In Loving Memory

Today, early morning, I learned that Ravi passed away. It's hard to express my feelings right now. Ravi wasn't just a very valuable and hardworking mathematician; he was also a great person, a very kind friend, and a wise guide.

I attended the "The International Conference on the Theory, Methods and Applications of Nonlinear Equations, Texas A&M University-Kingsville, Kingsville, Texas 78363 USA, December 17 – December 21, 2012," organized by Ravi, as an invited speaker. I will never forget his hospitality there, especially how he welcomed the speakers from Türkiye. This was the beginning of our friendship and co-authorship. We later published numerous articles and two scientific books together. He constantly encouraged me by saying and writing in the emails "the best metrics fixed-point researcher." He continuously supported me in expanding my research with suggestions and interesting questions. He sent me thousands of articles to review because he truly trusted me. And I always acted on his advice and never let him down. He loved Türkiye very much. I know he helped and supported many Turkish researchers. In fact, he was a person who tried to help everyone; because he was a good person.

He has gladly participated in and made significant contributions to many scientific meetings held in Türkiye. While I can't list them all individually, I particularly remember these meetings: He was the keynote speaker at the "International Conference Anatolian Communications in Nonlinear Analysis, Abant Izzet Baysal University, Bolu, Turkey, July 03-06, 2013," which I co-organized. Again, together, we participated as keynote speakers at the "International Congress in Honour of Professor Ravi P. Agarwal, Uludag University, Bursa, Turkey, June 23-26, 2014." In 2015, he was the keynote speaker at the 11th "International Conference on Fixed Point Theory and its Application," which I organized. Most recently, he was the keynote speaker at the "International Conference on Applied Mathematics and Analysis (ICAMA2016)," which I also co-organized, to be held on July 11-13, 2016, at Atilim University, Ankara, Turkey. He was in Turkey during the attempted coup on July 15, 2016. As far as I remember, 2016 was the last year we spent together in Türkiye. After that, we were able to meet at a few conferences in Romania.

The best place to spend time with a highly productive and hardworking mathematician like Ravi was, naturally, academic meetings. But our communication wasn't limited to these meetings. We were constantly in touch via email. We didn't just correspond for work; we communicated in a spirit of friendship and solidarity.

He had expressed his desire to visit Türkiye again. Unfortunately, we weren't able to hold a scientific meeting where we could invite him: I'm sorry about that. I offer my condolences to Sadhna on this great loss. I pray for her patience.

Erdal Karapinar

Professor Ravi Agarwal was far more than my PhD supervisor at the National University of Singapore. He was my teacher, my mentor, my collaborator, and a guiding presence throughout my academic life. I first learned from him as a third-year undergraduate student in his Numerical Analysis course. He later supervised my MSc research and then my PhD, shaping my development at every critical stage of my education. Even after I completed my doctoral studies, our connection did not end. We continued to work closely together for many years, producing 121 joint research papers and four monographs. Looking back, I realize how rare and precious such a lifelong scholarly partnership is.

What I admired most about Professor Agarwal was his extraordinary enthusiasm for mathematics. His passion was constant and sincere, and it never faded with time or circumstance. No matter how difficult a problem seemed, how slow progress felt, or how challenging life became, his advice to me was always the same: “Just keep working.” These words became deeply engraved in my mind. They reflected his belief that perseverance, patience, and honest effort matter more than brilliance or speed. When I felt discouraged, his calm confidence reminded me that steady work itself has value, and that persistence would eventually lead to understanding. Over the years, this philosophy influenced not only my approach to research, but also how I face challenges in life.

Professor Agarwal lived exactly as he advised. After retiring from Texas A&M University–Kingsville in June 2024, he was appointed Emeritus Research Professor at the Florida Institute of Technology. Retirement did not slow him down. True to his own words, he continued to “just keep working,” and in 2025 he published his 54th book, IMU, ICM, Medals, Prizes, and Laureates (MDPI, 234 pages). Even in the later stages of his life, his curiosity, discipline, and love for mathematics remained as strong as ever.

Beyond his remarkable academic achievements, Professor Agarwal was a kind, thoughtful, and generous human being. I experienced this kindness personally during my one-month visit to the Florida Institute of Technology in 2005. He knew that I was a picky eater and unlikely to cook for myself. Without making a fuss, he ensured that I was well taken care of by bringing me to his home for dinner every evening, where I could enjoy the delicious meals prepared by Mrs. Agarwal. This simple but deeply caring gesture touched me greatly. My mother, to this day, remains profoundly grateful for his thoughtfulness and warmth.

I will always remember Professor Agarwal with deep respect and affection. The lessons he taught me—through his words, his actions, and his unwavering dedication—will stay with me for the rest of my life. I am forever thankful for his guidance, his generosity, and his belief in me. His influence continues to shape who I am, and his legacy will live on in the many students he inspired and in the mathematics he loved so deeply.

Patricia J. Y. Wong