Results 21 to 30 of about 36,092 (214)
International Journal of Mathematics and Mathematical Sciences, 2003 Let p be a prime. It is shown that an automorphism α of an abelian p-group A lifts to any abelian p-group of which A is a homomorphic image if and only if α=π idA, with π an invertible p-adic integer.
S. Abdelalim, H. Essannouni
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Extensions of group retractions
International Journal of Mathematics and Mathematical Sciences, 1980 In this paper a condition, which is necessary and sufficient, is determined when a retraction of a subgroup H of a torsion-free group G can be extended to a retraction of G.
Richard D. Byrd +3 more
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Separable torsion-free abelian E∗-groups
Journal of Pure and Applied Algebra, 1998 The first half of this paper characterizes the torsion-free separable abelian groups \(G\) whose endomorphism semigroup \(E(G)^*\) admits a unique addition; that is, the endomorphism ring \(E(G)\) is isomorphic to any ring \(S\) for which \(E(G)^*\) is isomorphic to \(S^*\).
Lubimcev, O. +2 more
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On Weakly Transitive Torsion-Free Abelian Groups
Journal of Mathematical Sciences, 2021 This short note adds new information on a previous paper with the same subject by \textit{B. Goldsmith} and \textit{L. Strüngmann} [Commun. Algebra 33, No. 4, 1177--1191 (2005; Zbl 1142.20032)]. The results are: Proposition 2. If \(A\) is a reduced torsion-free group with strongly indecomposable pure subgroups and the set \(T(A)\) of types of all its ...
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TORSION-FREE WEAKLY TRANSITIVE ABELIAN GROUPS
Communications in Algebra, 2005 ABSTRACT We introduce the notion of weak transitivity for torsion-free abelian groups. A torsion-free abelian group G is called weakly transitive if for any pair of elements x, y ∈ G and endomorphisms ϕ, ψ ∈ End(G) such that xϕ = y, yψ = x, there exists an automorphism of G mapping x onto y.
Goldsmith, Brendan, Strungmann, Lutz
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Non-unitarisable representations and random forests [PDF]
, 2008 We establish a connection between Dixmier's unitarisability problem and the expected degree of random forests on a group. As a consequence, a residually finite group is non-unitarisable if its first L2-Betti number is non-zero or if it is finitely ...
Epstein, Inessa, Monod, Nicolas
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Torsion-free abelian groups are Borel complete
Annals of Mathematics, 2018 We prove that the Borel space of torsion-free Abelian groups with domain $ω$ is Borel complete, i.e., the isomorphism relation on this Borel space is as complicated as possible, as an isomorphism relation. This solves a long-standing open problem in descriptive set theory, which dates back to the seminal paper on Borel reducibility of Friedman and ...
Paolini G., Shelah S.
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Structure of Finite-Dimensional Protori
Axioms, 2019 A Structure Theorem for Protori is derived for the category of finite-dimensional protori (compact connected abelian groups), which details the interplay between the properties of density, discreteness, torsion, and divisibility within a finite ...
Wayne Lewis
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General relativity as a biconformal gauge theory
Nuclear Physics B, 2019 We consider the conformal group of a space of dimn=p+q, with SO(p,q) metric. The quotient of this group by its homogeneous Weyl subgroup gives a principal fiber bundle with 2n-dim base manifold and Weyl fibers.
James T. Wheeler
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Almost completely decomposable torsion free abelian groups [PDF]
Proceedings of the American Mathematical Society, 1974 A finite rank torsion free abelian group G G is almost completely decomposable if there exists a completely decomposable subgroup C C with finite index in G G . The minimum of [ G : C ] [G:C] over all completely decomposable subgroups C
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