri constants of their anticanonical divisors. We also give some remarks on higher order embeddings of del Pezzo surfaces.

متن کامل

Seshadri constants on the self - product of an elliptic curve

The purpose of this paper is to study Seshadri constants on the self-product E × E of an elliptic curve E. We provide explicit formulas for computing the Seshadri constants of all ample line bundles on the surfaces considered. As an application, we obtain a good picture of the behaviour of the Seshadri function on the nef cone.

متن کامل

Seshadri Constants via Lelong Numbers

One of Demailly’s characterizations of Seshadri constants on ample line bundles works with Lelong numbers of certain positive singular hermitian metrics. In this note sections of multiples of the line bundle are used to produce such metrics and then to deduce another formula for Seshadri constants. It is applied to compute Seshadri constants on blown up products of curves, to disprove a conject...

متن کامل

Seshadri Constant for a Family of Surfaces

The aim of this note is to study local and global Seshadri constants for a family of smooth surfaces with prescribed polarization. We shall first observe that given α being smaller than the square root of the degree of polarization, the set of local Seshadri constants in the range (0, α] is finite. This in particular implies that the square root of the degree of polarization is the only possibl...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1999