Results 101 to 110 of about 813,424 (237)
Lorentzian homogeneous structures with indecomposable holonomy
Journal of the London Mathematical Society, Volume 113, Issue 5, May 2026.Abstract For a Lorentzian homogeneous space, we study how algebraic conditions on the isotropy group affect the geometry and curvature of the homogeneous space. More specifically, we prove that a Lorentzian locally homogeneous space is locally isometric to a plane wave if it admits an Ambrose–Singer connection with indecomposable, non‐irreducible ...
Steven Greenwood, Thomas Leistner
wiley +1 more source
Electric‐Current‐Assisted Nucleation of Zero‐Field Hopfion Rings
Advanced Materials, Volume 38, Issue 21, 13 April 2026.This work reports a novel and efficient nucleation protocol for 3D localized topological magnetic solitons‐hopfion rings in chiral magnets using pulsed electric currents. By using Lorentz transmission electron microscopy and topological analysis, we report characteristic features and extraordinary stability of hopfion rings in zero or inverted external
Xiaowen Chen +12 more
wiley +1 more source
What If Each Voxel Were Measured With a Different Diffusion Protocol?
Magnetic Resonance in Medicine, Volume 95, Issue 4, Page 2277-2290, April 2026.ABSTRACT Purpose Expansion of diffusion MRI (dMRI) both into the realm of strong gradients and into accessible imaging with portable low‐field devices brings about the challenge of gradient nonlinearities. Spatial variations of the diffusion gradients make diffusion weightings and directions non‐uniform across the field of view, and deform perfect ...
Santiago Coelho +7 more
wiley +1 more source
ADDITIVE GROUPS OF ASSOCIATIVE RINGS
Научный вестник МГТУ ГА, 2016 An abelian group is said to be semisimple if it is an additive group of at least one semisimple associative ring. It is proved that the description problem for semisimple groups is reduced to the case of reduced groups. As a consequence, it is shown that
E. I. Kompantseva
doaj
Families from supergroups and predictions for leptonic CP violation
Journal of High Energy Physics, 2017 As was shown in 1984 by Caneschi, Farrar, and Schwimmer, decomposing representations of the supergroup SU(M |N ), can give interesting anomaly-free sets of fermion representations of SU(M ) × SU(N ) × U(1).
S. M. Barr, Heng-Yu Chen
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Unsolvability of the isomorphism problem for [free abelian]-by-free groups
, 2008 The isomorphism problem for [free abelian]-by-free groups is unsolvable.Comment: added reference to a paper by Bruno Zimmermann containing a similar result for (free abelian)-by-surface ...
Levitt, Gilbert
core +3 more sources
Free compact groups I: Free compact abelian groups
Topology and its Applications, 1986 The structure of free compact abelian groups is investigated. A compact abelian group G is free compact abelian if and only if \(G\cong K\times {\hat {\mathbb{Q}}}^ a\times \prod_{p\in prime}{\mathbb{Z}}^ b_ p\), where \({\hat {\mathbb{Q}}}\) is the character group of the discrete group of rationals, K is a compact connected abelian group with dense ...
Hofmann, Karl Heinrich +1 more
openaire +1 more source
The classification problem for S-local torsion-free abelian groups of finite rank
, 2011 Suppose that n ⩾ 2 and that S, T are sets of primes. Then the classification problem for the S-local torsion-free abelian groups of rank n is Borel reducible to the classification problem for the T-local torsion-free abelian groups of rank n if and only ...
S. Thomas
semanticscholar +1 more source
Groups with minimax commutator subgroup [PDF]
International Journal of Group Theory, 2014 A result of Dixon, Evans and Smith shows that if $G$ is a locally (soluble-by-finite) group whose proper subgroups are (finite rank)-by-abelian, then $G$ itself has this property, i.e. the commutator subgroup of~$G$ has finite rank.
Francesco de Giovanni, Trombetti
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On the distance eigenvalues of Cayley graphs
پژوهشهای ریاضی, 2022 In this paper, graphs are undirected and loop-free and groups are finite. By Cn, Kn and Km,n we mean the cycle graph with n vertices, the complete graph with n vertices and the complete bipartite graph with parts size m and n, respectively.
Majid Arezoomand
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