


Paper Title:
Solution of the HyersUlam Stability Problem for Quadratic Type Functional Equations in Several Variables
Author(s):
John Michael Rassias
Pedagogical Department, E.E., National and Capodistrian University of Athens,
Section of Mathematics and Informatics,
4, Agamemnonos Str., Aghia Paraskevi,
Athens 15342,
Greece
jrassias@primedu.uoa.gr
URL: http://www.primedu.uoa.gr/~jrassias/
Abstract:
In 1940 (and 1968) S. M. Ulam proposed the wellknown Ulam stability problem. In 1941 D. H. Hyers solved the HyersUlam problem for linear mappings. In 1951 D. G. Bourgin has been the second author treating the Ulam problem for additive mappings. In 1978 according to P. M. Gruber this kind of stability problems is of particular interest in probability theory and in the case of functional equations of different types. In 19822004 we established the HyersUlam stability for the Ulam problem for different mappings. In this article we solve the HyersUlam problem for quadratic type functional equations in several variables. These stability results can be applied in stochastic analysis, financial and actuarial mathematics, as well as in psychology and sociology.
Full Text PDF: