We compare the wavetrain from the QE approximation with the exact integrated solution. The initial radius of the shell is R=8M0, corresponding to a moderately strong gravitational field.
|
The QE approximation shows remarkable agreement with the exact, integrated solution. Here we compare the two approaches by plotting the energy and gravitational luminosity as a function of apocenter radius.
|
A comparison of the actual gravitational wavetrains for the exact integrated solution and the QE approximation are very similar:
![]() |
![]() |
![]() |
The above pictures compare blowups of the wavetrains at three different times.
|
We also compare the exact integrated solution to the "monopole formula." The monopole approximation is given by the equation in the top panel.

At 8M0, corresponding to a moderately strong field, the monopole approximation breaks down. Here we see that the monopole approximation keeps phase coherence, but amplitude and shape do not match the exact wavetrain.
![]() |
![]() |
![]() |
Above we compare the monopole approximation with the exact, integrated solution at three different times.