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IMRPhenom tidal utils

Small utility script for shared functions between tidal waveforms, especially for NRTidalv2

Functions:

Name Description
get_kappa

Computes the tidal deformability parameter kappa according to equation (8) of the NRTidalv2 paper.

get_quadparam_octparam

Compute the quadrupole and octupole parameter by checking the value of lambda and choosing the right subroutine.

get_quadparam_octparam_eos

Compute the quadrupole and octupole parameters using LAL's

universal_relation

Applies the general formula of a universal relationship, which is a quartic polynomial.

get_kappa(theta: Float[Array, 6]) -> FloatLike ¤

Computes the tidal deformability parameter kappa according to equation (8) of the NRTidalv2 paper.

Parameters:

Name Type Description Default
theta Array

Intrinsic parameters m1, m2, chi1, chi2, lambda1, lambda2

required

Returns:

Name Type Description
FloatLike FloatLike

kappa_eff^T from equation (8) of NRTidalv2 paper.

get_quadparam_octparam(lambda_: FloatLike) -> tuple[FloatLike, FloatLike] ¤

Compute the quadrupole and octupole parameter by checking the value of lambda and choosing the right subroutine. If lambda is smaller than 1, we make use of the fit formula as given by the LAL source code. Otherwise, we rely on the equations of the NRTidalv2 paper to get these parameters.

Parameters:

Name Type Description Default
lambda_ FloatLike

Tidal deformability of object.

required

Returns:

Type Description
tuple[FloatLike, FloatLike]

tuple[FloatLike, FloatLike]: Quadrupole and octupole parameters.

get_quadparam_octparam_eos(lambda_: FloatLike) -> tuple[FloatLike, FloatLike] ¤

Compute the quadrupole and octupole parameters using LAL's XLALSimInspiralEOSQfromLambda relation.

universal_relation(coeffs: Float[Array, 5], x: FloatLike) -> FloatLike ¤

Applies the general formula of a universal relationship, which is a quartic polynomial.

Parameters:

Name Type Description Default
coeffs Array

Array of coefficients for the quartic polynomial, starting from the constant term and going to the fourth order.

required
x FloatLike

Variable of quartic polynomial

required

Returns:

Name Type Description
FloatLike FloatLike

Result of universal relation