With sadness, we regret to inform you about the passing of Prof. Dr. Viorel-Puiu Paun (1954–2024), Associate Editor of Fractal and Fractional (ISSN: 2504-3110). We are grateful for his many contributions to the journal and the legacy his research has left in the academic world.

Prof. Dr. Viorel-Puiu Paun was a full university professor of physics at the “Politehnica” University of Bucharest, Romania, Faculty of Applied Sciences, Physics Department and a corresponding member of the Academy of Romanian Scientists. Prof. Dr. Viorel-Puiu Paun completed his studies at the Faculty of Physics, University of Bucharest (1979), and Faculty of Mathematics, University of Bucharest (1990), with a Ph.D. in physics from the Institute of Atomic Physics in Bucharest and a postgraduate diploma in biomedical engineering from EPF Lausanne, Switzerland.

Prof. Dr. Viorel-Puiu Paun has published more than 150 papers in national and international journals, 117 ISI journal papers, 50 communications in national and international meetings (more than 30 on invitation), 594 citations without self-citations, and 22 books, chapters in books, and monographs. Without a doubt, he was a great inspiration to his colleagues and a great mentor to all of his students.

His passing creates a huge void not only in his department but also in our journal. His death is a significant loss to the academic community as well as to anyone close to him, on both a professional and a personal level. We offer our deepest condolences to his family, friends, and colleagues.