of an ample line bundle, although there are several related classes of line bundles. Roughly speaking, positivity properties of a line bundle are related...
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a line bundle expresses the concept of a line that varies from point to point of a space. For example, a curve in the plane having a tangent line at...
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called semi-ample if some positive tensor power L ⊗ a {\displaystyle L^{\otimes a}} is basepoint-free. It follows that a semi-ample line bundle is nef. Semi-ample...
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anticanonical bundle is the corresponding inverse bundle ω − 1 {\displaystyle \omega ^{-1}} . When the anticanonical bundle of V {\displaystyle V} is ample, V {\displaystyle...
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tautological bundle is known as the tautological line bundle. The tautological bundle is also called the universal bundle since any vector bundle (over a compact...
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Moduli space (redirect from Moduli of vector bundles)
{\displaystyle i^{*}x_{0},\ldots ,i^{*}x_{n}} . Conversely, given an ample line bundle L → X {\displaystyle {\mathcal {L}}\to X} globally generated by n...
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interpretation of the ample line bundle over the moduli space of vector bundles on a compact Riemann surface, known as the Quillen determinant line bundle. It can be...
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Coherent sheaf (redirect from Vector bundle over a ringed space)
geometry. For example, the fact that the canonical bundle is a negative multiple of the ample line bundle O ( 1 ) {\displaystyle {\mathcal {O}}(1)} means...
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third power of an ample line bundle is normally generated. The Mumford–Kempf theorem states that the fourth power of an ample line bundle is quadratically...
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Positive form (section Positive line bundles)
Kodaira embedding theorem claims that a positive line bundle is ample, and conversely, any ample line bundle admits a Hermitian metric with − 1 Θ {\displaystyle...
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computing the Hilbert polynomial of line bundles on a curve. If a line bundle L {\displaystyle {\mathcal {L}}} is ample, then the Hilbert polynomial will...
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Iitaka dimension (redirect from Big line bundle)
varieties, and if L is a big line bundle on X, then f*L is a big line bundle on Y. All ample line bundles are big. Big line bundles need not determine birational...
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that if L is a big nef line bundle (for example, an ample line bundle) on a complex projective manifold with canonical line bundle K, then the coherent...
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there exists a very ample sheaf on X relative to S. Indeed, if X is proper, then an immersion corresponding to the very ample line bundle is necessarily closed...
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In algebraic geometry, given an ample line bundle L on a compact complex manifold X, Matsusaka's big theorem gives an integer m, depending only on the...
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Temple Seshadri constant, in algebraic geometry is an invariant of an ample line bundle L at a point P on an algebraic variety Seshadripuram, residential...
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canonical line bundle makes projective spaces prime examples of Fano varieties, equivalently, their anticanonical line bundle is ample (in fact very ample). Their...
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complete toric variety that has no non-trivial line bundle; thus, in particular, it has no ample line bundle. Definition 1.1.12 in Ginzburg, V., 1998. Lectures...
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K3 surface together with an ample line bundle L such that L is primitive (that is, not 2 or more times another line bundle) and c 1 ( L ) 2 = 2 g − 2 {\displaystyle...
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Equivariant sheaf (redirect from Linearlized line bundle)
linearizations of the trivial line bundle. See Example 2.16 of [1] for an example of a variety for which most line bundles are not linearizable. Given an...
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Seshadri constant (category Vector bundles)
In algebraic geometry, a Seshadri constant is an invariant of an ample line bundle L at a point P on an algebraic variety. It was introduced by Demailly...
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geometry, Reider's theorem gives conditions for a line bundle on a projective surface to be very ample. Let D be a nef divisor on a smooth projective surface...
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the theory of schemes, a related notion is ample line bundle. (For example, if L is an ample line bundle, some power of it is generated by global sections...
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Divisorial scheme (redirect from Ample family)
divisorial scheme is a scheme admitting an ample family of line bundles, as opposed to an ample line bundle. In particular, a quasi-projective variety...
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Coherent sheaf cohomology (category Vector bundles)
zero, L {\displaystyle L} is an ample line bundle on X {\displaystyle X} , and K X {\displaystyle K_{X}} a canonical bundle, then H j ( X , K X ⊗ L ) = 0...
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{\displaystyle X} is a smooth algebraic surface and L {\displaystyle L} is an ample line bundle on X {\displaystyle X} of degree d {\displaystyle d} , then for sufficiently...
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projective variety of dimension n ≥ 1 over a field, and let L be an ample line bundle on X. Then the section ring of L R = ⨁ j ≥ 0 H 0 ( X , L j ) {\displaystyle...
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Hilbert polynomial Φ {\displaystyle \Phi } . For a relatively very ample line bundle L ∈ Pic ( X ) {\displaystyle {\mathcal {L}}\in {\text{Pic}}(X)} and...
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appear as standard forms for varieties without a minimal model. Ample line bundle Fiber bundle Fibration Quasi-fibration Matsuki, Kenji (2002), Introduction...
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Appell–Humbert theorem (section Ample line bundles)
Lefschetz proved that the line bundle L {\displaystyle L} , associated to the Hermitian form H {\displaystyle H} is ample if and only if H {\displaystyle...
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