ISOMORPHISMS IN QUASI-BANACH ALGEBRAS

Using the Hyers-Ulam-Rassias stability method, we inves-tigate isomorphisms in quasi-Banach algebras and derivations on quasi-Banach algebras associated with the CauchyJensen functional equation 2f(x + y/2+ z) = f(x) + f(y) + 2 f(z), which was introduced and investigated in [2, 17]. The concept of HyersUlamRassias stability originated from the Th. M. Rassias’ stability the-orem that appeared in the paper: On the stability of the linear mappingin Banach spaces, Proc. Amer. Math. Soc.72 (1978), 297-300. Further-more, isometries and isometric isomorphisms in quasi-Banach algebrasare studied. Using the Hyers-Ulam-Rassias stability method, we inves-tigate isomorphisms in quasi-Banach algebras and derivations on quasi-Banach algebras associated with the CauchyJensen functional equation 2f(x + y/2+ z) = f(x) + f(y) + 2 f(z), which was introduced and investigated in [2, 17]. The concept of HyersUlamRassias stability originated from the Th. M. Rassias’ stability the-orem that appeared in the paper: On the stability of the linear mappingin Banach spaces, Proc. Amer. Math. Soc.72 (1978), 297-300. Further-more, isometries and isometric isomorphisms in quasi-Banach algebrasare studied. KCI Citation Count: 4