Renowned CU Boulder Mathematician Found Dead Unexpectedly at 58
The University of Colorado Boulder community is mourning the sudden loss of Dr. Keith Julien, an internationally respected scholar and the Chair of the Department of Applied Mathematics, who passed away unexpectedly on April 14, 2024, at the age of 58.
Dr. Julien’s death sent waves of shock and sadness throughout the campus and the global academic community, where he 
A Legacy of Intellectual Excellence
Born in 1965, Keith Julien earned his Ph.D. from Imperial College London and quickly established himself as a leader in the field of applied mathematics. He joined CU Boulder in the mid-1990s, and over the course of nearly three decades, he not only contributed to some of the most challenging problems in fluid dynamics but also transformed the department through visionary leadership and collaborative spirit.
His research focused on the fundamental mathematical modeling of convection and turbulence in planetary and stellar environments—a cornerstone for understanding climate systems, ocean currents, and solar physics. His work was funded by prestigious grants from NASA, the National Science Foundation, and other leading agencies.
“Keith was a brilliant mind, but what made him truly unique was his ability to bridge complex mathematical theory with physical phenomena,” said Dr. Anne Schmidt, a longtime colleague in the Department of Physics. “He brought a profound curiosity to every project and inspired everyone around him.”
A Beloved Mentor and Leader
Beyond his research, Dr. Julien was deeply committed to mentoring the next generation of scientists and mathematicians. Over his career, he supervised more than 20 Ph.D. students and numerous postdoctoral researchers, many of whom have gone on to prestigious careers in academia, government, and industry.
Former student Dr. Ravi Narayan, now a professor at Stanford University, remembers Julien as “a rare mentor who truly listened. He didn’t just guide us through equations; he helped shape our way of thinking about science and the world.”
As Chair of the Department of Applied Mathematics, Julien led several transformative initiatives, including the launch of interdisciplinary degree programs and the expansion of computational research capabilities. One of his proudest achievements was securing funding and overseeing plans for a new shared research facility between the Applied Mathematics and Chemistry departments—an effort aimed at fostering cross-disciplinary innovation.
“He believed in collaboration over competition,” said Dr. Linda Carver, Assistant Dean of the College of Arts and Sciences. “Keith built bridges—not only between disciplines but also between people.”
A Personal Side to a Public Figure
While his academic accomplishments were widely known, colleagues and students also remember Julien for his warmth, humility, and humor. He was an avid hiker, a lover of classical music, and an active participant in campus life. He regularly attended student presentations, departmental picnics, and faculty coffee hours.
“He always remembered your name and asked how you were doing, even if you had only met him once,” said graduate student Priya Desai. “He had a way of making everyone feel seen.”
Friends close to Julien described him as someone who balanced the rigors of academia with a deep appreciation for the natural world. He was particularly drawn to the Colorado wilderness and often said that hiking the Flatirons helped him clear his mind and think through difficult problems.
Julien is survived by his wife, Elena, a fellow mathematician, and their two children, David and Clara, both college students. In a statement, his family expressed gratitude for the outpouring of support: “Keith was a dedicated father, husband, and teacher. We are touched by the countless stories being shared and thankful for the community he loved so dearly.”
A Community in Mourning
In the days following his passing, tributes poured in from universities and research institutions around the world. The American Mathematical Society, of which Julien was a long-standing member, released a statement calling him “a titan in the field whose contributions will resonate for generations.”
CU Boulder has established a memorial scholarship in his name to support graduate students in applied mathematics who exhibit excellence in research and community engagement—two hallmarks of Julien’s career. Plans are also underway for a memorial lecture series, with the inaugural keynote to be delivered next spring by one of Julien’s former collaborators at Princeton.
On April 20, hundreds gathered at Macky Auditorium to celebrate Julien’s life. The event featured remarks from university officials, former students, and international colleagues, as well as a chamber music performance of his favorite Bach concerto. In a particularly moving tribute, a group of graduate students presented a collaborative research paper they had been developing under Julien’s guidance—now completed and submitted for publication in his honor.
“We lost not just a brilliant academic, but a true pillar of our community,” said CU Chancellor Philip DiStefano during the service. “Keith Julien exemplified the ideals of scholarship, mentorship, and humanity. His legacy will continue to inspire and uplift all of us.”
Looking Ahead
Though the loss of Dr. Keith Julien leaves a deep void, the work he began will continue through the people he mentored, the programs he built, and the ideas he championed.
The Department of Applied Mathematics is currently organizing a symposium to celebrate his scientific legacy, bringing together collaborators from around the world. Meanwhile, faculty and students are carrying forward the research projects he was most passionate about, honoring his memory through their continued pursuit of knowledge.
“Keith believed that science could help us understand not just the world, but our place in it,” said Dr. Sandra Velasquez, a colleague in atmospheric science. “We will miss him dearly—but we will carry forward the light he brought into our lives.”
