Tests of relativity by complementary rotating Michelson-Morley experiments.

We report relativity tests based on data from two simultaneous Michelson-Morley experiments, spanning a period of more than 1 yr. Both were actively rotated on turntables. One (in Berlin, Germany) uses optical Fabry-Perot resonators made of fused silica; the other (in Perth, Australia) uses microwave whispering-gallery sapphire resonators. Within the standard model extension, we obtain simultaneous limits on Lorentz violation for electrons (5 coefficients) and photons (8) at levels down to 10(-16), improved by factors between 3 and 50 compared to previous work.

Test of the isotropy of the speed of light using a continuously rotating optical resonator.

We report on a test of Lorentz invariance performed by comparing the resonance frequencies of one stationary optical resonator and one continuously rotating on a precision air bearing turntable. Special attention is paid to the control of rotation induced systematic effects. Within the photon sector of the standard model extension, we obtain improved limits on combinations of 8 parameters at a level of a few parts in 10(-16). For the previously least well known parameter we find [EQUATION: SEE TEXT]. Within the Robertson-Mansouri-Sexl test theory, our measurement restricts the isotropy violation parameter [EQUATION: SEE TEXT]. corresponding to an eightfold improvement with respect to previous nonrotating measurements.