New formulas for cup-i products and fast computation of Steenrod squares
نویسندگان
چکیده
Operations on the cohomology of spaces are important tools enhancing descriptive power this computable invariant. For with mod 2 coefficients, Steenrod squares most significant these operations. Their effective computation relies formulas defining a cup-$i$ construction, structure (co)chains which is in its own right, having connections to lattice field theory, convex geometry and higher category theory among others. In article we present new use them introduce fast algorithm for finite simplicial complexes. forthcoming work axiomatically characterize construction they define, showing additionally that all other literature define same up isomorphism.
منابع مشابه
Computation of Cubical Steenrod Squares
Bitmap images of arbitrary dimension may be formally perceived as unions of m-dimensional boxes aligned with respect to a rectangular grid in R. Cohomology and homology groups are well known topological invariants of such sets. Cohomological operations, such as the cup product, provide higher-order algebraic topological invariants, especially important for digital images of dimension higher tha...
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چکیده ندارد.
15 صفحه اولSteenrod ∪ i - products on Bredon – Illman cohomology
Let G be a topological group acting on a space X. We construct a family of Steenrod’s ∪i -product [Ann. of Math. (2) 48 (1947) 290] on the Bredon–Illman cochain complex of X [Quart. J. Math. Oxford Ser. (2) 47 (1996) 199]. As corollaries, we get the existence of Steenrod squares on Bredon– Illman cohomology with appropriate coefficients as well as the triviality of the Gerstenhaber bracket indu...
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We present here a combinatorial method for computing cup-i products and Steenrod squares of a simplicial set X. This method is essentially based on the determination of explicit formulae for the component morphisms of a higher diagonal approximation (i.e., a family of morphisms measuring the lack of commutativity of the cup product on the cochain level) in terms of face operators of X. A genera...
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ژورنال
عنوان ژورنال: Computational Geometry: Theory and Applications
سال: 2023
ISSN: ['0925-7721', '1879-081X']
DOI: https://doi.org/10.1016/j.comgeo.2022.101921