Cavity Bounds on Higher-Order Lorentz-Violating Coefficients
  We determine the sensitivity of a modern Michelson-Morley resonant-cavity experiment to the higher-order nonbirefringent and nondispersive coefficients of the Lorentz-violating Standard-Model Extension. Data from a recent year-long run of the experiment is used to place the first bounds on these coefficients. 
Stephen R. Parker, Matthew Mewes, Michael E. Tobar, Paul L. Stanwix
hep-ph gr-qc