• sheaf cohomology is the application of homological algebra to analyze the global sections of a sheaf on a topological space. Broadly speaking, sheaf cohomology...
    36 KB (5,833 words) - 23:25, 7 March 2025
  • in algebraic geometry and the theory of complex manifolds, coherent sheaf cohomology is a technique for producing functions with specified properties. Many...
    26 KB (4,664 words) - 11:28, 9 October 2024
  • Especially in algebraic geometry and the theory of complex manifolds, sheaf cohomology provides a powerful link between topological and geometric properties...
    69 KB (11,082 words) - 14:18, 29 June 2025
  • to construct the resolutions needed to define sheaf cohomology (and other derived functors, such as sheaf Ext). There is a further group of related concepts...
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  • singular cohomology of topological spaces, but in fact, any constant sheaf on an irreducible variety has trivial cohomology (all higher cohomology groups...
    33 KB (5,016 words) - 23:02, 25 May 2025
  • cohomology Bounded cohomology BRST cohomology Čech cohomology Coherent sheaf cohomology Crystalline cohomology Cyclic cohomology Deligne cohomology Equivariant...
    44 KB (7,049 words) - 20:46, 13 January 2025
  • Thumbnail for De Rham cohomology
    de Rham cohomology and the sheaf cohomology of R _ {\textstyle {\underline {\mathbb {R} }}} . (Note that this shows that de Rham cohomology may also...
    19 KB (2,923 words) - 23:19, 2 May 2025
  • cohomology which are a special case of this: De Rham cohomology is the sheaf cohomology of the sheaf of locally constant R {\displaystyle \mathbb {R} }...
    18 KB (3,092 words) - 11:11, 24 December 2024
  • Thumbnail for Čech cohomology
    scheme, Čech and sheaf cohomology agree for any quasi-coherent sheaf. For the étale topology, the two cohomologies agree for any étale sheaf on X, provided...
    17 KB (3,378 words) - 22:42, 2 May 2025
  • has enough injectives, and consequently one can and does define the sheaf cohomology H i ⁡ ( X , − ) {\displaystyle \operatorname {H} ^{i}(X,-)} as the...
    19 KB (3,480 words) - 00:01, 5 June 2025
  • Rham cohomology to the singular cohomology given by integration is an isomorphism. The Poincaré lemma implies that the de Rham cohomology is the sheaf cohomology...
    10 KB (1,493 words) - 07:51, 18 April 2025
  • branch of mathematics, Serre duality is a duality for the coherent sheaf cohomology of algebraic varieties, proved by Jean-Pierre Serre. The basic version...
    18 KB (3,295 words) - 01:37, 25 May 2025
  • Coherent sheaf cohomology is a powerful technique, in particular for studying the sections of a given coherent sheaf. A quasi-coherent sheaf on a ringed...
    40 KB (6,934 words) - 00:04, 8 June 2025
  • Hodge theory, named after W. V. D. Hodge, is a method for studying the cohomology groups of a smooth manifold M using partial differential equations. The...
    28 KB (4,339 words) - 19:04, 13 April 2025
  • Thumbnail for Alexander Grothendieck
    their theory to show that sheaf cohomology may be defined as certain derived functors in this context. Homological methods and sheaf theory had already been...
    82 KB (8,677 words) - 07:46, 27 June 2025
  • equations, and the GAGA principle says that sheaf cohomology of an algebraic variety is the same as the sheaf cohomology of the analytic variety defined by the...
    32 KB (4,966 words) - 09:47, 13 June 2025
  • define group cohomology is to use topological cohomology theories (such as simplicial cohomology, singular cohomology or sheaf cohomology). More precisely...
    51 KB (9,835 words) - 08:49, 31 May 2025
  • complex manifolds. Alternatively, the Picard group can be defined as the sheaf cohomology group H 1 ( X , O X ∗ ) . {\displaystyle H^{1}(X,{\mathcal {O}}_{X}^{*})...
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  • the limit, are called Stein manifolds and their nature was to make sheaf cohomology groups vanish, on the other hand, the Grauert–Riemenschneider vanishing...
    124 KB (17,717 words) - 22:01, 1 July 2025
  • Ext functor (redirect from Ext sheaf)
    {g}}} is the universal enveloping algebra. For a topological space X, sheaf cohomology can be defined as H ∗ ( X , A ) = Ext ∗ ⁡ ( Z X , A ) . {\displaystyle...
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  • Local system (category Sheaf theory)
    topology which interpolates between cohomology with coefficients in a fixed abelian group A, and general sheaf cohomology in which coefficients vary from...
    14 KB (2,681 words) - 04:43, 11 November 2024
  • Here H0 means simply the sections over U, and the sheaf cohomology H1(2πiZ|U) is the singular cohomology of U. One can think of H1(2πiZ|U) as associating...
    3 KB (485 words) - 15:07, 22 June 2020
  • sheaf F on a Stein manifold X. They are significant both as applied to several complex variables, and in the general development of sheaf cohomology....
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  • In mathematics, a nonabelian cohomology is any cohomology with coefficients in a nonabelian group, a sheaf of nonabelian groups or even in a topological...
    1 KB (107 words) - 19:31, 30 September 2019
  • ordinary cohomology theories, it holds in extraordinary cohomology theories (such as topological K-theory and cobordism). From the point of view of sheaf cohomology...
    26 KB (3,763 words) - 21:58, 25 June 2025
  • formal properties. A perverse sheaf is an object C of the bounded derived category of sheaves with constructible cohomology on a space X such that the set...
    19 KB (2,265 words) - 05:36, 25 June 2025
  • Noetherian schemes. Čech cohomology and sheaf cohomology agree on an affine open cover. This makes it possible to compute the sheaf cohomology of P S n {\displaystyle...
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  • ideal sheaf is denoted O ( D ) {\displaystyle {\mathcal {O}}(D)} or L(D). By the exact sequence above, there is an exact sequence of sheaf cohomology groups:...
    41 KB (6,612 words) - 18:56, 28 June 2025
  • points, and its investigation was a major reason for the development of sheaf cohomology. Suppose f is an analytic function defined on a non-empty open subset...
    20 KB (3,893 words) - 10:37, 11 June 2025
  • nilpotent sheaf of ideals on T; for example, Spec(k) → Spec(k[x]/(x2)). Grothendieck showed that for smooth schemes X over C, the cohomology of the sheaf OX...
    15 KB (1,922 words) - 19:18, 25 May 2025