Professor Emeritus Dimitri Bertsekas, influential computer scientist and prolific author, dies at 83

Dimitri Bertsekas PhD ’71, the Jerry McAfee (1940) Emeritus Professor in Engineering in the Department of Electrical Engineering and Computer Science (EECS), a principal investigator in the Laboratory for Information and Decision Systems (LIDS), and the Fulton Professor of Computational Decision Making at Arizona State University, died on June 3 at his home in Belmont, Massachusetts. He was 83 years old. Over the course of his career, Bertsekas’ research spanned, and had a definitive influence upon, several fields, including optimization, control, large-scale computation, reinforcement learning, and artificial intelligence. He served as a consultant to various private companies; an editor for several scientific journals; the founder of a publishing company, Athena Scientific; and chief scientific advisor of Bayforest Technologies, a London-based quantitative investment company. However, his most lasting impact may have come through his prolific authorship and co-authorship of over 20 highly influential books, monographs, and textbooks, and through his vast network of students, mentees, friends, and collaborators.Bertsekas earned his undergraduate degree at the National Technical University of Athens, Greece, before obtaining his MS in electrical engineering at George Washington University in 1969, and his PhD in system science at MIT in 1971. He began his faculty career at Stanford University, where he spent three years, and the University of Illinois at Urbana-Champaign, where he spent five more before returning to MIT in 1979. He would stay with MIT’s Department of EECS until 2019, at which point he became a full-time faculty member at Arizona State University at Tempe. Along the way, Bertsekas taught, advised, and mentored students who would eventually become his colleagues at all four institutions. “Dimitri played a defining role in my career,” says Asu Ozdaglar, department head of EECS at MIT. “I decided to change my research focus after taking his nonlinear optimization class. The conceptual clarity and the mathematical rigor he has brought to every topic, combined with his ability to connect theory to important problems established a foundation that has continued to inform my scholarly work in the years to follow.” Another former MIT student, Jinane Abounadi, now executive director of the MIT Sandbox Innovation Fund Program, still remembers Bertsekas’ tutelage as a highlight of her time as a student at MIT: “I feel so fortunate to have had Dimitri as my professor and advisor. I had the opportunity to learn about optimization, dynamic programming, and neuro-dynamic programming from a true master.” A former student at the University of Illinois, Steven E. Shreve remembers being impressed by Bertsekas’ course on nonlinear optimization and asking if Bertsekas would consider becoming his PhD advisor. “Rather than answering my question directly, Dimitri gave me a preliminary draft of his manuscript, which eventually became his book ‘Dynamic Programming and Stochastic Control,’ and asked me to proofread it,” remembers Shreve, now Orion Hoch University Professor Emeritus in the Department of Mathematical Sciences at Carnegie Mellon University. “From this manuscript, I learned the theory of dynamic programming and mastered many important special cases. Talking with Dimitri as I read, I received one-on-one instruction. When the book finally appeared, Dimitri generously acknowledged my participation, as if I had done him a favor, rather than the other way around.” The gambit was typical of Bertsekas’ understated approach to mentorship; after the first successful collaboration, Bertsekas arranged a research fellowship for Shreve and challenged him to solve a fundamental question in dynamic programming. “I needed to learn a good deal of set theory to even think about the question he asked,” remembers Shreve, whose work on the problem was combined with Bertsekas’ notes to create their co-authored book “Stochastic Optimal Control: The Discrete Time Case.” “Working with Dimitri on [that book] is how I learned to write,” says Shreve. “I learned from Dimitri that if you want to be recognized for your research, you must present it so others want to read it, and I learned how to do that.” The clarity and elegance of Bertsekas’ explanatory style would become his educational hallmark. “Everyone recognized Dimitri’s great talents as a writer, but he went far beyond that, organizing entire subjects into something that was understandable and a well-organized totality,” says Robert Gallager, professor emeritus of electrical engineering at MIT, who co-authored a 1987 book with Bertsekas entitled “Data Networks.” “The field was changing rapidly then, with a factor-of-two decrease every two years in computation costs, and with optical fiber on the horizon for transmission. Dimitri and I each understood only parts of this field, with the rest a fast-moving learning experience. Dimitri was the ideal partner in this, able to quickly translate hard concepts into simple but accurate explanations and able to combine my knowledge with his into an understandable whole.” Bertsekas’ close colleague in LIDS, Munther Dahleh, remembers, “what always struck me was that, through his writing, one could almost hear Dimitri speaking directly to the reader. His intuition, clarity of thought, and distinctive perspective come through beautifully in his books. They reflect not only his profound technical contributions, but also his passion for teaching and his desire to help others understand the subject at a deep level. … In particular, his joint book with John Tsitsiklis on neuro-dynamic programming is a tour de force. It anticipated and helped define many of the ideas that later became central to reinforcement learning and approximate dynamic programming.” Tsitsiklis himself remembers the co-writing process with Bertsekas fondly: “For Dimitri, research was a