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1.
In this paper, we establish the generalized Hyers–Ulam–Rassias stability of C*-ternary ring homomorphisms associated to the Trif functional equation
  相似文献   

2.
Let X and Y be vector spaces. The authors show that a mapping f : X →Y satisfies the functional equation 2d f(∑^2d j=1(-1)^j+1xj/2d)=∑^2dj=1(-1)^j+1f(xj) with f(0) = 0 if and only if the mapping f : X→ Y is Cauchy additive, and prove the stability of the functional equation (≠) in Banach modules over a unital C^*-algebra, and in Poisson Banach modules over a unital Poisson C*-algebra. Let A and B be unital C^*-algebras, Poisson C^*-algebras or Poisson JC^*- algebras. As an application, the authors show that every almost homomorphism h : A →B of A into is a homomorphism when h((2d-1)^nuy) =- h((2d-1)^nu)h(y) or h((2d-1)^nuoy) = h((2d-1)^nu)oh(y) for all unitaries u ∈A, all y ∈ A, n = 0, 1, 2,.... Moreover, the authors prove the stability of homomorphisms in C^*-algebras, Poisson C^*-algebras or Poisson JC^*-algebras.  相似文献   

3.
Let n≥2 be an integer number. In this paper, we investigate the generalized Hyers Ulam- Rassias stability in Banach spaces and also Banach modules over a Banach algebra and a C*-algebra and the stability using the alternative fixed point of an n-dimensional cubic functional equation in Banach spaces:f(2∑j=1^n-1 xj+xn)+f(2∑j=1^n-1 xj-xn)+4∑j=1^n-1f(xj)=16f(∑j=1^n-1 xj)+2∑j=1^n-1(f(xj+xn)+f(xj-xn)  相似文献   

4.
In this article, we study an iterative procedure of the following form
, where f is a function and F is a set valued map acting from a Banach space X to a linear normed space Y, for solving generalized equations. We show that this method is locally Q-linearly convergent to a solution x* of the generalized equation
if the set-valued map
is Aubin continuous at (0, x*) with a constant M for growth, f: XY is a function, whose Fréchet derivative is L-Lipschitz and AL(X,Y) is such that 2M∥Δf(x*) − A∥ < 1. We also study the stability of this method. The research of this paper is partially supported by a Technical University of Varna internal research grant number 487/2008.  相似文献   

5.
This paper is a survey on the Hyers–Ulam–Rassias stability of the following Cauchy–Jensen functional equation in C *-algebras:
The concept of Hyers–Ulam–Rassias stability originated from the Th.M. Rassias’ stability theorem (Rassias in Proc. Am. Math. Soc. 72:297–300, [1978]). This work was supported by the research fund of Hanyang University (HY-2007-S).  相似文献   

6.
Let X and Y be vector spaces. It is shown that a mapping f : XY satisfies the functional equation
(‡)
if and only if the mapping f : XY is additive, and prove the Cauchy–Rassias stability of the functional equation (‡) in Banach modules over a unital C*-algebra. Let and be unital C*-algebras, Poisson C*-algebras, Poisson JC*-algebras or Lie JC*-algebras. As an application, we show that every almost homomorphism h : → of into is a homomorphism when h((d + 2)nuy) = h((d + 2)nu)h(y) or h((d + 2)nuy) = h((d + 2)nu) ∘ h(y) for all unitaries u ∈ , all y ∈ , and n = 0, 1, 2, • • • . Moreover, we prove the Cauchy–Rassias stability of homomorphisms in C*-algebras, Poisson C*-algebras, Poisson JC*-algebras or Lie JC*-algebras. Supported by Korea Research Foundation Grant KRF-2004-041-C00023.  相似文献   

7.
In this paper, a nonlinear difference system {xn=βxn-1+f(yn-κ),yn=βyn-1+f(xn-κ),n∈N is considered a,nd sufficient conditions for the existe~lce of the stable 2κ + 1 periodic solution are obtained.  相似文献   

8.
Letf(X) be an additive form defined by
wherea i ≠0 is integer,i=1,2…,s. In 1979, Schmidt proved that if ∈>0 then there is a large constantC(k,∈) such that fors>C(k,∈) the equationf(X)=0 has a nontrivial, integer solution in σ1, σ2, …, σ3,x 1,x 2, …,x 3 satisfying
Schmidt did not estimate this constantC(k,∈) since it would be extremely large. In this paper, we prove the following result  相似文献   

