Bohr Inequality for Multiple Op erators

An absolute value equation is established for linear combinations of two operators. When the parameters take special values, the parallelogram law of operator type is given. In addition, the operator equation in literature [3] and its equivalent deformation are obtained. Based on the equivalent deformation of the operator equation and using the properties of conjugate number as well as the operator, an absolute value identity of multiple operators is given by means of mathematical induction. As Corollaries, Bohr inequalities are extended to multiple operators and some related inequalities are reduced to, such as inequalities in [2] and [3].     

闭算子Moore-Penrose逆的逆序律(英文)

In this paper, the reverse order law for the Moore-Penrose inverse of closed linear operators with closed range is investigated by virtue of the Norm-preserving extension of the bounded linear operators. The results generalize some results obtained by S Izumino in [12].     

PROBABILISTIC APPROACH TO SEMILINEAR AND GENERALIZED MIXED BOUNDARY VALUE PROBLEMS

A probabilistic approach is developed to solve semilinear and generalized mixed boundaryvalue problems involving Schrodinger operators. The results obtained in this paper generalize thecorresponding results of [1] and partly generalize the result of [2] as well.     

A NOTE ON H-w~p-BOUNDEDNESS OF RIESZ TRANSFORMS AND θ-CALDERóN-ZYGMUND OPERATORS THROUGH MOLECULAR CHARACTERIZATION

Let 0 p ≤ 1 and w in the Muckenhoupt class A1. Recently, by using the weighted atomic decomposition and molecular characterization, Lee, Lin and Yang[11] es- tablished that the Riesz transforms Rj, j = 1,2,··· ,n, are bounded on Hwp(Rn). In this note we extend this to the general case of weight w in the Muckenhoupt class A∞ through molec- ular characterization. One difficulty, which has not been taken care in [11], consists in passing from atoms to all functions in Hwp(Rn). Furthermore, the Hwp-boundedness of θ- Calderón-Zygmund operators are also given through molecular characterization and atomic decomposition.     

EXISTENCE OF POSITIVE PERIODIC SOLUTION OF MUTUALISM SYSTEM WITH INFINITE DELAYS

In this paper, by using Mawhin coincidence degree, some sufficient conditions are obtained for the global existence of positive periodic solution of a mutualism system with infinite delays. Our results generalize those of Yang etc. [8] and Gopalsamy and He [7].     

ON THE RATE OF CONVERGENCE OF BEZIER VARIANT OF SZASZ—DURRMEYER OPERATORS

In the present paper, we introduce Szasz-Durrmeyer-Bezier operators M.,.(f,x) , which generalize the Szasz-Durrmeyer operators. Here we obtain an estimate on the rate of convergence of Mn,a(f,x) for functions of bounded variation. Our result extends and improves that of Sahai and Prasad and Gupta and Pant.     

Approximation by Szasz-Mirakjan Type Operators in L''''

M.M.Derriennic discussed the properties of Bernstein-Durrmeyer operators,M. Heilmann solved the saturation situation and the author obtained the characte-rization of their order of approximation.As extending Kantorovich polynomials inL_p[0,1]to Szász-Mirakjan-Kantorovich operators in L_p[0,∞)by V.Totik,We in-troduce a new class of Szász-Mirakjan type operators:     

SOME TWO-INDEPENDENT-VARIABLE INEQUALITIES INVOLVING IMPROPER INTEGRALS

In the paper the authors establish four theorems on two-independent-variableGronwall-type inequalities involving improper integrals with infinite integration limits.The results obtained improve and generalize the main results proved in the recent paper[5] by A.Corduneanu.Two classes of nonlinear continuous functions defined by F.M.Dannan[6] are applied in this article.And the results can be used as handy tools in thestudy of many Volterra integral and integro-differential equations with improper integralfunctionals.     

BLOW-UP OF THE SOLUTION FOR A KIND OF HIGHER ORDER HYPERBOLIC EVOLUTION SYSTEMS

In this paper, we give some results on the blow-up behaviors of the solution to the mixed problem for some higher nonlinear hyperbolic evolution equation in finite time. By introducing the "blow-up factor K(u,ut)" we get some new results, which generalize the conclusions of [3] and [4].     

THE EXISTENCE OF ALMOST PERIODIC SOLUTION TO A CLASS OF ALMOST PERIODIC DIFFERENTIAL SYSTEM

By means of the fixed point theorem and exponential dichotomy, in this paper we investigate the existence of almost periodic solutions to a class of n-dimensional almost periodic systems, which is more general than the systems in [1-2]. We generalize and improve some results in [3].     

