IMRPhenom tidal utils
ripplegw.waveforms.IMRPhenom_tidal_utils
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Small utility script for shared functions between tidal waveforms, especially for NRTidalv2
universal_relation(coeffs: Float[Array, 5], x: Float)
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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
|
Float
|
Variable of quartic polynomial |
required |
Returns:
| Name | Type | Description |
|---|---|---|
Float |
Result of universal relation |
get_quadparam_octparam(lambda_: Float) -> tuple[Float, Float]
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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_
|
Float
|
Tidal deformability of object. |
required |
Returns:
| Type | Description |
|---|---|
tuple[Float, Float]
|
tuple[Float, Float]: Quadrupole and octupole parameters. |
_get_quadparam_octparam_low(lambda_: Float) -> tuple[Float, Float]
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Computes quadparameter following LALSimUniversalRelations.c of lalsuite
Version for lambdas smaller than 1.
LALsuite has an extension where a separate formula is used for lambdas smaller than one, and another formula is used for lambdas larger than one. Args: lambda_: tidal deformability
Returns:
| Name | Type | Description |
|---|---|---|
quadparam |
Float
|
Quadrupole coefficient called C_Q in NRTidalv2 paper |
octparam |
Float
|
Octupole coefficient called C_Oc in NRTidalv2 paper |
_get_quadparam_octparam_high(lambda_: Float) -> tuple[Float, Float]
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Computes quadparameter, following LALSimUniversalRelations.c of lalsuite
Version for lambdas greater than 1.
LALsuite has an extension where a separate formula is used for lambdas smaller than one, and another formula is used for lambdas larger than one. Args: lambda_: tidal deformability
Returns:
| Name | Type | Description |
|---|---|---|
quadparam |
Float
|
Quadrupole coefficient called C_Q in NRTidalv2 paper |
octparam |
Float
|
Octupole coefficient called C_Oc in NRTidalv2 paper |
get_kappa(theta: Array) -> Float
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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 |
|---|---|---|
Float |
Float
|
kappa_eff^T from equation (8) of NRTidalv2 paper. |