Results 61 to 70 of about 722 (111)

Approximate *-derivations and approximate quadratic *-derivations on C*-algebras

Journal of Inequalities and Applications, 2011
In this paper, we prove the stability of *-derivations and of quadratic *-derivations on Banach *-algebras. We moreover prove the superstability of *-derivations and of quadratic *-derivations on C*-algebras.
Park Choonkil, Jang Sun
doaj  

Generalized Polynomials on Semigroups

Annales Mathematicae Silesianae
This article has two main parts. In the first part we show that some of the basic theory of generalized polynomials on commutative semi-groups can be extended to all semigroups.
Ebanks Bruce
doaj   +1 more source

Linear Independence of a Finite Set of Dilations by a One-Parameter Matrix Lie Group

, 2012
Let $G=\{e^{tA}:t\in\mathbb{R}\}$ be a closed one-parameter subgroup of the general linear group of matrices of order $n$ acting on $\mathbb{R}^{n}$ by matrix-vector multiplications. We assume that all eigenvalues of $A$ are rationally related.
Ferrone, David, Oussa, Vignon
core   +1 more source

Transcendental operators acting on slice regular functions

Concrete Operators, 2022
The aim of this paper is to carry out an analysis of five trascendental operators acting on the space of slice regular functions, namely *-exponential, *-sine and *-cosine and their hyperbolic analogues. The first three of them were introduced by Colombo,
de Fabritiis Chiara
doaj   +1 more source

Some orthogonality equation with two functions

, 2017
The aim of this paper is to describe the solution .f;g/ of the equation hf .x/jf .y/i D hg.x/jyi ; x;y 2X; where f WX ! Y , gWX !X , X;Y are inner product spaces over the same field K 2 fR;Cg.
Radoslaw Lukasik
semanticscholar   +1 more source

Cosine and Sine Addition and Subtraction Law with an Automorphism

Annales Mathematicae Silesianae
Let S be a semigroup. Our main results are that we describe the complex-valued solutions of the following functional equations g(xσ(y))=g(x)g(y)+f(x)f(y),x,y∈S,f(xσ(y))=f(x)g(y)+f(y)g(x),x,y∈S,\matrix{ {g\left( {x\sigma \left( y \right)} \right) = g ...
Aserrar Youssef, Elqorachi Elhoucien
doaj   +1 more source

HYERS-ULAM STABILITY OF QUADRATIC FUNCTIONAL EQUATIONS ON DIVISIBLE SQUARE-SYMMETRIC GROUPOID

, 2017
Let (X, ⋄) be a divisible square-symmetric groupoid, and (Y, ∗, d) a complete metric divisible square-symmetric groupoid. In this paper, we obtain the Hyers-Ulam stability problem of functional inequality d(f(x⋄y)∗f(x⋄y), σ∗(f(x)∗f(y))) ≤ ε(x, y) for ...
G. H. Kim, H.-Y. Shin
semanticscholar   +1 more source

On the Hyers-Ulam stability of approximately Pexider mappings

, 2008
In this paper we investigate the Hyers-Ulam stability of the Pexider functional equation f 1(x + y) + f 2(x + σ(y)) = f 3(x) + f 4(y), x, y ∈ E, where E is a normed space and σ : E −→ E is an involution.
B. Belaid, E. Elhoucien, T. Rassias
semanticscholar   +1 more source

On the Stability of Functional Equations with Square-Symmetric Operation

, 2001
In this paper, we obtain the modified Hyers-Ulam-Rassias stability for the family of functional equations f (x ◦ y) = H(f (x), f (y)) (x, y ∈ S) , where H is a homogeneous function and ◦ is a square-symmetric operation on the set S .
G. Kim
semanticscholar   +1 more source

On the stability of pexider functional equation in non-archimedean spaces

Journal of Inequalities and Applications, 2011
In this paper, the Hyers-Ulam stability of the Pexider functional equation in a non-Archimedean space is investigated, where σ is an involution in the domain of the given mapping f.
Vaezpour Seiyed, Saadati Reza, Sadeghi Zahra   +2 more
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