What is the universe made of? What is dark matter and dark energy? What makes the universe accelerate—both now and during the rapid expansion that occurred moments after the Big Bang?

Katherine Freese, astrophysics professor and director of the Weinberg Institute for Theoretical Physics at the University of Texas, Austin, will explore these questions at the University of Utah’s Frontiers of Science lecture series on Wednesday, Dec. 3, at 6:30 p.m.

Freese’s work in theoretical cosmology is at the interface of astrophysics and particle physics, a field of study that has seen remarkable advances in the past decade.

“For [years] I've had strong connections to the University of Utah and am excited to visit and give the Frontiers of Science Lecture,” said Freese, who will present in the auditorium of the new L. S. Skaggs Applied Science Building. Freese credits the concept of dark stars, stars made of ordinary matter but powered by dark matter, to the work of U physics professor Paolo Gondolo, as well as UC Santa Cruz graduate student Doug Spolyar.

For the past 15 years, Freese has also worked on many projects with particle physicist Pearl Sandick, who is the interim dean of the U’s College of Science. Freese, Sandick and others are working beyond the Standard Model of particle physics, addressing one of cosmology’s most profound puzzles: understanding what the universe is actually made of. The ordinary atoms in our bodies, air, planets and stars make up only 5% of the universe. The remaining 95% is a cosmic recipe of 25% dark matter and 70% dark energy—both invisible and still mysterious.

At the Frontiers of Science lecture, Freese will trace the dark matter puzzle from visionary 1930s scientists who first proposed it, to Vera Rubin's 1970s observations that proved its dominance in galaxies, to today's cutting-edge experiments in underground labs, space satellites and the Large Hadron Collider. Freese will also share the evidence for dark matter and discuss dark stars that may have already been spotted by the James Webb Space Telescope. Solving this mystery will mark a defining moment in our quest to understand the universe.

Frontiers of Science will be followed by a reception and star party at the rooftop Willard Eccles Astronomy Observatory, which now hosts public star parties every Wednesday (weather permitting).

Frontiers of Science event details

Wednesday, Dec. 3, 2025 | 6:30 p.m.
L. S. Skaggs Applied Science Building, University of Utah
275 S. University Street, Salt Lake City

About Katherine Freese

Katherine Freese is the director of the Weinberg Institute for Theoretical Physics as well as the Jeff & Gail Endowed Chair of Physics at the University of Texas, Austin. She is also a guest professor of physics at Stockholm University, where she received a $13 million grant over 10 years (2014-2024) for research in cosmoparticle physics. She served as director of NORDITA, the Nordic Institute for Theoretical Physics, from 2014 to 2016. She is the author of the book, "The Cosmic Cocktail: Three Parts Dark Matter," published in June 2014 by Princeton University Press.

For more information about Freese, visit katherinefreese.com.

About the Frontiers of Science Lecture Series

The Frontiers of Science lecture series was established in 1967 by University of Utah alumnus and physics professor Peter Gibbs. By 1970, the University had hosted 10 Nobel laureates for public Frontiers lectures. By 1993, when Gibbs retired, the Frontiers organizers had hosted another 20 laureates. Today, Frontiers of Science is the longest continuously-running lecture series at the University of Utah.

For more information about Frontiers of Science, visit science.utah.edu/events/frontiers-of-science.