9.
Let Δ(x) denote the error term in the Dirichlet divisor problem, and E(T) the error term in the asymptotic formula for the mean square of . If E *(t)=E(t)-2πΔ*(t/2π) with , then we obtain
and
It is also shown how bounds for moments of | E *(t)| lead to bounds for moments of .  相似文献   

10.
Let X, Y be vector spaces. It is shown that if a mapping f : X → Y satisfies f((x+y)/2+z)+f((x-y)/2+z=f(x)+2f(z),(0.1) f((x+y)/2+z)-f((x-y)/2+z)f(y),(0.2) or 2f((x+y)/2+x)=f(x)+f(y)+2f(z)(0.3)for all x, y, z ∈ X, then the mapping f : X →Y is Cauchy additive. Furthermore, we prove the Cauchy-Rassias stability of the functional equations (0.1), (0.2) and (0.3) in Banach spaces. The results are applied to investigate isomorphisms between unital Banach algebras.  相似文献   

11.
In this article, the operator is introduced and named as the Bessel diamond operator iteratedk times and is defined by
where ,i = 1, 2, ...,n k is a non-negative integer andn is the dimension of ℝ n + . In this work we study the elementary solution of the Bessel diamond operator and the elementary solution of the operator is called the Bessel diamond kernel of Riesz. Then, we study the Fourier-Bessel transform of the elementary solution and also the Fourier-Bessel transform of their convolution.  相似文献   

12.
Suppose that X is a complex Banach space with the norm ‖·‖ and n is a positive integer with dim Xn ⩾ 2. In this paper, we consider the generalized Roper-Suffridge extension operator $ \Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f) $ \Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f) on the domain $ \Omega _{p_1 ,p_2 , \ldots ,p_{n + 1} } $ \Omega _{p_1 ,p_2 , \ldots ,p_{n + 1} } defined by
$ \Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)(x) = {*{20}c} {\sum\limits_{j = 1}^n {\left( {\frac{{f(x_1^* (x))}} {{x_1^* (x)}}} \right)} ^{\beta _j } (f'(x_1^* (x)))^{\gamma _j } x_1^* (x)x_j } \\ { + \left( {\frac{{f(x_1^* (x))}} {{x_1^* (x)}}} \right)^{\beta _{n + 1} } (f'(x_1^* (x)))^{\gamma _{n + 1} } \left( {x - \sum\limits_{j = 1}^n {x_1^* (x)x_j } } \right)} \\ $ \Phi _{n,\beta _2 ,\gamma _2 , \ldots ,\beta _{n + 1} ,\gamma _{n + 1} } (f)(x) = \begin{array}{*{20}c} {\sum\limits_{j = 1}^n {\left( {\frac{{f(x_1^* (x))}} {{x_1^* (x)}}} \right)} ^{\beta _j } (f'(x_1^* (x)))^{\gamma _j } x_1^* (x)x_j } \\ { + \left( {\frac{{f(x_1^* (x))}} {{x_1^* (x)}}} \right)^{\beta _{n + 1} } (f'(x_1^* (x)))^{\gamma _{n + 1} } \left( {x - \sum\limits_{j = 1}^n {x_1^* (x)x_j } } \right)} \\ \end{array}   相似文献   

13.
In this paper we apply the method of potentials for studying the Dirichlet and Neumann boundary-value problems for a B-elliptic equation in the form
$ \Delta _{x'} u + B_{x_{p - 1} } u + x_p^{ - \alpha } \frac{\partial } {{\partial x_p }}\left( {x_p^\alpha \frac{{\partial u}} {{\partial x_p }}} \right) = 0 $ \Delta _{x'} u + B_{x_{p - 1} } u + x_p^{ - \alpha } \frac{\partial } {{\partial x_p }}\left( {x_p^\alpha \frac{{\partial u}} {{\partial x_p }}} \right) = 0   相似文献   

14.
In this paper, we will find out the general solution and investigate the generalized Hyers-Ulam-Rassias stability problem for the following cubic functional equation
2f(x + 2y) + f(2x - y) = 5f(x + y) + 5f(x - y)+ 15f(y)
in the spirit of Hyers, Ulam, Rassias and Gavruta.  相似文献   

