Alexander “Sasha” Davydov, who completed his PhD in mechanical engineering at UC Santa Barbara in 2025, has received the prestigious Winifred and Louis Lancaster Dissertation Award from the UCSB Graduate Division.
Presented annually, the Lancaster Award recognizes dissertations that make significant methodological contributions to their fields. Davydov received the award in mathematics, physical sciences and engineering for his dissertation, “Contraction Theory in Control, Learning, and Optimization.” Sienna Helena Parker, a PhD candidate in the Technology Management Department, also received a Lancaster Award this year, marking the first time that two scholars from UCSB’s Robert Mehrabian College of Engineering have received the honor in the same year.
“I am delighted to congratulate Sasha Davydov and Sienna Helena Parker on receiving this prestigious recognition,” said Umesh Mishra, dean of The Robert Mehrabian College of Engineering. “Their achievements reflect not only the extraordinary quality of their individual scholarship, but also the breadth and depth of research taking place across our college. From advancing the mathematical foundations of safe and reliable engineering systems to examining how technology is reshaping work and society, their dissertations demonstrate the kind of rigorous, impactful research that defines engineering at UCSB.”
Advised by mechanical engineering professor Francesco Bullo, Davydov received the award in mathematics, physical sciences and engineering for his dissertation, “Contraction Theory in Control, Learning, and Optimization.” Davydov said that the honor was extremely meaningful.
“It felt great to get the news that I was awarded the Lancaster for my dissertation,” he said. “The dissertation is the culmination of my years at UCSB and my research over that time.”
His work is rooted in control theory, an interdisciplinary field of engineering concerned with shaping the behavior of dynamic systems through feedback. As Davydov explains, control theory is “the underlying technology enabling automatic cruise control, temperature control in buildings, autopilot in airplanes, and other technologies we take for granted.”
Central to his dissertation is contraction theory, which Davydov described as “essentially a robust notion of stability” that offers “many useful corollaries for physical engineering systems.” He first encountered the topic during a special-topics course taught by Bullo. A final project for that course led him to a missing mathematical connection in the theory, one he found in a 1961 mathematics paper, and that became the foundation for his first journal paper at UCSB.
“After that, I was hooked, and I spent the rest of my time at UCSB working on this topic,” Davydov said.
In practical terms, contraction theory helps researchers understand whether complex systems will converge toward reliable behavior, even when they face uncertainty, disturbances, or changing conditions. Davydov’s dissertation extends those ideas across control, learning, and optimization, with potential applications in autonomous systems, robotics, machine learning, and other technologies that must operate safely, and predictably in the real world.
“In terms of my research goals, I am interested in developing theory that enables the reliable control of physical engineering systems,” Davydov said. “Many physical systems extend beyond our current capabilities to analyze mathematically. I hope to bring new tools from control theory, optimization theory, and machine learning to better understand them and design strategies for them to operate safely and reliably.”
Davydov is now an assistant professor in the Department of Mechanical Engineering at Rice University, where he continues to pursue research in the reliable control of engineering systems.
Established in honor of Winifred and Louis Lancaster, the annual dissertation awards recognize two doctoral-degree recipients, or candidates, from a broad, rotating group of academic areas. Recipients are selected for dissertations deemed to have significant impact on their fields.