Welcome

The Kavli Institute for Particle Astrophysics and Cosmology, or KIPAC, was inaugurated in 2003 as an independent laboratory of Stanford University to serve as a bridge between the disciplines of astrophysics, cosmology and particle physics. KIPAC's members work in the Physics and Applied Physics Departments on the Stanford campus and at the SLAC National Accelerator Laboratory. Its mission is to bring the resources of modern computational, experimental, observational and theoretical science to bear on our understanding of the universe at large.

KIPAC Annual Reports

Research Highlights

Jun 6, 2018 | From the tiny to the astronomical: Massive neutrinos and cosmology

Some phenomena affected by cosmic neutrinos (left to right): CMB, the clustering of dark matter, and the clustering of galaxies at low red-shift. (Credit: WMAP, SDSS.)

While neutrinos were hypothesized by Wolfgang Pauli back in 1930, they remain among the most mysterious particles within the Standard Model of particle physics. We now know that there are three types of neutrinos, and neutrino oscillation experiments have shown that there are at least two types which have mass. Current experiments have not yet been able to nail down the precise masses of the three neutrinos, but have placed upper bounds on sum of their masses. These upper bounds tell us that neutrinos have to be the lightest of all Standard Model particles, more than six orders of magnitude lighter than the electron!

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