Web let x be a scheme. We return to the problem of determining when a line bundle is ample. Web a quick final note. To see this, first note that any divisor of positive degree on a curve is ample. Web ometry is by describing its cones of ample and effective divisors ample(x) ⊂ eff(x) ⊂ n1(x)r.1 the closure in n1(x)r of ample(x) is the cone nef(x) of numerically effective.

We also investigate certain geometric properties. Write h h for a hyperplane divisor of p2 p 2. An ample divisor need not have global sections. Contact us +44 (0) 1603 279 593 ;

Web if the sheaves $\mathcal e$ and $\mathcal f$ are ample then $\mathcal e\otimes\mathcal f$ is an ample sheaf [1]. Let n_0 be an integer. Let p = p{e) be the associated projective bundle and l = op(l) the tautological line.

We also investigate certain geometric properties. For even larger n n, it will be also effective. To see this, first note that any divisor of positive degree on a curve is ample. The bundle e is ample. Web for large enough n n (roughly n ≈ 1/t n ≈ 1 / t ), the divisor an − c a n − c is ample.

F∗e is ample (in particular. Let p = p{e) be the associated projective bundle and l = op(l) the tautological line. The structure of the paper is as follows.

We Return To The Problem Of Determining When A Line Bundle Is Ample.

Web we will consider the line bundle l=o x (e) where e is e exceptional divisor on x.hereh 1 (s,q)= 0, so s is an ample subvariety by theorem 7.1, d hence the line. Contact us +44 (0) 1603 279 593 ; To see this, first note that any divisor of positive degree on a curve is ample. Let x and y be normal projective varieties, f :

An Ample Divisor Need Not Have Global Sections.

The pullback π∗h π ∗ h is big and. Web in this paper we show (for bundles of any rank) that e is ample, if x is an elliptic curve (§ 1), or if k is the complex numbers (§ 2), but not in general (§ 3). Web if the sheaves $\mathcal e$ and $\mathcal f$ are ample then $\mathcal e\otimes\mathcal f$ is an ample sheaf [1]. F∗e is ample (in particular.

Let P = P{E) Be The Associated Projective Bundle And L = Op(L) The Tautological Line.

I will not fill in the details, but i think that they are. The bundle e is ample. In a fourth section of the. Web let x be a scheme.

Web Ometry Is By Describing Its Cones Of Ample And Effective Divisors Ample(X) ⊂ Eff(X) ⊂ N1(X)R.1 The Closure In N1(X)R Of Ample(X) Is The Cone Nef(X) Of Numerically Effective.

Write h h for a hyperplane divisor of p2 p 2. We also investigate certain geometric properties. On the other hand, if c c is. Web for large enough n n (roughly n ≈ 1/t n ≈ 1 / t ), the divisor an − c a n − c is ample.

I will not fill in the details, but i think that they are. The pullback π∗h π ∗ h is big and. Web for large enough n n (roughly n ≈ 1/t n ≈ 1 / t ), the divisor an − c a n − c is ample. We return to the problem of determining when a line bundle is ample. Write h h for a hyperplane divisor of p2 p 2.