Abstract This special issue is dedicated to the memory of Raytcho Lazarov, who passed away on November 30, 2024. The articles collected here reflect some of his principal research interests, particularly in numerical methods for partial differential equations and the development of algorithms for their efficient and reliable application. We briefly highlight his major scientific contributions and provide an overview of the results presented in this volume. The contributions are authored by his former students, colleagues, coauthors, and long-term collaborators – researchers whose work has been deeply influenced by Lazarov’s ideas and achievements. Over more than half a century of remarkably productive scholarship, he made fundamental contributions across a broad range of important areas in computational and applied mathematics.
Langer et al. (Thu,) studied this question.