Results 311 to 320 of about 12,663,351 (362)

The higher lower central series

Israel Journal of Mathematics, 1991
With every group \(G\) the author associates a family of groups \(\Gamma_ n(G)\) each of which is equal to the \(n\)-th term \(\gamma_ n(U)\) where \(U\) is a projective object in the category of epimorphisms \(U\twoheadrightarrow G\) with the kernel in the \(n\)-th centre of \(U\). It is noticed that these groups coincide with R. Baer's invariants and
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Central Series for Groups with Action and Leibniz Algebras

Georgian Mathematical Journal, 2002
The notion of central series for groups with action on itself is introduced. An analogue of Witt's construction is given for such groups. A certain condition is found for the action and the corresponding category is defined.
T. Datuashvili
semanticscholar   +1 more source

The Generation of the Lower Central Series

Canadian Journal of Mathematics, 1965
Let G be a finite group with commutator subgroup G′. In an earlier paper (4) it was shown that each element of G′ is a product of n commutators, if 4n ≥ |G′|. The object of this paper is to improve this result in two directions:Theorem 1a. If (n + 2)!n! > 2|G′| — 2, then each element of G′ is a product of n commutators.Theorem 1b. If G is a p-group,
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Central Mean Subspace in Time Series

Journal of Computational and Graphical Statistics, 2009
We propose a notion of central mean dimension reduction subspace for time series {xt} which does not require specification of a model but seeks to find a p×d matrix Φd, d≤p, so that the d×1 vector ΦdTXt−1, where Xt−1=(xt−1, …, xt−p)T for some p≥1, includes all the information about xt that is available from E(xt|Xt−1).
Jin-Hong Park, T. N. Sriram, Xiangrong Yin   +2 more
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Opioid-associated central sleep apnea: a case series

Sleep and Breathing, 2008
Subjects on methadone maintenance for drug addiction have been reported to have central sleep apnea (CSA). However, there are few reports of disordered breathing in patients receiving opioids for chronic pain.We report on six patients (ages 41-68, two females, body mass index 27-34, morphine equivalent doses 120-420 mg/day, Epworth Scales 7-21 ...
M A, Alattar, S M, Scharf
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The order-types of central series

Mathematical Proceedings of the Cambridge Philosophical Society, 1965
Letbe a series of type Ω of the group G. By this we mean that Ω is an ordered set (we shall always understand ‘ordered’ to mean ‘totally ordered’) and Λσ and Vσ are subgroups of G satisfying(i) Vσ ◃ Λσ for all σεΩ,(ii) Λσ ≤ Vτ if σ < τ(iii) , where G−1 denotes the set of elements ≠ 1 of G and Λσ−Vσ the set of elements of Λσ not belonging to Vσ,(iv ...
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Central Derivatives of Eisenstein Series and Height Pairings

The Annals of Mathematics, 1997
This important paper provides evidence that the derivatives at the center of symmetry of certain Siegel-Eisenstein series are related to arithmetical algebraic geometry. More precisely (following the introduction), the nonlinear Fourier coefficients of such derivatives can be expressed as a sum of terms associated to the primes (including infinity ...
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The Upper Central Series of the Unit Groups of Integral Group Rings: A Survey

, 2018
Sugandha Maheshwary, I. Passi
semanticscholar   +1 more source

Brain and other central nervous system tumor statistics, 2021

Ca-A Cancer Journal for Clinicians, 2021
Kimberly D Miller, Quinn T Ostrom, Carol Kruchko Ba   +2 more
exaly  

Central England and De Bilt Series

1981
Two of the longest instrumental records of temperature existing in the world, are the Central England (1659-present) and the De Bilt, The Netherlands (1735-present) series. In this paper, a comparative description of the series is given. Due to the small distance between England and The Netherlands, the series are strongly correlated, which makes it ...
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