${[\ell_p]}_{e.r}$ Euler-Riesz Difference Sequence Spaces

Başar and Braha [1], introduced the sequence spaces $\breve{\ell}_\infty$, $\breve{c}$ and $\breve{c}_0$ of Euler-Cesáro bounded, convergent and null difference sequences and studied their some properties. Then, in [2], we introduced the sequence spaces ${[\ell_\infty]}_{e.r}, {[c]}_{e.r}$ and ${[c_0]}_{e.r}$ of Euler-Riesz bounded, convergent and null difference sequences by using the composition of the Euler mean $E_1$ and Riesz mean $R_q$ with backward difference operator $\Delta$. The main purpose of this study is to introduce the sequence space ${[\ell_p]}_{e.r}$ of Euler-Riesz $p-$absolutely convergent series, where $1 \leq p <\infty$, difference sequences by using the composition of the Euler mean $E_1$ and Riesz mean $R_q$ with backward difference operator $\Delta$. Furthermore, the inclusion $\ell_p\subset{[\ell_p]}_{e.r}$ hold, the basis of the sequence space ${[\ell_p]}_{e.r}$ is constructed and $\alpha-$, $\beta-$ and $\gamma-$duals of the space are determined. Finally, the classes of matrix transformations from the ${[\ell_p]}_{e.r}$ Euler-Riesz difference sequence space to the spaces $\ell_\infty, c$ and $c_0$ are characterized. We devote the final section of the paper to examine some geometric properties of the space ${[\ell_p]}_{e.r}$.     

On the duality theorem of bounded S-decomposable operators

A class of linear operators, more general than that of the decomposable operators, here referred to as S-decomposable operators, was introduced in [10]. It was shown in [11] that the dual of an S-decomposable operator was again S-decomposable. Our main result, in this paper, is the converse implication, namely, if the dual $\text{T1}$ of a bounded linear operator T is S-decomposable then T is S-decomposable.     

Fast Parallel Algorithms for Computing Generalized Inverses $A^+$ and $A_{MN}^+$

The parallel arithmetic complexities for computing generalized inverse $A^+$, computing the minimum-norm least-squares solution of $Ax=b$, computing order $m+n-r$ determinants and finding the characteristic polynomials of order $m+n-r$ matrices are shown to have the same grawth rate. Algorithms are given that compute $A^+$ and $A_{MN}^+$ in $O(\log r\dot \log n+\log m)$ and $O(\log^2n+\log m)$ steps using a number of processors which is a polynomial in $m, \ n$ and $r$ $(A\in B_r^{m\times n},r=rank \ A)$.     

Nonlinear Mixed Jordan Triple $ * $ -Derivations on $ * $ -Algebras

Siberian Mathematical Journal - Let $ {\mathcal{A}} $ be a&nbsp;unital $ \ast $ -algebra containing a&nbsp;nontrivial projection. Under some mild conditions on&nbsp; $ {\mathcal{A}} $ ,...     

The Dirichlet energy of mappings from ${\bf B^3}$ into a manifold: density results and gap phenomenon

Weak limits of graphs of smooth maps with equibounded Dirichlet integral give rise to elements of the space . We assume that the 2-homology group of has no torsion and that the Hurewicz homomorphism is injective. Then, in dimension n = 3, we prove that every element T in , which has no singular vertical part, can be approximated weakly in the sense of currents by a sequence of smooth graphs {u _k } with Dirichlet energies converging to the energy of T. We also show that the injectivity hypothesis on the Hurewicz map cannot be removed. We finally show that a similar topological obstruction on the target manifold holds for the approximation problem of the area functional.Received: 9 May 2003, Accepted: 5 June 2003, Published online: 25 February 2004     

IdeallyF-decomposable semigroups

We consider ideallyy -decomposable semigroups (y — is a system of semigroup identities). It is proved that every ideallyy -decomposable semigroup has ay -decomposable series of ideals.Translated from Matematicheskie Zametki, Vol. 8, No, 6, pp. 681–691, December, 1970.     

An $L_1$ Minimization Problem by Generalized Rational Functions

Let $P,Q \subset L_1(X,\Sigma,\mu)$ and $q(x)>0$ a. e. in $X$ for all $q\in Q$. Define $R=\{p/q:p\in P,q\in Q\}$. In this paper we discuss an $L_1$ minimization problem of a nonnegative function $E(z,x)$, i.e. we wish to find a minimum of the functional $\phi(r)=\int _X qE(r,x)d\mu$ form $r=p/q\in R$. For such a problem we have established the complete characterizations of its minimum and of uniqueness of its minimum, when both $P,Q$ are arbitrary convex subsets.     

