Interferometric Constraints on Spacelike Coherent Rotational Fluctuations

Precision measurements are reported of the cross-spectrum rotationally induced differential position displacements in a pair colocated 39 m long, high-power Michelson interferometers. One arm each interferometer is bent 90\ifmmode^\circ\else\textdegree\fi{} near its midpoint to obtain sensitivity rotations about an axis normal plane instrument. The instrument achieves quantum-limited sensing spatially correlated signals broad frequency band extending beyond 3.9-MHz inverse light travel time apparatus. For stationary with bandwidth $\mathrm{\ensuremath{\Delta}}f>10\text{ }\text{ }\mathrm{kHz}$, rotation-induced strain $h$ classical or exotic origin surpasses ${\mathrm{CSD}}_{\ensuremath{\delta}h}<{t}_{P}/2$, where ${t}_{P}=5.39\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}44}\text{ }\mathrm{s}$ Planck time. This measurement used constrain semiclassical model nonlocally coherent rotational degrees freedom spacetime, which have been conjectured emerge holographic quantum geometry but not present metric.