LALSimulation  5.4.0.1-fe68b98
lalsimulation.nrfits.pn_spin_evolution_wrapper Namespace Reference

Functions

def spin_evolution (q, chiA0, chiB0, omega0, approximant='SpinTaylorT4', dt=0.1, spinO=6, phaseO=7)
 Wrapper for PN spin and dynamics evolution in LAL. More...
 

Function Documentation

◆ spin_evolution()

def lalsimulation.nrfits.pn_spin_evolution_wrapper.spin_evolution (   q,
  chiA0,
  chiB0,
  omega0,
  approximant = 'SpinTaylorT4',
  dt = 0.1,
  spinO = 6,
  phaseO = 7 
)

Wrapper for PN spin and dynamics evolution in LAL.

Inputs:

  • q: Mass ratio (q>=1)
  • chiA0: Dimensionless spin of BhA at initial freq.
  • chiB0: Dimensionless spin of BhB at initial freq.
  • omega0: Initial orbital frequency in dimensionless units.
  • approximant: 'SpinTaylorT1/T4/T5'. Default: SpinTaylorT4.
  • dt: Dimensionless step time for evolution. Default: 0.1
  • spinO: Twice PN order of spin effects. Default: 7.
  • phaseO: Twice PN order in phase. Default: 7.

Outputs (all are time series):

  • Omega: Dimensionless orbital frequency.
  • Phi: Orbital phase (radians)
  • ChiA: Dimensionless spin of BhA
  • ChiB: Dimensionless spin of BhB
  • LNhat: Orbital angular momentum direction
  • E1: Orbital plane basis vector

The frame is defined at the initial frequency omega0, as follows:

  • z-axis is set by the orbital angular momentum direction.
  • x-axis is the separation vector from the lighter BH to the heavier BH.
  • y-axis completes the triad by right-hand rule.
    All quantities are defined in this fixed frame, including initial spins, returned spins, other vectors like LNhat, etc.

Definition at line 32 of file pn_spin_evolution_wrapper.py.