Search results for "Ulam stability"
showing 3 items of 3 documents
Ulam Stability for the Composition of Operators
2020
Working in the setting of Banach spaces, we give a simpler proof of a result concerning the Ulam stability of the composition of operators. Several applications are provided. Then, we give an example of a discrete semigroup with Ulam unstable members and an example of Ulam stable operators on a Banach space, such that their sum is not Ulam stable. Another example is concerned with a C 0 -semigroup ( T t ) t &ge
Random Stability of an Additive-Quadratic-Quartic Functional Equation
2010
Using the fixed point method, we prove the generalized Hyers-Ulam stability of the following additive-quadratic-quartic functional equation f(x+2y)+f(x−2y)=2f(x+y)+2f(−x−y)+2f(x−y)+2f(y−x)−4f(−x)−2f(x)+f(2y)+f(−2y)−4f(y)−4f(−y) in complete random normed spaces.
A C0-Semigroup of Ulam Unstable Operators
2020
The Ulam stability of the composition of two Ulam stable operators has been investigated by several authors. Composition of operators is a key concept when speaking about C0-semigroups. Examples of C0-semigroups formed with Ulam stable operators are known. In this paper, we construct a C0-semigroup (Rt)t&ge