Steenrod algebra

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Steenrod algebra

[′sten‚räd ′al·jə·brə]
(mathematics)
The cohomology groups of a topological space have additive operations on them, which can be added and multiplied so as to form the Steenrod algebra.
References in periodicals archive ?
If v denotes the total Wu class, w the total Stiefel-Whitney class of the tangent bundle, and Sq the total Steenrod square, then it is known that Sq(v) = w.
The isomorphism [kappa] preserves cup products and Steenrod squares so that:
Among the topics discussed by the research articles are symplectic Heegaard splittings and linked abelian groups, differential characters and the Steenrod squares, relative weight filtrations on completions of mapping class groups, symplectic automorphism groups of nilpotent quotient of fundamental groups of surfaces, and new examples of elements in the kernel of the Magnus representation of the Torelli groups.
0 may be chosen to extend the square S*(X) [cross product] a S*(X) [arrow right] S*(X) induced by the Alexander-Whitney map, and defines the Steenrod squares {[Sq.
Now, the Steenrod squares are also defined on the cohomology of the cocommutative Hopf algebras over Z/p, in particular, the Ext of the Steenrod algebras [L1][My]: Let A be a cocommutative Hopf algebra over Z/2, e.