Hirosi Ooguri, the Fred Kavli Professor of Theoretical Physics and Mathematics at Caltech, will take on the role of head of the Division of Physics, Mathematics and Astronomy (PMA) starting on August 16, 2025. Ooguri, who has been the director of the Walter Burke Institute for Theoretical Physics since its inception in 2014, is a prominent theorist in string theory, which seeks to reconcile the fundamental laws of subatomic particles with gravitational laws on a larger scale. His research has yielded significant insights into topics such as black holes, particle physics, dark energy, and sophisticated mathematical theories.
“I’m thrilled that Hirosi has chosen to step into the role of division chair,” remarks Caltech Provost David A. Tirrell. “Hirosi is an eminent scientist and an exceptional educator whose endeavors encompass a wide array of inquiries that define our Division of Physics, Mathematics and Astronomy.”
Ooguri earned his bachelor’s degree from Kyoto University in 1984 and obtained his PhD from the University of Tokyo in 1989. He became a member of the Caltech faculty in 2000. Among numerous accolades, Ooguri has been awarded the Medal of Honor with Purple Ribbon by the emperor of Japan and the Eisenbud Prize for Mathematics and Physics from the American Mathematical Society. He is a fellow of the American Academy of Arts and Sciences and the American Mathematical Society. Ooguri’s widely read popular science books have surpassed 400,000 copies in sales, and his Introduction to Superstring Theory received the 2014 Kodansha Prize for Science Books. He also acted as a science advisor for a three-dimensional dome film produced by Japan’s National Museum of Emerging Science and Innovation.
Beyond his contributions to Caltech, Ooguri played a key role in establishing the Kavli Institute for the Physics and Mathematics of the Universe at the University of Tokyo in 2007, where he served as director from 2018 to 2023. Additionally, he has held the position of president (2016 to 2019) and board chair (2021 to 2024) at the Aspen Center for Physics.
“Over the last 25 years, Caltech has been instrumental in fostering my research and teaching, allowing me to develop professionally within this extraordinary academic setting,” Ooguri shares. “Although the future may present challenges, I am committed to doing my utmost to help us become even stronger.”
Ooguri takes over from Fiona Harrison, the Harold A. Rosen Professor of Physics, currently holding the Kent and Joyce Kresa Leadership Chair of the PMA division. Harrison has been the PMA chair for the past ten years, during which she oversaw the hiring of 20 faculty members, transformed the former Sloan Laboratory into Linde Hall, relocated the American Institute of Mathematics (AIM) to Caltech Hall, and initiated construction on the Ginsburg Center for Quantum Precision Measurement. During Harrison’s tenure, the Brinson Exploration Hub was established, funding was secured for new astronomy instruments, and Caltech researchers made numerous discoveries, including the first direct detection of ripples in space-time known as gravitational waves in 2015—a finding for which, in 2017, two Caltech professors were awarded the Nobel Prize in Physics.
Throughout her tenure as chair, Harrison also acted as the principal investigator for two NASA missions: the ongoing NuSTAR mission, an X-ray telescope investigating the mysteries of black holes, and the UVEX mission, aiming to survey stars and galaxies using ultraviolet light.
“Fiona has demonstrated exceptional leadership for the PMA division over the past decade,” Tirrell states. “Her insight, vision, and sound judgment have transformed the faculty, improved its physical facilities, and enriched its educational and research programs.”
Ooguri remarks, “I am privileged to follow in Fiona Harrison’s footsteps and thankful for the chance to serve Caltech in this new capacity.”