#2160: QuasiLocalMeasures qlm_spin doesn't work for spins not aligned along the z axis ---------------------------------+----------------------------------- Reporter: sbozzolator@… | Type: defect Status: new | Priority: unset Milestone: | Component: EinsteinToolkit thorn Version: development version | Keywords: QuasiLocalMeasures ---------------------------------+----------------------------------- Einstein Toolkit version: `ET_2018_02`.
Parameter file: `qc0-mclachlan.par` in einsteinexamples with the additional parameter `TwoPunctures::par_S_plus [0] = +0.3`
Problem: The diagnostic `qlm_spin[0]` returns a spin of 0, whereas the expected one should be 0.3.
If instead of `TwoPunctures::par_S_plus [1] = +0.3` one sets `TwoPunctures::par_S_plus [2] = +0.3`, `qlm_spin[0]` is correctly outputting 0.3
This happens because QuasiLocalMeasures finds in both cases the rotational Killing vector d/dphi (as seen setting `QuasiLocalMeasures::veryverbose = yes`), which is correct in the second case (when the axis aligned with the z-direction), but doesn't sound right when the rotation is with respect to the x-axis.
Changing `QuasiLocalMeasures::killing_vector_method` to `axial` or `gradient` does not change the outcome.
Best regards, Gabriele