共查询到20条相似文献,搜索用时 15 毫秒
1.
Xinjian Zhang 《代数通讯》2017,45(11):4971-4973
In this paper, we studied the supersolvability of the product of two subgroups and got a generalization of Baer’s theorem. 相似文献
2.
Sandro Bettin Jonathan W. Bober Andrew R. Booker Brian Conrey Min Lee Giuseppe Molteni Thomas Oliver David J. Platt Raphael S. Steiner 《The Ramanujan Journal》2018,45(3):659-681
By using specific subsequences of two different types of generalized Stern polynomials, we obtain several related classes of finite and infinite continued fractions involving a single term \(z^{t^j}\) in their partial numerators, where z is a complex variable and t is a positive integer. This approach is extended to other, sparser, subsequences of Stern polynomials, based on certain Lucas functions; this then leads to further infinite classes of continued fractions. 相似文献
3.
Peyman Niroomand 《Archiv der Mathematik》2010,94(5):401-403
Schur’s theorem states that for a group G finiteness of G/Z(G) implies the finiteness of G′. In this paper, we show the converse is true provided that G/Z(G) is finitely generated and in such case, we have |G/Z(G)| ≤ |G′|
d(G/Z(G)). In the special case of G being nilpotent, we prove |G/Z(G)| divides |G′|
d(G/Z(G)). 相似文献
4.
B. Sury 《Archiv der Mathematik》2010,95(4):317-318
Niroomand (Arch. Math. 94 (2010) 401–404) proved a converse to a theorem of Schur in the following sense. He proved that if G is a group such that [G, G] is finite and G/Z(G) is finitely generated, then G/Z(G) is finite, of order bounded above by [G, G]
k
where k is the minimal number of generators required for G/Z(G). Here, we give a completely elementary short proof of a further generalization. 相似文献
5.
Molly Dunkum 《Czechoslovak Mathematical Journal》2009,59(1):241-247
There is a classical result known as Baer’s Lemma that states that an R-module E is injective if it is injective for R. This means that if a map from a submodule of R, that is, from a left ideal L of R to E can always be extended to R, then a map to E from a submodule A of any R-module B can be extended to B; in other words, E is injective. In this paper, we generalize this result to the category q
ω consisting of the representations of an infinite line quiver. This generalization of Baer’s Lemma is useful in proving that
torsion free covers exist for q
ω.
相似文献
6.
E. A. Lebedeva 《Mathematical Notes》2010,88(5-6):717-722
We study the asymptotic behavior of the roots of polynomials given by a linear summation method for partial sums of the Fourier series. 相似文献
7.
Nekhoroshev discovered a beautiful theorem in Hamiltonian systems that includes as special cases not only the Poincaré theorem on periodic orbits but also the theorem of Liouville–Arnol’d on completely integrable systems [7]. Sadly, his early death precluded him publishing a full account of his proof. The aim of this paper is twofold: first, to provide a complete proof of his original theorem and second a generalization to the noncommuting case. Our generalization of Nekhoroshev’s theorem to the nonabelian case subsumes aspects of the theory of noncommutative complete integrability as found in Mishchenko and Fomenko [5] and is similar to what Nekhoroshev’s theorem does in the abelian case. 相似文献
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In a complete Riemannian manifold (M, g) if the hessian of a real-valued function satisfies some suitable conditions, then it restricts the geometry of (M, g). In this paper we characterize all compact rank-one symmetric spaces as those Riemannian manifolds (M, g) admitting a real-valued functionu such that the hessian ofu has at most two eigenvalues ?u and $ - \frac{{u + 1}}{2}$ under some mild hypotheses on (M, g). This generalizes a well-known result of Obata which characterizes all round spheres. 相似文献
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The purpose of this paper is to present a generalization of Forelli’s theorem. In particular, we prove an all dimensional version of the two-dimensional theorem of Chirka (Kompleks. Anal. i Prilozh, 232–240, 2006) of 2005. 相似文献
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16.
Hans G. Kellerer 《Archiv der Mathematik》1999,72(3):206-213
Given a nonatomic finite-dimensional vector measure on a topological space, a criterion is established for obtaining its full range by considering open (or closed) sets only. 相似文献
17.
A new proof of a theorem by Gromov is given: for any positive C and any integer n greater than 1, there exists a function Δ
C,n
(δ) such that if the Gromov–Hausdorff distance between two complete Riemannian n-manifolds V and W is at most δ, their sectional curvaturcs |K
σ
| do not exceed C, and their injectivity radii are at least 1/C, than the Lipschitz distance between V and W is less than Δ
C,n
(δ), and Δ
C,n
(δ) → 0 as δ → 0. Bibliography: 6 titles. 相似文献
18.
We present a proof of Sklar’s Theorem that uses topological arguments, namely compactness (under the weak topology) of the class of copulas and some density properties of the class of distribution functions. 相似文献
19.
Let $X$ be a manifold. The classification of all equivariant bilinear maps between tensor density modules over $X$ has been investigated by Grozman (Funct Anal Appl 14(2):58–59, 1980), who has provided a full classification for those which are differential operators. Here we investigate the same question without the hypothesis that the maps are differential operators. In our paper, the geometric context is algebraic geometry and the manifold $X$ is the circle $\text{ Spec}\, \mathbb{C }[z,z^{-1}]$ . Our main motivation comes from the fact that such a classification is required to complete the proof of the main result of Iohara and Mathieu (Proc Lond Math Soc, 2012, in press). Indeed it requires to also include the case of deformations of tensor density modules. 相似文献
20.
Matthew P. Young 《Archiv der Mathematik》2010,95(6):539-548
We give a short proof of Levinson’s result that over 1/3 of the zeros of the Riemann zeta function are on the critical line. 相似文献