Results 51 to 60 of about 36,092 (214)

On automorphism groups of Toeplitz subshifts

Discrete Analysis, 2017
On automorphism groups of Toeplitz subshifts, Discrete Analysis 2017:11, 19 pp. A discrete dynamical system is a space $X$ with some kind of structure, together with a map $\sigma\colon X\to X$ that preserves the structure.
Sebastian Donoso, Fabien Durand, Alejandro Maass, Samuel Petite   +3 more
doaj   +1 more source

Localizations of torsion-free abelian groups

Journal of Algebra, 2004
The author considers the localizations of torsion-free Abelian groups, more precisely, the localizations of free groups, of cotorsion-free groups, and of finite rank Butler groups. For Abelian groups \(A,B\) a homomorphism \(\alpha\colon A\to B\) is said to be a `localization' of \(A\) if, for all \(f\colon A\to B\), there is a unique \(\varphi\colon B\
openaire   +1 more source

On torsion-free abelian 𝑘-groups [PDF]

Proceedings of the American Mathematical Society, 1987
It is shown that a knice subgroup with cardinality ℵ 1 {\aleph _1} , of a torsion-free completely decomposable abelian group, is again completely decomposable. Any torsion-free abelian k k -group of cardinality ℵ n {\aleph _n} has
Manfred Dugas, K. M. Rangaswamy
openaire   +1 more source

Higher homotopy of groups definable in o-minimal structures

, 2009
It is known that a definably compact group G is an extension of a compact Lie group L by a divisible torsion-free normal subgroup. We show that the o-minimal higher homotopy groups of G are isomorphic to the corresponding higher homotopy groups of L.
Berarducci, Alessandro, Mamino, Marcello, Otero, Margarita   +2 more
core   +2 more sources

Residually rationally solvable one‐relator groups

Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract We show that the intersection of the rational derived series of a one‐relator group is rationally perfect and is normally generated by a single element. As a corollary, we characterise precisely when a one‐relator group is residually rationally solvable.
Marco Linton
wiley   +1 more source

Torsion classes of extended Dynkin quivers over commutative rings

Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract For a Noetherian R$R$‐algebra Λ$\Lambda$, there is a canonical inclusion torsΛ→∏p∈SpecRtors(κ(p)Λ)$\mathop {\mathsf {tors}}\Lambda \rightarrow \prod _{\mathfrak {p}\in \operatorname{Spec}R}\mathop {\mathsf {tors}}(\kappa (\mathfrak {p})\Lambda)$, and each element in the image satisfies a certain compatibility condition.
Osamu Iyama, Yuta Kimura
wiley   +1 more source

The classification problem for extensions of torsion-free abelian groups, I [PDF]

, 2022
Martino Lupini
openalex   +1 more source

Profinite direct sums with applications to profinite groups of type ΦR$\Phi _R$

Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract We show that the ‘profinite direct sum’ is a good notion of infinite direct sums for profinite modules, having properties similar to those of direct sums of abstract modules. For example, the profinite direct sum of projective modules is projective, and there is a Mackey's formula for profinite modules described using these sums.
Jiacheng Tang
wiley   +1 more source

KULIKOV'S PROBLEM ON UNIVERSAL TORSION-FREE ABELIAN GROUPS

Journal of the London Mathematical Society, 2003
Let T be an abelian group and lambda an uncountable regular cardinal. We consider the question of whether there is a lambda-universal group G^* among all torsion-free abelian groups G of cardinality less than or equal to lambda satisfying Ext(G,T)=0.
Shelah, Saharon, Strüngmann, Lutz
openaire   +3 more sources

Abelian Livšic theorems for Anosov flows

Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract We give two short proofs of the abelian Livšic theorem of Gogolev and Rodriguez Hertz. We show that these proofs may be extended to give new abelian Livšic theorems for positive density sets of null‐homologous orbits and for amenable covers.
Richard Sharp
wiley   +1 more source