15.
Letr, s ∈ [0, 1], and letX be a Banach space satisfying theM(r, s)-inequality, that is,
where π X is the canonical projection fromX *** ontoX *. We show some examples of Banach spaces not containingc 0, having the point of continuity property and satisfying the above inequality forr not necessarily equal to one. On the other hand, we prove that a Banach spaceX satisfying the above inequality fors=1 admits an equivalent locally uniformly rotund norm whose dual norm is also locally uniformly rotund. If, in addition,X satisfies
wheneveru *,v *X * with ‖u *‖≤‖v *‖ and (x α * ) is a bounded weak* null net inX *, thenX can be renormed to satisfy the,M(r, 1) and theM(1, s)-inequality such thatX * has the weak* asymptotic-norming property I with respect toB X .  相似文献   

16.
We study the vector p-Laplacian
We prove that there exists a sequence (u n ) of solutions of (*) such that u n is a critical point of ϕ and another sequence (u n * ) of solutions of (*) such that u n * is a local minimum point of ϕ, where ϕ is a functional defined below. The research is supported by NNSF of China (10301033).  相似文献   

17.
In the paper we study a binding boundary value problem for two media for Poisson's equation μΔu=f(x) with solutions in the class , 1<p<∞, with the corresponding seminorm, where
It is proved that the solution exists for allf(x)L p , anda priori estimates of the solution are obtained with the help of multiplicators in the space . An explicit solution of the problem for all is obtained. The kernel of the operator generated by the problem is constructed (in explicit form) as a polynomial of the first degree. Translated fromMatematicheskie Zametki, Vol. 66, No. 4, pp. 515–526, October, 1999.  相似文献   

18.
For functions satisfying the boundary conditions
, the following inequality with sharp constants in additive form is proved:
wheren≥2, 0≤1≤n−2,−1≤m≤1, m+1≤n−3, and1≤p,q,r≤∞. Translated fromMatematicheskie Zametki, Vol. 62, No. 5, pp. 712–724, November, 1997. Translated by N. K. Kulman  相似文献   

19.
Some new oscillation criteria for nonlinear delay difference equation with damping △^2xn+pn△xn+F(n,x(n-τ,△x(n-σ)=0,n=0,1,2,…,(*)are given. Our results partially solve the open problem posed in [Math. Bohemica, 125 (2000), 421- 430]. Also, we will establish some new oscillation criteria for special cases of (*), which improve some of the well-known results in the literature.  相似文献   

20.
Let Z/(pe) be the integer residue ring modulo pe with p an odd prime and integer e ≥ 3. For a sequence (a) over Z/(pe), there is a unique p-adic decomposition (a) = (a)0 (a)1·p … (a)e-1 ·pe-1, where each (a)i can be regarded as a sequence over Z/(p), 0 ≤ i ≤ e - 1. Let f(x) be a primitive polynomial over Z/(pe) and G' (f(x), pe) the set of all primitive sequences generated by f(x) over Z/(pe). For μ(x) ∈ Z/(p)[x] with deg(μ(x)) ≥ 2 and gcd(1 deg(μ(x)),p- 1) = 1,set ψe-1 (x0, x1,…, xe-1) = xe-1·[ μ(xe-2) ηe-3 (x0, x1,…, xe-3)] ηe-2 (x0, x1,…, xe-2),which is a function of e variables over Z/(p). Then the compressing map ψe-1: G'(f(x),pe) → (Z/(p))∞,(a) (→)ψe-1((a)0, (a)1,… ,(a)e-1) is injective. That is, for (a), (b) ∈ G' (f(x), pe), (a) = (b) if and only if ψe - 1 ((a)0, (a)1,… , (a)e - 1) =ψe - 1 ((b)0,(b)1,… ,(b)e-1). As for the case of e = 2, similar result is also given. Furthermore, if functions ψe-1 and ψe-1 over Z/(p) are both of the above form and satisfy ψe-1((a)0,(a)1,… ,(a)e-1) = ψe-1((b)0,(b)1,… ,(b)e-1) for (a),(b) ∈ G'(f(x),pe), the relations between (a) and (b), ψe-1 and ψe-1 are discussed.  相似文献   

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