Results 1 to 10 of about 34,889 (238)
Rings on Abelian torsion-free groups of finite rank [PDF]
This paper will be published in Beitr\"{a}ge zur Algebra und Geometrie / Contributions to Algebra and ...
E. I. Kompantseva, A. A. Tuganbaev
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Multiplication Groups of Abelian Torsion-Free Groups of Finite Rank
For an Abelian group $G$, any homomorphism $μ\colon G\otimes G\rightarrow G$ is called a \textsf{multiplication} on $G$. The set $\text{Mult}\,G$ of all multiplications on an Abelian group $G$ itself is an Abelian group with respect to addition; the group is called the \textsf{multiplication group} of $G$.
E. I. Kompantseva, A. A. Tuganbaev
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Hypertypes of torsion-free abelian groups of finite rank [PDF]
Let G be a torsion-free abelian group of finite rank n and let F be a full free subgroup of G. Then G/F is isomorphic to T1 ⊕ … ⊕ Tn, where T1 ⊆ T2 ⊆ … ⊆ Tn ⊆ ℚ/ℤ. It is well known that type T1 = inner type G and type Tn = outer type G. In this note we give two characterisations of type Ti for 1 < i < n.
Goeters, H. P. +2 more
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On the Classification Problem for Rank 2 Torsion-Free Abelian Groups [PDF]
We study here some foundational aspects of the classification problem for torsion-free abelian groups of finite rank. These are, up to isomorphism, the subgroups of the additive groups (Q^n, +), for some n = 1, 2, 3,....
Kechris, Alexander S.
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A note on torsion-free abelian groups of finite rank [PDF]
Let G be a torsion-free abelian group of rank n and X= {xl, *. , x,j a maximal set of rationally independent elements in G. It is well known that any g e G can be uniquely written g= oc1xl?+ +x, for some cci, . , ?C72, E Q, the rational numbers. This enables us to define, for any such (G, X), a collection of subgroups of Q and "natural" isomorphisms ...
Wickless, W., Vinsonhaler, C.
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Torsion-free crystallographic groups with indecomposable holonomy group II. [PDF]
Let K be a principal ideal domain, G a finite group, and M a KG-module which is a free K-module of finite rank on which G acts faithfully. A generalized crystallographic group is a non-split extension C of M by G such that conjugation in C induces the G ...
Bódi, Viktor +2 more
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Finitely generated abelian groups of units [PDF]
In 1960 Fuchs posed the problem of characterizing the groups which are the groups of units of commutative rings. In the following years, some partial answers have been given to this question in particular cases.
Del Corso, Ilaria
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Strongly Homogeneous Torsion Free Abelian Groups of Finite Rank [PDF]
An abelian group is strongly homogeneous if for any two pure rank 1 subgroups there is an automorphism sending one onto the other. Finite rank torsion free strongly homogeneous groups are characterized as the tensor product of certain subrings of algebraic number fields with finite direct sums of isomorphic subgroups of Q Q , the ...
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Fully inert subgroups of divisible Abelian groups [PDF]
A subgroup H of an Abelian group G is said to be fully inert if the quotient (H + phi(H)/H is finite for every endomorphism phi of G. Clearly, this is a common generalization of the notions of fully invariant, finite and finite-index subgroups.
Dikranjan, Dikran +3 more
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Trees, contraction groups, and Moufang sets [PDF]
We study closed subgroups $G$ of the automorphism group of a locally finite tree $T$ acting doubly transitively on the boundary. We show that if the stabiliser of some end is metabelian, then there is a local field $k$ such that $\mathrm{PSL}_2(k) \leq G
De Medts, Pierre-emmanuel Caprace, Tom
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