Violations of Lorentz invariance in the form of a frame dependence of the speed of light is forbidden by most of modern physics. However, this law is increasingly coming under pressure from theories such as string theory and theories of quantum gravity, which predict violations of Lorentz invariance at some level. This paper presents a concept for a Lorentz invariance test using electromagnetically induced transparency, which, in combination with an effect known as Fresnel drag, can amplify the effect of variations of the speed of light. It is shown how a model apparatus could, in principle, be used to search for frame dependencies in the speed of light to a sensitivity of a part in 1021. It is shown that, counter-intuitively, in testing relativistic time dilation, the speed of the particle is not the most important feature and that the test can be performed for relatively small velocities.
Acknowledgments
This work was supported by a Seed Core grant (FD327) from the Particle Peer Review Panel of the Particle Physics and Astronomy Research Council. I would also like to thank J. Cotter for useful input and skeptical comment.