Orthogonality and Generalized Additive Mappings in Banach Modules
摘要
Using the fixed point method, we prove the Hyers-Ulam stability of the following generalized Jensen functional equation \(\displaystyle f\left (\frac {\sum _{i=1}^n x_i}{n}\right )+\sum _{i=1}^n f\left (\frac {\sum _{i=1,i\neq j}^n x_i -(n-1)x_j}{n}\right )=f(x_1)\quad (n\geq 2) \) in Banach modules over a unital \(C^*\) -algebra and in non-Archimedean Banach modules over a unital \(C^*\) -algebra associated with the orthogonally Jensen functional equation.