In algebraic geometry, a branch of mathematics, a Hilbert scheme is a scheme that is the parameter space for the closed subschemes of some projective space (or a more general projective scheme), refining the Chow variety. The Hilbert scheme is a disjoint union of projective subschemes corresponding to Hilbert polynomials. The basic theory of Hilbert schemes was developed by . Hironaka's example shows that non-projective varieties need not have Hilbert schemes.
The Hilbert scheme of classifies closed subschemes of projective space in the following sense: For any locally Noetherian scheme S, the set of S-valued points
of the Hilbert scheme is naturally isomorphic to the set of closed subschemes of that are flat over S. The closed subschemes of that are flat over S can informally be thought of as the families of subschemes of projective space parameterized by S. The Hilbert scheme breaks up as a disjoint union of pieces corresponding to the Hilbert polynomial of the subschemes of projective space with Hilbert polynomial P. Each of these pieces is projective over .
Grothendieck constructed the Hilbert scheme of -dimensional projective space as a subscheme of a Grassmannian defined by the vanishing of various determinants. Its fundamental property is that for a scheme , it represents the functor whose -valued points are the closed subschemes of that are flat over .
If is a subscheme of -dimensional projective space, then corresponds to a graded ideal of the polynomial ring in variables, with graded pieces . For sufficiently large all higher cohomology groups of with coefficients in vanish. Using the exact sequencewe have has dimension , where is the Hilbert polynomial of projective space. This can be shown by tensoring the exact sequence above by the locally flat sheaves , giving an exact sequence where the latter two terms have trivial cohomology, implying the triviality of the higher cohomology of . Note that we are using the equality of the Hilbert polynomial of a coherent sheaf with the Euler-characteristic of its sheaf cohomology groups.
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This is a glossary of algebraic geometry. See also glossary of commutative algebra, glossary of classical algebraic geometry, and glossary of ring theory. For the number-theoretic applications, see glossary of arithmetic and Diophantine geometry. For simplicity, a reference to the base scheme is often omitted; i.e., a scheme will be a scheme over some fixed base scheme S and a morphism an S-morphism.
In algebraic geometry, the Quot scheme is a scheme parametrizing sheaves on a projective scheme. More specifically, if X is a projective scheme over a Noetherian scheme S and if F is a coherent sheaf on X, then there is a scheme whose set of T-points is the set of isomorphism classes of the quotients of that are flat over T. The notion was introduced by Alexander Grothendieck. It is typically used to construct another scheme parametrizing geometric objects that are of interest such as a Hilbert scheme.
In mathematics, algebraic spaces form a generalization of the schemes of algebraic geometry, introduced by Michael Artin for use in deformation theory. Intuitively, schemes are given by gluing together affine schemes using the Zariski topology, while algebraic spaces are given by gluing together affine schemes using the finer étale topology. Alternatively one can think of schemes as being locally isomorphic to affine schemes in the Zariski topology, while algebraic spaces are locally isomorphic to affine schemes in the étale topology.
The student will learn state-of-the-art algorithms for solving differential equations. The analysis and implementation of these algorithms will be discussed in some detail.
We will study classical and modern deformation theory of schemes and coherent sheaves. Participants should have a solid background in scheme-theory, for example being familiar with the first 3 chapter
Explique le schéma implicite d'Euler, une méthode de résolution numérique des équations différentielles, axée sur les propriétés de stabilité et de convergence.
Explique les grilles de différence finie pour calculer les solutions de membranes élastiques à l'aide de l'équation et des méthodes numériques de Laplace.
Develop your promising idea into a successful business concept proposal, and launch it! Gain practical experience in the key steps of the venture creation process, including marketing and fundraising.
Develop your promising idea into a successful business concept proposal, and launch it! Gain practical experience in the key steps of the venture creation process, including marketing and fundraising.
Commitment is a key primitive which resides at the heart of several cryptographic protocols. Noisy channels can help realize information-theoretically secure commitment schemes; however, their imprecise statistical characterization can severely impair such ...
We investigate generalizations along the lines of the Mordell-Lang conjecture of the author's p-adic formal Manin-Mumford results for n-dimensional p-divisible formal groups F. In particular, given a finitely generated subgroup (sic) of F(Q(p)) and a close ...
This paper presents a first implementation of gradient, divergence, and particle tracing schemes for the EMC3 code, a stochastic 3D plasma fluid code widely employed for edge plasma and impurity transport modeling in tokamaks and stellarators. These scheme ...