Theory and Phenomenology of Einstein Equivalence Principle Violations

Embry-Riddle Aeronautical University, Daytona Beach FL

Investigators

Abstract

Quantum physics and Einstein's General Relativity (GR) describe nearly all known physics quite successfully. However, physicists conjecture that there exists a theory of everything that would unify these two theories. One popular approach of late is to identify features of such a unified theory that could result in experimental signatures or evidence of new physics in sensitive experiments and observations. Fundamental principles of GR such as the lack of any special direction in space (isotropy of space) could be violated in proposals for a unified theory of physics. The PI will investigate new types of signals for the breaking of isotropy of space that could be measured in sensitive observations of astrophysical systems like pulsars and measurements of the ripples in spacetime known as gravitational waves. This award will support undergraduate research opportunities in theoretical physics. The Einstein Equivalence Principle (EEP), a vital foundation of GR, includes the spacetime symmetry called local Lorentz symmetry. Some candidate models of quantum gravity contain the possibility that minuscule violations of spacetime symmetry may occur in nature. Generic violations of spacetime symmetry are described using an effective field theory framework. The PI will study the effective field theory framework, seeking solutions for signals for spacetime-symmetry violations in gravitational wave observations and other astrophysical systems like pulsars. Researchers involved in precision tests of GR, in particular gravitational wave tests, will find motivation and additional areas in which to search for novel effects and new physics beyond GR. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.