CONVERGENCE OF A CLASS OF MEANS OF H~p FUNCTIONS(0

《分析论及其应用》1993,(4)

The closures of (U+K)-orbits of essentially normal triangular operator models

The (U + K)-orbit of a bounded linear operator T acting on a Hilbert space H is defined as (U + K)(T)={R-1 T R:R is invertible of the form unitary plus compact on H}.In this paper,we first characterize the closure of the (U + K)-orbit of an essentially normal triangular operator T satisfying H={ker(T-λI):λ∈ρ F (T)} and σ p (T*)=ф.After that,we establish certain essentially normal triangular operator models with the form of the direct sums of triangular operators,adjoint of triangular operators and normal operators,show that such operator models generate the same closed (U + K)-orbit if they have the same spectral picture,and describe the closures of the (U + K)-orbits of these operator models.These generalize some known results on the closures of (U + K)-orbits of essentially normal operators,and provide more positive cases to an open conjecture raised by Marcoux as Question 2 in his article "A survey of (U + K)-orbits".     

Fibrations and stability for compact group actions on manifolds with local bounded Ricci covering geometry

In the study of the collapsed manifolds with bounded sectional curvature,the following two results provide basic tools:a(singular)fibration theorem by K.Fukaya[J.Differential Gcom.,1987.25(1):139156]and J.Cheeger,K.Fukaya,and M.Gromov[J.Airier.Math.Soc.,1992.5(2):327372],and the stability for isometric compact Lie group actions on manifolds by R.S.Palais[Bull.Amer.Math.Soc.,1961,67(4):362364]and K.Grove and H.Karcher[Math.Z..1973,132:1120].The main results in this paper(partially)generalize the two results to manifolds with local bounded Ricci covering geometry.     

COHERENT STATES, INVERSE MAPPING FORMULA FOR WEYL TRANSFORMATIONS AND APPLICATION TO EQUATIONS OF KdV TYPE

In this paper, we consider the trace of generalized operators and inverse Weyl transformation.First of all we repeat the definition of test operators and generalized operators given in [18],denoting L~2(R) by H.     

Direct and Inverse Results for Combinations and Derivatives of Bernstein Operators

The author is supported by the Zhejiang Provincial Natural Sciences Foundation of China.For the Bernstein operators, M. Felten[l] gave the direct and inverse estimates by theDitzian-Totik modulus of smoothness w~2(f, t), whereby the step-weight. is a function as suchthat is concave for the direct estimate and . are concavefor the inverse estimate. For the combinations of the Bernstein operators, D. X. Zhou[2] gavethe direct and inverse estimates by the classical modulus of smoothness wit…     

Simultaneous Approximation for Szsz-Mirakian-Stancu-Durrmeyer Operators

The aim of this work is to generalize Szsz-Mirakian operator in the sense of Stancu-Durrmeyer operators. We obtain approximation properties of these operators. Here we study asymptotic as well as rate of convergence results in simultaneous approximation for these modified operators.     

THE DECOMPOSITION OF STATE SPACE FOR MARKOV CHAIN IN RANDOM ENVIRONMENT

This paper is a continuation of [8] and [9]. The author obtains the decomposition of state space X of an Markov chain in random environment by making use of the results in [8] and [9], gives three examples, random walk in random environment, renewal process in random environment and queue process in random environment, and obtains the decompositions of the state spaces of these three special examples.     

The Second Moments for the Meyer-Knig and Zeller Operators on the Simplex

The moments for positive linear operators, in particular the second order's, is an interest topic in theory of approximation. In 1984, Alkemade[1] succeed in deriving an explicit expression of the second moment in terms of a hypergeometric series for the Meyer-Konig and Zeller opera-tors. Later in 1995, Abel[2] extend it to arbitrary order. The Meyer-Konig and Zeller operators in slight modification of Cheney and Sharma[3] are defined as followswhereDenoting by er the function x →xr (r = …     

THE REAL HYPER-ELLIPTIC SUBSPACES OF TEICHMüLLER SPACE AND MODULI SPACE

Although the existence and uniqueness of Strebel differentials are proved by Jenkins and Strebel, the specific constructions of Strebel differentials are difficult. Two special kinds of special Strebel differentials are constructed in [5, 6]. The Strebel rays [3] and the eventually distance minimizing rays [9] are important in Teichm¨uller spaces and moduli spaces, respectively. Motivated by the study of [3, 9], two special kinds of Strebel rays in the real hyper-elliptic subspace of Teichm¨uller space and two special kinds of EDM rays in the real hyper-elliptic subspace of moduli space are studied in this article.     

关于《具有缺项和负系数的多叶函数》一文的注记

In this note we shall use the same notations and terms as ones in[1,3].Very recently,Sarangi and Patil[1]if considered the subclass P_k(p,A,B)of analyticp-valent functions with negative and missing coefficients and proved seven theorems con-cerning the class P_k(p,A,B).Theorems1,2,3,5,6 and7 of[l]generalize the correspondingresults obtained by Goel and Sohi[2]from k=1 to k≥2.However,it is easy to see thatsuch a generalization is trivial and simple.