Spin-induced quadrupole moment analysis LALSuite review branch

Description

Spinning compact objects get deformed due to their own spins leading to quadrupole and higher multipole moments. These moments get encoded in the post-Newtonian gravitational waveforms through the spin terms at different PN orders. In the state of art PN spinning waveform, Spin-induced quadrupole appears at 2PN and 3PN in LALSimulation. If the compact object is a BH, the multipole moments should be given by no-hair conjecture. Hence by accurately measuring this effect, we can test whether the high mass compact binaries we have detected so far are indeed BHs and hence constrain the allowed parameter space for BH mimickers.

We make modifications to sample {dQuadMon1, dQuadMon2} (spin-induced quadrupole moment parameters) and their symmetric and anti-symmetric combinations {dQuadMonS, dQuadMonA} to LALInference and introduced them to the post-processing scripts.

Review wiki page link

Main modifications are applied to:

• LALInference codes:

  • LALInference.c
  • LALInference.h
  • LALInferenceInitCBC.c
  • LALInferenceTemplate.c
  • LALInferenceProposal.c

• Post-processing:

  • cbcBayesCompPos.py
  • cbcBayesPPAnalysis.py
  • bayespputils.py

• LALSimulation:

  • LALSimInspiralTestGRParams
    • Adding the extra parameters to XLALSimInspiralWaveformParamsNonGRAreDefault(LALDict *params) L232-233

API Changes and Justification

Backwards Compatible Changes

• This change introduces no API changes
• This change adds new API calls

Backwards Incompatible Changes

• This change modifies an existing API
• This change removes an existing API

If any of the Backwards Incompatible check boxes are ticked please provide a justification why this change is necessary and why it needs to be done in a backward-incompatible way.

Review Status

• Review wiki-page:https://git.ligo.org/nv.krishnendu/lalsuite/-/wikis/Home
• Review statement: https://git.ligo.org/nv.krishnendu/lalsuite/-/wikis/Review-Statement