3$\times$3阶上三角型算子矩阵的可能谱

Let H1, H2 and H3 be infinite dimensional separable complex Hilbert spaces. We denote by M（D,V,F） a 3×3 upper triangular operator matrix acting on Hi ＋H2＋ H3 of theform M（D,E,F）=（A D F 0 B F 0 0 C）.For given A ∈ B（H1）, B ∈ B（H2） and C ∈ B（H3）, the sets ∪D,E,F^σp（M（D,E,F））,∪D,E,F ^σr（M（D,E,F））,∪D,E,F ^σc（M（D,E,F）） and ∪D,E,F σ（M（D,E,F）） are characterized, where D ∈ B（H2,H1）, E ∈B（H3, H1）, F ∈ B（H3,H2） and σ（·）, σp（·）, σr（·）, σc（·） denote the spectrum, the point spectrum, the residual spectrum and the continuous spectrum, respectively.     

由圈长分布确定的二部图~$K_{n,n r}-A\ (|A|\leq 3)$

The cycle length distribution of a graph G of order n is a sequence （c1 （G）,…, cn （G））, where ci （G） is the number of cycles of length i in G. In general, the graphs with cycle length distribution （c1（G） ,…,cn（G）） are not unique. A graph G is determined by its cycle length distribution if the graph with cycle length distribution （c1 （G）,…, cn （G）） is unique. Let Kn,n＋r be a complete bipartite graph and A lohtaib in E（Kn,n＋r）. In this paper, we obtain： Let s 〉 1 be an integer. （1） If r = 2s, n 〉 s（s - 1） ＋ 2｜A｜, then Kn,n＋r - A （A lohtain in E（Kn,n＋r）,｜A｜ ≤ 3） is determined by its cycle length distribution; （2） If r = 2s ＋ 1,n 〉 s^2 ＋ 2｜A｜, Kn,n＋r - A （A lohtain in E（Kn,n＋r）, ｜A｜ ≤3） is determined by its cycle length distribution.     

A New Characterization of Finite $ \sigma $ -Soluble $ P\sigma T $ -Groups

Siberian Mathematical Journal - We prove that&nbsp; $ G $ is a finite $ \sigma $ -soluble group with transitive $ \sigma $ -permutability if and only if the following hold: (i) $ G $ possesses...     

High dimensional reducible hyperplane sections with multigenera $\leq$ 1

Let X be an algebraic submanifold of the complex projective space $\mathbb{P}^N$ of dimension $n \geq 5$. We describe those $X \subset \mathbb{P}^N$ whose intersection with some hyperplane is a smooth simply normal crossing divisor $A_{1} + \cdots + A_{r}$ with $r \geq 2$ such that $g(A_{k}, L_{A_k}) \leq 1$ for $k=1,\ldots, r$.Received: 14 December 2001     

$C(X)$上的开点与紧开拓扑

In this note we define a new topology on C(X),the set of all real-valued continuous functions on a Tychonoff space X.The new topology on C(X) is the topology having subbase open sets of both kinds:[f,C,ε[={g E C(X):|f(x)-g(x)| ε for every x∈C} and[U,r]~-={g∈C(X):g~(-1)(r)∩U≠φ},where f∈C(X),C∈KC(X)={nonempty compact subsets of X},ε 0,while U is an open subset of X and r∈R.The space C(X) equipped with the new topology T_(kh) which is stated above is denoted by C_(kh)(X).Denote X_0={x∈X:x is an isolated point of X} and X_c={x∈X:x has a compact neighborhood in X}.We show that if X is a Tychonoff space such that X_0=X_c,then the following statements are equivalent:(1) X_0 is G_δ-dense in X;(2) C_(kh)(X) is regular;(3) C_(kh)(X) is Tychonoff;(4) C_(kh)(X) is a topological group.We also show that if X is a Tychonoff space such that X_0=X_c and C_(kh)(X) is regular space with countable pseudocharacter,then X is σ-compact.If X is a metrizable hemicompact countable space,then C_(kh)(X) is first countable.     

Generalized Rickart $ \ast $ -Rings

Siberian Mathematical Journal - As a common generalization of Rickart $ \ast $ -rings and generalized Baer $ \ast $ -rings, we say that a&nbsp;ring&nbsp; $ R $ with an involution&nbsp;...     

