CONTENTS Introduction ??1. Preliminary information ??2. Construction of particular solutions for a difference equation of hypergeometric type on non-uniform lattices ??3. Some properties of difference functions of hypergeometric type ??4. Classical orthogonal polynomials of a discrete variable on non-uniform lattices ??5. Functions of a discrete variable of the second kind ??6. Some solutions of a difference equation of hypergeometric type on non-uniform lattices Conclusion Appendix. A transformation of the original equation References

The theory of difference analogues of special functions of hypergeometric type

A list of Ya. Smorodinsky’s articles published in science journals is presented.

List of Ya.A. Smorodinsky’s publications

The present paper is a review of research on double expansions of relativistic amplitudes. In the beginning of the review the general theory of the expansion of functions stipulated in both the time-like and space-like domains is presented; then the general theory of the expansion of a scalar function and a function with spin is presented. After that various coordinate systems and matrices for the transition from certain basis functions to other ones are indicated. The review likewise considers certain corollaries deriving from the existence of relativistic expansions.

M. A. Liberman

Papers

Two-Dimensional Expansions of Relativistic Amplitudes