Freese has contributed to early research on dark matter and dark energy. She was one of the first to propose ways to discover dark matter. Her idea of indirect detection in the Earth is being pursued by the IceCube Neutrino Observatory experiment, and the "wind" of dark matter particles felt as the Earth orbits the Milky Way is being searched for in worldwide experiments. Her work decisively ruled out MACHO dark matter in favor of WIMPs. She has proposed a model known as "Cardassian expansion," in which dark energy is replaced with a modification of Einstein's equations. Recently she proposed a new theoretical type of star, called a dark star, powered by dark matter annihilation rather than fusion. Freese has also worked on the beginnings of the universe, including the search for a successful inflationary theory to kick off the Big Bang. Her natural inflation model is a theoretically well-motivated variant of inflation; it uses axionic-type particles to provide the required flat potentials to drive the expansion. In 2013, observations made by the European Space Agency's Planck Satellite show that the framework of natural inflation matches the data. She has studied the Ultimate fate of the universe, including the fate of life in the universe." Freese has served on the Board of the Kavli Institute for Theoretical Physics in Santa Barbara and the Board of the Aspen Center for Physics. From 2008-2012 she was a Councilor and Member of the Executive Committee of the American Physical Society, and from 2005-2008 she was a member of the Astronomy and Astrophysics Advisory Committee. Currently she serves on the Board of the Oskar Klein Centre for Cosmoparticle Physics in Stockholm.
Freese was born in Freiburg, Germany, to Ernst Freese and Elisabeth Bautz Freese. At age nine months she emigrated to the United States. From her ten year marriage to Fred Adams she has a son, Douglas Quincy Adams. Her brother Andrew Freese, Chief of Neurosurgery at Brandywine Hospital, resides in Chester Springs, PA. Her uncle Ekkehard Bautz, now retired, was a molecular biologist and chair of the Institute of Molecular Genetics at the University of Heidelberg. Her cousin :de:Anja Freese|Anja Freese, a German actor, currently resides in Los Angeles.
Popular science
Freese has written a review for the general educated public on dark matter and energy as they relate to recent research in cosmology and particle physics, titled The Cosmic Cocktail: Three Parts Dark Matter. The book is partly autobiographical. She covers the contributions of Fritz Zwicky, for example, who was recently profiled as "the most important astronomer you've never heard of" and "the father of dark matter" on.