Extended Dyer-Lashof algebras and modular coinvariants.
Extension categories and their homotopy
Extension of cross-sections and a generalized de Rham theorem.
Extension of topological homology theories to partially orderd sets.
Extension theory of infinite symmetric products
We present an approach to cohomological dimension theory based on infinite symmetric products and on the general theory of dimension called the extension dimension. The notion of the extension dimension ext-dim(X) was introduced by A. N. Dranishnikov [9] in the context of compact spaces and CW complexes. This paper investigates extension types of infinite symmetric products SP(L). One of the main ideas of the paper is to treat ext-dim(X) ≤ SP(L) as the fundamental concept of cohomological dimension...
Extensions du groupe additif
Extensions of best approximation and coincidence theorems.
Extensions of hom-Lie algebras in terms of cohomology
We study (non-abelian) extensions of a given hom-Lie algebra and provide a geometrical interpretation of extensions, in particular, we characterize an extension of a hom-Lie algebra by another hom-Lie algebra and discuss the case where has no center. We also deal with the setting of covariant exterior derivatives, Chevalley derivative, Maurer-Cartan formula, curvature and the Bianchi identity for the possible extensions in differential geometry. Moreover, we find a cohomological obstruction...
Extensions of homogeneous coordinate rings to -algebras.
Extensions of maps from suspensions of finite projective spaces.
Extensions of maps to the projective plane.
Extensions of symplectic groupoids and quantization.
Extensions of umbral calculus II: double delta operators, Leibniz extensions and Hattori-Stong theorems
We continue our programme of extending the Roman-Rota umbral calculus to the setting of delta operators over a graded ring with a view to applications in algebraic topology and the theory of formal group laws. We concentrate on the situation where is free of additive torsion, in which context the central issues are number- theoretic questions of divisibility. We study polynomial algebras which admit the action of two delta operators linked by an invertible power series, and make related constructions...
Extensions, retracts, and absolute neighborhood retracts in proper shape theory