Professor Oldřich Kowalski passed away

This paper is dedicated to the me­mo­ry of Professor Kowalski who was one of the leading re­sear­chers in the field of dif­fe­ren­tial geometry and especially Rie­mannian and affine geometry. He signif­icantly contributed to rai­sing the level of teaching dif­fe­ren­tial geometry by careful and sys­tematic preparation of lectures for students. Prof. Kowalski is the author or co-author of more than 170 professional articles in internation­ally recognized jour­nals, two monographs, text books for students. Prof. Kowalski collaborated with many mathematicians from other countries, particularly from Belgium, Italy, Ja­pan, Romania, Russia, Morocco, Spain and others. With the death of Professor Oldřich Kowalský mathe­matical community are losing a significant personality and an exceptional colleague, a kind and dedicated teacher, a man of high moral qualities.