Beyond sparsity: Recovering structured representations by ${\ell}^1$ minimization and greedy algorithms

Finding a sparse approximation of a signal from an arbitrary dictionary is a very useful tool to solve many problems in signal processing. Several algorithms, such as Basis Pursuit (BP) and Matching Pursuits (MP, also known as greedy algorithms), have been introduced to compute sparse approximations of signals, but such algorithms a priori only provide sub-optimal solutions. In general, it is difficult to estimate how close a computed solution is from the optimal one. In a series of recent results, several authors have shown that both BP and MP can successfully recover a sparse representation of a signal provided that it is sparse enough, that is to say if its support (which indicates where are located the nonzero coefficients) is of sufficiently small size. In this paper we define identifiable structures that support signals that can be recovered exactly by minimization (Basis Pursuit) and greedy algorithms. In other words, if the support of a representation belongs to an identifiable structure, then the representation will be recovered by BP and MP. In addition, we obtain that if the output of an arbitrary decomposition algorithm is supported on an identifiable structure, then one can be sure that the representation is optimal within the class of signals supported by the structure. As an application of the theoretical results, we give a detailed study of a family of multichannel dictionaries with a special structure (corresponding to the representation problem ) often used in, e.g., under-determined source sepa-ration problems or in multichannel signal processing. An identifiable structure for such dictionaries is defined using a generalization of Tropp’s Babel function which combines the coherence of the mixing matrix with that of the time-domain dictionary , and we obtain explicit structure conditions which ensure that both minimization and a multi-channel variant of Matching Pursuit can recover structured multichannel representations. The multichannel Matching Pursuit algorithm is described in detail and we conclude with a discussion of some implications of our results in terms of blind source separation based on sparse decompositions. Communicated by Yuesheng Xu     

对谱半径至多为$\sqrt[r]{2+\sqrt{5}}$的超图的分类研究

在本文,我们研究谱半径至多为$\sqrt[r]{2+\sqrt{5}}$的超图.我们得到此种超图必须具有一个基普结构,这与Woo-Neumaier在2007年对谱半径至多为$\frac{3}{2}\sqrt{2}$的图的分类结果类似.     

Almost $ \omega $ -Categorical Weakly $ o $ -Minimal Theories of Convexity Rank 1

Siberian Mathematical Journal - Studying the properties of almost $ \omega $ -categorical weakly $ o $ -minimal theories of convexity rank&nbsp;1, we prove the orthogonality of every family of...     

On finite groups with p-decomposable cofactors of subgroups

It is proved that, for a finite group with p-decomposable cofactors of the maximal subgroups, the quotient group by the Fitting subgroup is p-decomposable. This implies that every group all of whose maximal subgroups have nilpotent cofactors is metanilpotent.     

Operator-semistable,operator semi-selfdecomposable probability measures and related nested classes on <Emphasis Type="Italic">p</Emphasis>-adic vector spaces

Let V be a finite dimensional p-adic vector space and let τ be an operator in GL(V). A probability measure μ on V is called τ-decomposable or if μ = τ(μ)* ρ for some probability measure ρ on V. Moreover, when τ is contracting, if ρ is infinitely divisible, so is μ, and if ρ is embeddable, so is μ. These two subclasses of are denoted by L ₀(τ) and L ₀ ^#(τ) respectively. When μ is infinitely divisible τ-decomposable for a contracting τ and has no idempotent factors, then it is τ-semi-selfdecomposable or operator semi-selfdecomposable. In this paper, sequences of decreasing subclasses of the above mentioned three classes, , are introduced and several properties and characterizations are studied. The results obtained here are p-adic vector space versions of those given for probability measures on Euclidean spaces.     

亚纯函数微分多项式f^kQ[f]+P[f]的零点分布

研究了超越亚纯函数$f$的微分多项式$f^kQ[f]+P[f]$的零点分布. 给出了以下结果:对于满足$\delta(\infty,f)\geq1-\alpha>0$ ($\alpha$为常数, $0\leq \alpha<1$ )的超越亚纯函数$f(z)$, 若$T(r,f)=O((\log r)^2)$,则微分多项式$f^kQ[f]+P[f]$ ($Q[f]\not\equiv 0,\ P[f] \not\equiv 0$)在 可数个圆盘并集之外有无穷多个零点,其中$k>\frac{1+\Gamma_{P}+\gamma_{P}+\alpha(1+\Gamma_Q+\Gamma_{P}-\gamma_{P})} {1-\alpha }$, $\Gamma_{Q}$是$Q[f]$的权, $\Gamma_{P}$和$\gamma_{P}$是$P[f]$的权和次数.     

Central Isotopes of $ (-1,1) $ -Algebras

Siberian Mathematical Journal - We prove that each $ c $ -isotope of a prime nonassociative $ (-1,1) $ -algebra is a $ (-1,1) $ -algebra if and only if the element&nbsp; $ c $ lies in the...