We congratulate Dr. Mariusz Urbański for being the recipient of the prestigious 2023 Sierpiński Medal. This international award is given to outstanding mathematicians with Polish associations (the first awardee was Kazimierz Kuratowski). It is the highest honor presented by the University of Warsaw (Faculty of Mathematics, Informatics, and Mechanics) together with the Polish Mathematical Society since the medal's inception in 1974. In celebration of the award, Dr. Urbanski delivered the 2023 Sierpiński Lecture on May 11, 2023.

Before joining UNT, Dr. Urbański has received his Ph.D. with degree specialization in dynamical systems from Nicolaus Copernicus University in Poland 1985, and his habilitation from Mathematical Institute of the Polish Academy of Sciences in 1991. His research interests include various areas in mathematics, such as dynamical systems, ergodic theory, iterated function system, number theory, topology, etc. His work has been continuously supported by federal grants and private foundations. As the author of 5 multivolume books (and 1 more two-volume-book accepted) and more than 200 publications, Dr. Urbanski has been invited to give scientific talks all over the world. He has also been recognized among the top 2% of the most cited mathematics according to a study led by a statistician at Stanford University.

Dr. Urbański says it is amazing to be among recipients that include great mathematicians, and he is full of joy and gratitude for Polish mathematical community. He would also like to express his gratitude to the University of North Texas, its Department of Mathematics, and the chair Dr. Ralf Schmidt for the friendly working environment and support in all aspects of his professional activity.

Congratulations, Mariusz!