creative form, combining craftsmanship and the creativity that we usually call art.” The definition of art and its practice was a subject of great fascination for Bertsekas, and one that he explored at length in his 2025 essay, “Academia, Art, and Life,” an attempt to meaningfully categorize creative work into three broadly descriptive roles — technician, craftsman, and artist — and to explore the overlaps between the three types of practice. Beyond his clear and lucid writing, Bertsekas was known for his strong graphic eye, a talent which he put to good use not only developing illustrations for all his textbooks, but in taking memorable and artistically inspired photographs of his worldwide travels. Longtime collaborator and friend David Castañón, now a professor of electrical and computer engineering at Boston University, remembers Bertsekas as a true Renaissance man who drew inspiration from countless sources: “Dimitri had an insatiable curiosity for algorithmic ideas, both theory and practice. Many of these ideas were inspired by new technologies (parallel computers, reinforcement learning, chess-playing algorithms) … Whenever we met, Dimitri would introduce new concepts of interest; we would work out theoretical details, design and conduct numerical experiments, and generate results. Then, Dimitri’s artistic talents would take over: designing graphics to illustrate concepts, typesetting text and figures for the papers to be completed. He had a rare gift for generating concise explanations of complex concepts. These talents led to his publishing company Athena Scientific, where Dimitri and his coauthors generated elegant pedagogical volumes with broad appeal.” Tsitsiklis agrees, noting, “for Dimitri, [research] was about discovering meaning, to uncover the ‘right’ way to view a subject, enrich it, and convey it in a crystal-clear manner through his prolific writings.” Many of the 20-plus books either authored or co-authored by Bertsekas were adopted for use as textbooks at MIT in subjects including data networks, nonlinear programming, dynamic programming, network optimization, parallel and distributed computation, neuro-dynamic programming, convex analysis and optimization, probability, and reinforcement learning. Stephen Boyd, Samsung Professor in the School of Engineering at Stanford, testifies to the great impact of Bertsekas’ collected works: “generations of researchers in optimization, control, and many related areas learned these topics from Dimitri’s exquisitely clear and beautifully written text books. I was one of them; indeed, I went into these fields in no small part because of Dimitri’s books, and his influence has been with me the whole time.”That influence can be measured by the sheer number of awards and honors Bertsekas accumulated over the course of his career, including the INFORMS 1997 Prize for Research Excellence in the Interface Between Operations Research and Computer Science for Neuro-Dynamic Programming, the 2001 ACC John R. Ragazzini Education Award, the 2009 INFORMS Expository Writing Award, the 2014 ACC Richard E. Bellman Control Heritage Award for “contributions to the foundations of deterministic and stochastic optimization-based methods in systems and control,” the 2014 Khachiyan Prize for Life-Time Accomplishments in Optimization, the SIAM/MOS 2015 George B. Dantzig Prize, and the 2022 IEEE Control Systems Award. Together with his coauthor John Tsitsiklis, he was awarded the 2018 INFORMS John von Neumann Theory Prize for the contributions of the research monographs “Parallel and Distributed Computation” and “Neuro-Dynamic Programming.” In 2001, Bertsekas was elected to the U.S. National Academy of Engineering for “pioneering contributions to fundamental research, practice and education of optimization/control theory.”However, a more personal measure of Bertsekas’ impact can be taken by the warmth and affection with which his friends, co-workers, and former students uniformly remember him. Co-author John Tsitsiklis wrote, “I was most fortunate to be one of his apprentices, and to have lived his warmth and friendship.” His former student at MIT, Angelia Nedich, later became Bertsekas’ colleague at Arizona State University. She remembers: “Dimitri was an exceptional mind, a gifted soul that shed light for us seekers, but at the same time he was very humble as he enjoyed simple moments of life, a sip of good coffee, a bite of flavorful food, or a glass of spicy margarita on our road trips in Southwest. That is how I love to remember him.”Former student Benjamin Van Roy, now a professor at Stanford, wrote about the transformation of Bertsekas from authority figure to friend (and the subject of friendly teasing). “I recall the intimidating comments of more senior PhD students as I began my own PhD journey in LIDS. Some referred to Dimitri as an “immortal.” Another comment I recall fondly — and often reminded Dimitri about — was: “Professor Bertsekas is a very handsome man!” Their bond continued long after Van Roy’s graduation. “Dimitri was a treasure to humanity: one of the great scholars of our time, a Renaissance man, and a phenomenal role model. I was privileged to be among the many he mentored, and even more privileged to count him as a longtime friend.” Yuchao Li, a postdoc mentored by Bertsekas at Arizona State University, remembers his mentor as an almost inexhaustible source of both inspiration and support: “For me, Professor Bertsekas was like a loving father, full of infinite wisdom. … He seemed to know everything, yet he remained deeply humble and open-minded. He was always eager to help, even at the slightest sign of difficulty in my life. He instilled in me a lasting faith in the very best qualities of human beings, and I will strive to carry that faith forward.”Bertsekas was preceded in death by his son Costas. He is survived by his wife Joanna Bertsekas (née Palashas); his son Telis Bertsekas and his wife Wendy Bertsekas; and three grandchildren, Melina, Alexandros, and Leonidas.