SPEAKER: Abraham I. Harte (AEI)
ABSTRACT: How do nonlinear gravitational waves differ from their linearized counterparts? Locally, they’re almost identical. Clock comparisons/redshifts, light deflections, and other potential observables are not local, however. This talk discusses how geometric optics is affected by nonlinear plane waves. Higher-order effects generically grow rapidly with the source-observer separation, and the linear theory is found to fail completely on very large scales. Also, nonlinear effects in GR can mimic the existence of a third gravitational wave polarization mode.