Key points are not available for this paper at this time.
A test of Lorentz invariance for electromagnetic waves was performed by comparing the resonance frequencies of two optical resonators as a function of orientation in space. In terms of the Robertson-Mansouri-Sexl theory, we obtain --1∕2= (+0. 530. 7) 10^-10, a tenfold improvement compared to the previous best results. We also set a first upper limit for a parameter of the standard model extension test theory, ({ { \~{}}₄-) }^ZZ<210^-14.
Antonini et al. (2005) studied this question.