Professor Emeritus Elijah Lucien Polak, a distinguished researcher, dedicated educator, and cherished member of the campus community, passed away on June 12 at age 94.
Polak joined the Berkeley faculty in 1961, embarking on a remarkable career that spanned more than six decades. Over his long and illustrious tenure, he made foundational and enduring contributions to the fields of control systems, optimization theory and numerical algorithms. He is perhaps more globally recognized as the co-creator of the Polak-Ribière method, a seminal conjugate gradient algorithm that remains a fundamental tool in mathematical optimization and modern machine learning applications.
Throughout his time at Berkeley, Polak was highly regarded not only for his rigorous mathematical scholarship but also for his deep commitment to mentoring generations of students and supporting his colleagues. His work helped cement UC Berkeley’s reputation as a world leader in control systems and optimization.
