Gravity Seminars

The gravitational wave memory effect that manifests itself as a permanent distortion of space after a gravitational wave burst, is a prediction of GR, whose detection is expected to be around the corner. In this talk, I will present recent work, in which the memory effect of a broad class of beyond GR metric theories of gravity is shown to be modified primarily through the presence of additional propagating modes in the theory. This strongly suggests the possibility of using memory observations as a model independent test of the number of dynamical gravitational degrees of freedom. Such a general statement rests upon a reinterpretation of the memory effect as naturally arising within the broadly applicable Isaacson approach to gravitational waves.