/EMRI_Kludge_Suite

Primary LanguageC++

EMRI Kludge Suite

Version 0.2.0

This is a C/C++ suite that allows kludge waveforms for extreme-mass-ratio inspirals (EMRIs) to be generated with shared settings and parameters. The three waveforms included in the suite are the augmented analytic kludge (AAK) [1,2], the analytic kludge (AK) [3], and the numerical kludge (NK) [4].

Running make will create the corresponding executables in the folder ./bin:

  • AAK_Waveform
  • AK_Waveform
  • NK_Waveform

The file ./SetPar_Template is a template for a formatted settings/parameters file that contains the output file path, various toggles, and the EMRI parameters. More details are provided in the template file itself.

As an example, running

bin/AAK_Waveform SetPar_Template

will generate an AAK waveform with default settings and parameters. Three files will be created in ./bin:

  • example_wave.dat contains waveform data (t, h_I, h_II)
  • example_traj.dat contains inspiral trajectory data (t, p/M, e, iota, E, L_z, Q)
  • example_info.txt contains additional information such as signal-to-noise ratio and waveform timing

NEW IN VERSION 0.2.0: Automated backward integration for plunging orbits; adaptive fitting duration; improved speed and robustness.

Please check https://github.com/alvincjk/EMRI_Kludge_Suite for any version updates.

— Alvin Chua, Dec 2017

Work in progress

  • Suite utilities to compute waveform matches, Fisher matrices, etc. may be included in the future

List of (important) known bugs

  • The LISA response functions h_I/h_II for the AAK/AK and the NK do not match up, likely due to differing conventions when implementing the Doppler shift
  • The NK may produce NaNs at times that coincide with specific fractions of the LISA orbital period (when using integer values of dt), or near plunge; this needs to be fixed, but in the meantime a band-aid solution for dealing with isolated NaNs is included
  • All waveforms may have difficulties with zero or epsilon values for certain parameters such as spin, eccentricity and inclination

Authors

Alvin Chua
Jet Propulsion Laboratory alvin.j.chua@jpl.nasa.gov

Jonathan Gair
School of Mathematics, University of Edinburgh j.gair@ed.ac.uk

The EMRI Kludge Suite is also based on code written by Leor Barack (for the AK) and Scott Hughes (for the NK).

References

[1] A. J. K. Chua & J. R. Gair. Improved analytic extreme-mass-ratio inspiral model for scoping out eLISA data analysis. Class. Quantum Grav. 32:232002, 2015.

[2] A. J. K. Chua, C. J. Moore & J. R. Gair. Augmented kludge waveforms for detecting extreme-mass-ratio inspirals. Physical Review D 96:044005, 2017.

[3] L. Barack & C. Cutler. LISA capture sources: Approximate waveforms, signal-to-noise ratios, and parameter estimation accuracy. Physical Review D 69:082005, 2004.

[4] S. Babak, H. Fang, J. R. Gair, K. Glampedakis & S. A. Hughes. "Kludge" gravitational waveforms for a test-body orbiting a Kerr black hole. Physical Review D 75:024005, 2007.