@article{Park2022, 
author = {Choonkil Park and Abbas Najati and Batool Noori and Mohammad B. Moghimi},
title = {Additive and Fréchet functional equations on restricted domains with some characterizations of inner product spaces},
year = {2022},
journal = {AIMS Mathematics},
volume = {7},
number = {3},
pages = {3379-3394},
keywords = {Hyers-Ulam stability, quadratic functional equation, Fréchet functional equation, asymptotic behavior},
url = {https://www.sciopen.com/article/10.3934/math.2022188},
doi = {10.3934/math.2022188},
abstract = {In this paper, we investigate the Hyers-Ulam stability of additive and Fréchet functional equations on restricted domains. We improve the bounds and thus the results obtained by S. M. Jung and J. M. Rassias. As a consequence, we obtain asymptotic behaviors of functional equations of different types. One of the objectives of this paper is to bring out the involvement of functional equations in various characterizations of inner product spaces.}
}