Risa H. Wechsler

Biosketch

Risa Wechsler is a theoretical cosmologist recognized for her work on the nature of dark matter and dark energy, the formation and evolution of galaxies, and the growth of cosmic structure. Wechsler is the Humanities and Sciences Professor at Stanford University, where she is also Director of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) and the Center for Decoding the Universe. She earned her SB in Physics from the Massachusetts Institute of Technology in 1996 and her PhD in Physics from the University of California, Santa Cruz in 2001, followed by postdoctoral fellowships at the University of Michigan and the University of Chicago. She joined the faculty at Stanford in 2006, and holds appointments in the Stanford Department of Physics and in the Department of Particle Physics & Astrophysics at SLAC National Accelerator Laboratory. Wechsler is a member of the National Academy of Sciences and the American Academy of Arts and Sciences and a Fellow of the American Physical Society and the American Association for the Advancement of Science. She has served on advisory committees for the NAS, the Department of Energy, the National Science Foundation, NASA, and several foundations, and is currently on the boards of the Aspen Center for Physics and the LSST Discovery Alliance. She is committed to public engagement with science and has shared her work in venues including TED, Teen Vogue, PBS, and the BBC.

Research Interests

Dr. Wechsler’s research seeks to understand the fundamental physics that shapes the universe, focusing on the nature of dark matter and dark energy and the processes that govern the formation and evolution of galaxies within the growth of cosmic structure. She develops and applies large cosmological simulations and theoretical models in tandem with the most ambitious galaxy surveys to test cosmological models and reveal the physical connection between galaxies and their dark matter halos. Her work has illuminated the growth of structure across cosmic time, the properties of the Milky Way in its cosmological context, and the imprint of dark matter on small-scale structure. She has played leadership roles in several of the largest cosmic surveys including the Dark Energy Survey, the Dark Energy Spectroscopic Instrument, and the Vera Rubin Observatory’s Legacy Survey of Space and Time, which together are providing unprecedented maps of the universe and its evolution. She is currently particularly interested in using the smallest observable cosmic structures to understand the physics of dark matter and the limits of galaxy formation. Her group has developed many widely used tools and methods for cosmological simulations, and is currently employing new methods at the intersection of astrophysics, AI/ML, and data science to accelerate discovery in the era of massive datasets.