Results 221 to 230 of about 210,779 (252)

On Covers of Perfect Lie Algebras

Algebra Colloquium, 2011
A Lie algebra is said to be perfect when it coincides with its derived subalgebra. The paper is devoted to give a complete structure of covers of perfect Lie algebras. Also, similar to a result of Alperin and Gorenstein (1966) in group theory, it is shown that every automorphism of a finite dimensional perfect Lie algebra may be lifted to an ...
Salemkar, Ali Reza   +2 more
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Covering points in permutation algebras

Archiv der Mathematik, 2013
Let \(K\) be a normal subgroup of a finite group \(H\), and let \(b\) be a block of \(K\) with defect group \(D\) and Brauer correspondent \(b'\) in \(N_G(D)\). \textit{M. E. Harris} and \textit{R. Knörr} [Commun. Algebra 13, 1213-1218 (1985; Zbl 0561.20002)] have shown that the Brauer homomorphism \(\text{Br}_D\) induces a defect group preserving ...
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Triple Covers in Algebraic Geometry

American Journal of Mathematics, 1985
The aim of the paper under review is to develop a theory of triple covers in algebraic geometry. One of the most important general result obtained says that a triple cover \(X\to Y\) (with X and Y irreducible varieties over an algebraically closed field) is determined by a rank-two vector bundle E and a map \(S^ 3E\to \bigwedge^ 2E\), and conversely ...
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On covers of lie algebras

Communications in Algebra, 1996
In dealing with the central extensions of a finite group G one finds that although covers need not be isomorphic, for each such H there exists a cover for which H is a. homomorphic image [1]. For finite dimensional Lie algebras, covers are isomorphic. We shall show that the second property also holds for Lie algebras.
Peggy Batten, Ernest Stitzinger
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Effect Algebras Which Can Be Covered by MV-Algebras

International Journal of Theoretical Physics, 2002
Effect algebras are partial abelian monoids with a sort of negation operation: they yield a generalization of various kinds of structures currently used in the algebraic treatment of operator algebras, including Chang's MV algebras. The main result of this paper gives added evidence to the intuition that MV algebras stand to effect algebras as Boolean ...
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Covers of Algebraic Curves

2004
Let p be a prime number and let G be a finite group. The subgroup p(G) ⊂ G is defined as the group generated by all elements in G having as order a power of p. Equivalent definitions of p(G) are: (i) p(G) is the smallest normal subgroup such that the factor group G/p(G) has no elements with order p.
Jean Fresnel, Marius van der Put
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Irredundant Coverings, Tolerances, and Related Algebras

2018
This chapter deals with rough approximations defined by tolerance relations that represent similarities between the elements of a given universe of discourse. We consider especially tolerances induced by irredundant coverings of the universe U. This is natural in view of Pawlak’s original theory of rough sets defined by equivalence relations: any ...
Järvinen J., Radeleczki, S.
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Variational algorithms for linear algebra

Science Bulletin, 2021
Xiaosi Xu, Jinzhao Sun, Suguru Endo
exaly  

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