Astrophysics Theorist

Jonathan Arons

Professor Emeritus

Jonathan Arons earned his Ph.D. in Astronomy from Harvard in 1970. He was a postdoctoral fellow at the Princeton University Observatory in 1970-71, and at the Institute for Advanced Study in 1971-72. He joined the Astronomy Department at UC Berkeley in 1972, and the Physics Department in 1980. Fellowships and honors include: Woodrow Wilson and Danforth Graduate Fellowships, 1965-70; Guggenheim Fellowship, 1980; Miller Professorships, 1985-86 and 2002-03; elected as an APS Fellow in 1984. He currently serves as Executive Director of the Miller Institute and as Director of the Theoretical...

Raphael Bousso

Professor and The Chancellor's Chair in Physics

Raphael Bousso received his Ph.D. from Cambridge University in 1998 and went on to become a Postdoc at Stanford University. He also worked at the Kavli Institute for Theoretical Physics in Santa Barbara. In 2002/03 he was a fellow at the Harvard University physics department and the Radcliffe Institute for Advanced Study. In July 2003 he joined the physics department at UC Berkeley.

Research Interests

My interests are in theoretical cosmology and quantum gravity.

The central principles of quantum mechanics and of general relativity (our classical theory of gravity) come into...

Benjamin Safdi

Assistant Professor

Benjamin Safdi received his undergraduate degree from the University of Colorado at Boulder, a Master of Advanced Study from Cambridge University, as a Churchill Scholar, and his PhD from Princeton University in 2014. He was then a Pappalardo Fellow in physics at the Massachusetts Institute of Technology until 2017, when he started as an assistant professor at the University of Michigan, Ann Arbor. Dr. Safdi moved to LBNL in 2020 and then to UC Berkeley in 2021. He received the Department of Energy Early Career Award in 2018 and the IUPAP C11 Young Scientist Prize in Particles and Fields...

When is an aurora not an aurora?

December 8, 2023

"Steve" and "picket fence" in the night sky over Canada

The purple and white emissions at the top are referred to as "Steve," while the green emissions are called "picket fence." The rare phenomena, which are distinct from the typical aurora, often occur together and may be caused by similar conditions at the edge of space. The photo was taken looking south over Berg Lake toward Mt. Robson in the Canadian...

Closest supernova in a decade reveals how exploding stars evolve

August 29, 2023

Galaxies in space

The Pinwheel Galaxy, or Messier 101, on May 21, 2023, four days after the light from the supernova 2023ixf reached Earth.

Alex Filippenko is the kind of guy who brings a telescope to a party. True to form, at a soiree on May 18 this year, he wowed his hosts with images of star clusters and colorful galaxies — including the dramatic spiral Pinwheel Galaxy — and snapped...

Christopher McKee

Professor Emeritus

Chris McKee received his Ph.D. in Physics from UC Berkeley in 1970. After a brief stay at Lawrence Livermore National Laboratory, he spent a year as a postdoc at Caltech. He then went to Harvard as an assistant professor of astronomy for three years, and in 1974 he joined the Physics and Astronomy Departments here at Berkeley. He served as the first Director of the Theoretical Astrophysics Center in 1985, and from 1985-1998 he directed the Space Sciences Laboratory. He was the Henry Norris Russell Lecturer of the American Astronomical Society in 2016 and appointed a Legacy...

Dan Kasen


Prof. Kasen received his B.S. from Stanford University and his M.S. and Ph.D. in physics from UC Berkeley. Prior to returning to Cal, he was the Alan C. Davis fellow at Johns Hopkins University and a Hubble fellow at UC Santa Cruz. He joined the Berkeley physics faculty in 2010, jointly appointed with the nuclear science division at LBNL.

Liang Dai

Assistant Professor and The Michael M. Garland Chair in Physics

Prof. Dai received a B.S. in Physics from Peking University in 2011. Later on, he earned his Ph.D. in Physics from the Johns Hopkins University in 2015 working on theoretical cosmology. From 2015 to 2018, he was awarded an NASA Einstein fellowship and was appointed a postdoctoral Member at the Institute for Advanced Study in the School of Natural Sciences. From 2018 to 2020, he was a long-term John Bahcall postdoctoral fellow at the Institute for Advanced Study, before he joined the faculty in the Department of Physics at the University of California, Berkeley.

Research Interests


M87 in 3D: New view of galaxy helps pin down mass of the black hole at its core

April 13, 2023

Image of a galaxy with a wire grid shape over it illustrating the M87 galaxy

Seen from Earth, the giant elliptical galaxy M87 is just a two-dimensional blob, though one that appears perfectly symmetrical and thus a favored target of amateur astronomers.
Yet, a new, highly detailed analysis of the motion of stars around its central supermassive black hole — the first black hole to be imaged by the Event Horizon Telescope...

Bright gamma ray burst confounds models of black hole birth

March 28, 2023

Diagram of a gamma ray emission emerging from a black hole showing the different types of energy in the afterglow

Last October, following one of the brightest flashes of gamma rays ever observed in the sky, telescopes around the world captured a wealth of data from an event that is thought to herald the collapse of a massive star and the birth of a black hole.

But that fire hose of data demonstrated clearly that...