Radical extensions and crossed homomorphisms
نویسندگان
چکیده
منابع مشابه
Radical Extensions and Crossed Characters
E. Witt has given a theory of abelian extensions of fields containing sufficiently many roots of unity which consists essentially, as has been remarked before, in applying the theory of characters of finite abelian groups. There exists now a sufficiently developed theory of crossed characters, and it is the object of this note to show that a fairly complete and simple theory of radical extensio...
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to be quasidiagonal when B⊗K contains an approximate unit of projections which is quasi-central in E, cf. [Sa]. He identified, under certain conditions, the subgroup of KK(A,B) which the quasidiagonal extensions correspond to under Kasparov’s isomorphism Ext(A,B) ' KK(A,B). C. Schochet has removed some of Salinas’ conditions in [S], the result being that when A is a unital C-algebra in the boot...
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The notion of centrality for crossed modules was introduced by Norrie in her thesis [7], in which she studied the category of crossed modules CM from an algebraic point of view, showing suitable generalizations of group theoretic concepts and results. Subsequently, Norrie’s approach was followed by Carrasco, Cegarra and R.-Grandjeán. In [5] they proved that CM is an algebraic category (i.e. the...
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We study the flux homomorphism for closed forms of arbitrary degree, with special emphasis on volume forms and on symplectic forms. The volume flux group is an invariant of the underlying manifold, whose non-vanishing implies that the manifold resembles one with a circle action with homologically essential orbits.
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Jacobson's generalization [5, Theorem 8] of Wedderburn's theorem [8] states that an algebraic division algebra over a finite field is commutative. These algebras have the property that some power2 of each element lies in the center. Kaplansky observed in [7] that any division ring, or, more generally, any semisimple ring, in which some power of each element lies in the center is commutative. Ka...
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ژورنال
عنوان ژورنال: Bulletin of the Australian Mathematical Society
سال: 2001
ISSN: 0004-9727,1755-1633
DOI: 10.1017/s0004972700019729