Functional equations of trigonometric functions

Stability of Trigonometric Functional Equations in Generalized Functions

On the Stability of Trigonometric Functional Equations

On a Generalized Hyers-Ulam Stability of Trigonometric Functional Equations

The Hyers-Ulam stability problems of functional equations go back to 1940 when S. M. Ulam proposed a question concerning the approximate homomorphisms from a group to a metric group see 1 . A partial answer was given by Hyers et al. 2, 3 under the assumption that the target space of the involved mappings is a Banach space. After the result of Hyers, Aoki 4 , and Bourgin 5, 6 dealt with this pro...

Monodromy of Trigonometric Kz Equations

The famous Drinfeld-Kohno theorem for simple Lie algebras states that the monodromy representation of the Knizhnik-Zamolodchikov equations for these Lie algebras expresses explicitly via R-matrices of the corresponding Drinfeld-Jimbo quantum groups. This result was generalized by the second author to simple Lie superalgebras of type A-G. In this paper, we generalize the Drinfeld-Kohno theorem t...

Functional Equations and Distribution Functions

We consider the functional equation f(t) = 1 b b?1 X =0 f t ? a for all t 2 IR; (F) where 0 < a < 1, b 2 IN n f1g and ?1 = 0 1 : : : b?1 = 1 are given parameters, f : IR ! IR is the unknown. We show that there is a unique bounded function f which solves (F) and satisses f(t) = 0 for t < ?1=(1 ? a), f(t) = 1 for t > 1=(1 ? a). This solution can be interpreted as the distribution function of a ce...