College of Arts and Sciences

Gravitational Physics and Cosmology

Gravitational Physics

To date, Einstein’s General Theory of Relativity is the best current fundamental theory of gravity. This fascinating theory describes gravity as the curvature of space and time itself. As esoteric as it sounds, results from Einstein’s theory are put to use every day in high-precision Global Positioning System (GPS) navigation.

Researchers in gravitational physics are exploring a wide range of applications of Einstein’s theory of gravity. Many physicists are interested in testing predictions of Einstein’s theory of gravity. One such prediction is that the universe is filled with gravitational waves: undulations in the fabric of spacetime. These waves are produced by enormous astrophysical events, such as the collision of two neutron stars or black holes. Gravitational waves are very weak and difficult to detect, and so dedicated collaborations exist to detect them including the Laser Interferometer Gravitational Wave Observatory (LIGO) collaboration.

Physicists are also interested in testing General Relativity and its foundations, Special Relativity and the Weak Equivalence Principle. One motivating idea is that tiny deviations from the principles of General Relativity might arise from a much sought after unified theory of physics that incorporates Einstein’s General Relativity and Quantum Mechanics. Gravitational physics offers unique testing grounds such as Earth-laboratory tests like gravimeter tests and short-range gravity tests as well as space-based tests such as lunar laser ranging, orbiting gyroscopes (Gravity Probe B), binary pulsar tests, and others.


Cosmology is the study of the evolution of the universe as a whole from the very early universe (Big Bang) to the present. Evidence for the standard cosmological model (called ΛCDM) that is widely accepted today has been accumulating since Edwin Hubble’s discovery that the universe is expanding in the 1920s.

With the discovery in the 1960s of the relic radiation from the Big Bang, called the Cosmic Microwave Background Radiation (CMBR), the Big Bang theory became widely accepted. In the last 20 years cosmology has become an exact science, thanks to precision measurements of the CMBR by the COBE and WMAP satellites as well as a host of other astrophysical observations including supernovae red shift studies. We now know the age of the universe to within 1%, that the universe is made up of mostly mysterious dark matter and dark energy, and that it will likely expand forever. The ΛCDM cosmological model is firmly based on Einstein’s famous General Theory of Relativity.


Michele Zanolin Dr. Michele Zanolin

Assistant Professor


Dr. Michele Zanolin’s research is in experimental general relativity within the LIGO Scientific Collaboration (LSC).

Andri Gretarsson Dr. Andri Gretarsson

Associate Professor


Dr. Andri Gretarsson works on LIGO, The Laser Interferometer Gravitational wave Observatory, among several other research projects pertinent to the College of Arts and Sciences.

Quentin Bailey Dr. Quentin Bailey

Associate Professor


Dr. Quentin Bailey is currently focused on the theoretical and experimental aspects of testing Lorentz symmetry, the spacetime symmetry of Special Relativity.

Brennan Hughey Dr. Brennan Hughey

Assistant Professor


With his eyes on all things astro, Dr. Brennan Hughey is doing ground-breaking research.