Institute, founded 2007
Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU)
Kavli IPMU at the University of Tokyo blends physics, astronomy and math to study the universe. It led development of Subaru's Prime Focus Spectrograph.
- Location
- University of Tokyo Kashiwa Campus, Kashiwa, Chiba
- Focus
- Cosmology, Dark matter, Dark energy, Galaxies, Telescopes and missions
- Coordinates
- 35.902, 139.938
The Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), on the University of Tokyo’s Kashiwa campus, was created on October 1, 2007, by founding director Hitoshi Murayama under Japan’s World Premier International Research Center Initiative. It took its current name in 2012 after an endowment from the Kavli Foundation. Its members, who include Nobel laureate Takaaki Kajita, mix physics, astronomy and mathematics around five questions: how the universe began, how it will end, what it is made of, what laws govern it, and why we exist.
Flagship projects
- Prime Focus Spectrograph (PFS): Kavli IPMU led the proposal and development of this 2,400-fiber spectrograph for the Subaru Telescope, which began science operations in February 2025.
- LiteBIRD: a JAXA-led space mission to map the polarization of the cosmic microwave background, in which Kavli IPMU takes part.
Recent results
On August 7, 2026, Kavli IPMU reported that LiteBIRD passed its Mission Definition Review #2 and is moving toward Phase A. The mission’s main goal is to test cosmic inflation by searching for B-mode polarization, a twisting pattern in the microwave background that primordial gravitational waves would leave. That signal would be a faint layer on top of the microwave background whose temperature pattern Planck measured precisely.
PFS, meanwhile, puts Japan into the same class of survey spectroscopy as DESI, whose 2025 results hint that dark energy may be evolving.
What to watch, 2026-2030
- 2025-2030: the PFS Subaru Strategic Program, 360 nights over about five years.
- LiteBIRD’s progress through Phase A after its 2026 review.
Why scientists are converging here
The biggest open questions in cosmology, what dark matter is, why expansion is accelerating and whether inflation happened, need physicists, astronomers and mathematicians in the same building. Kavli IPMU was designed around that idea, and with PFS running and LiteBIRD advancing, its projects span both the universe’s first instant and its present-day structure.