This is a special issue of the journal devoted to the 60th birthday of an outstanding Ukrainian mathematician, one of the founders of our journal Professor Vitaliy Sushchansky.

Vitaliy Sushchansky was born on November 14, 1946 in Khodorkiv, Zhytomyr oblast, Ukraine. He graduated Kyiv State Taras Shevchenko University in 1969 and defended there his Candidate of Sciences thesis“Wreath products of elementary abelian groups and their applications” in 1971. His teacher and scientific advisor was a famous algebraist Leo Kaloujnine.Vitaliy Sushchansky defended his Doctor of Sciences thesis“Wreath products, isometries of semifinite Baire metrics and residually finite groups” in 1991 in Saint Petersburg.

From 1971 till 2004 Vitaliy Sushchansky worked on Algebra and Mathematical Logics department at Kyiv Taras Shevchenko University: as Assistant Professor at the beginning, Docent (Associate Professor) since 1980 and Professor since 1991. Currently he is Professor of Mathematics at Silesian Institute of Technology in Gliwice, Poland. From 1998 till 2004 he served as the head of the department of Algebra and Mathematical Logics in Kyiv Taras Shevchenko University.

Vitaliy Sushchansky works in various areas of algebra. A substantial part of his research is devoted to automorphism groups of trees and related constructions (wreath products, Sylow subgroups of symmetric groups, ultrametric spaces, automata, etc). He is one of the founders of this modern and rapidly developing branch of group theory. His example of an infinite two-generated p-group published in 1979 is one of the first examples from an important class of groups of branch type. A modern account on this example can be read in this issue in the paper “On Sushchansky p- groups” by young mathematicians I. Bondarenko and D. Savchuk. Professor Sushchansky has constructed subsequently other interesting examples of groups and has initiated a systematic study of automorphism groups of rooted trees and ultrametric spaces. The school of geometric group theory established in Kyiv by Vitaliy Ivanovych is a reconized center of research in this field.

Other areas of interest of Vitaliy Sushchansky include relation algebras, Galois correspondences, locally finite groups, combinatorics of finite metric spaces, etc. He has published over 90 research papers and books.

Vitaliy Ivanovych Sushchansky is known not only for his research but also for his devoted service to the Ukrainian mathematical community. He is a constant member of the program committee and organizer of the biannual International Algebraic Conference in Ukraine. Several years ago he had a great idea of organizing a seminar “At the end of the year” to use the opportunity of seeing Kyiv mathematicians coming from abroad during the Christmas break. This seminar became now a traditional yearly event. He is also an organizer of the regular Group Theory seminar in Kyiv University, which is one of the most important focal points of group theory in Ukraine.

Professor Vitaliy Sushchansky is a very devoted teacher and scientific advisor. Under his supervision 31 Ph.D. and three Doctor of Sciences thesis were defended. He is investing a great amount of his energy in the education of the new generation of Ukrainian mathematicians. An important example of his involvement is his service as the editor in chief of the mathematical journal for Ukrainian pupils “In the World of Mathematics”, where he is also a frequent author of articles popularizing Mathematics and its history in Ukraine.

We warmly congratulate Vitaliy Ivanovich on the occasion of his 60th birthday and wish him strong health and many successful years of research and teaching.

V. A. Artamonov, O. E. Bezushchak,
Yu. A. Drozd, V. M. Futorny,
R. I. Grigorchuk, A. I. Kashu,
V. V. Kirichenko, M. Ya. Komarnytskyj,
L. A. Kurdachenko, Ya. V. Lavrenyuk,
V. V. Nekrashevych, B. V. Novikov,
A. S. Oliynyk, A. Yu. Olshanskii,
M. O. Perestyuk, A. P. Petravchuk,
M. Sapir, L. A. Shemetkov,
I. P. Shestakov, E. I. Zelmanov.