The aim of this volume, Functional Equations and Ulam’s Problem, is to publish a well-balanced collection of works devoted to the domain of functional equations with emphasis on stability results associated with Ulam’s problem for approximate homomorphisms. This area has been a source of active and vibrant research for more than five decades. Efforts have been made for the book to constitute a valuable reference for graduate students and advanced research scientists who wish to be introduced to the state-of-the art knowledge on the problems treated, as well as to obtain an overview of important results on stability theory, from classical to the most recent.

The contributions in this collection investigate the following topics: functional equations on a semigroup, generalized Euler-Lagrange cubic functional equations, Ulam stability results for the Davison functional equation, Hyers-Ulam stability of a pexiderized functional equation, Ulam-Hyers stability in normed spaces, Hyers-Ulam stabilities for weighted operators, stability conditions for linear functional-differential equations, semilinear functional differential equations, general bi-Jensen functional equation, norm inequalities for the Chebyshev functional in Hilbert spaces, orthogonality and generalized additive mappings in Banach modules, permuting triderivations and permuting trihomomorphisms in complex Banach algebras, bi-quadratic derivations and bi-quadratic homomorphisms in Banach algebras, novel representations of mappings, linear and affine sets and relations, and solvability relations in groupoids.