Testing Local Lorentz Invariance using laboratory and space technology

Abstract

We present a theoretical framework for discussing experimental tests of Local Lorentz Invariance. In contrast to earlier kinematical approaches to tests of special relativity, this framework is dynamical in nature. Based on a formalism for analyzing non-metric theories of gravity, it treats in detail the behavior of rods, clocks, and other devices in motion relative to any preferred universal frame singled out by Lorentz non-invariant dynamics. Observable deviations from Lorentz invariance are determined by the size of a parameter δ ≡ ( c −2 − 1), where c is the speed of light in the preferred frame relative to the limiting speed of test particles. If Lorentz invariance holds, δ = 0. Previous tests of local lorentz invariance have set such upper limits as |δ| < 10 −4 (Michelson-Morley experiment), |δ| < 10 −16 (Hughes-Drever experiment), and |δ| < 3 × 10 −22 (trapped atoms experiments). We describe new tests, involving atomic clocks and the NASA Deep Space Network, and involving gyroscopes, and discuss the possible constraints they would provide.