Utility functions¶
We here list and describe the utility functions and definitions provided in the WF4Py.WFutils module.
Convert between parameters¶
WF4Py provides some useful functions to convert between different parameters. All of them are vectorised, and can thus be used on arrays containing the parameters of multiple events.
Tidal deformability parameters¶
Conversions between the individual tidal deformabilities of the two objects \(\Lambda_1\) and \(\Lambda_2\) and the combinations \(\tilde{\Lambda}\) and \(\delta\tilde{\Lambda}\) (see the definition)
- WF4Py.WFutils.Lamt_delLam_from_Lam12(Lambda1, Lambda2, eta)[source]¶
Compute the dimensionless tidal deformability combinations \(\tilde{\Lambda}\) and \(\delta\tilde{\Lambda}\), defined in arXiv:1402.5156 eq. (5) and (6), as a function of the dimensionless tidal deformabilities of the two objects and the symmetric mass ratio.
- Parameters
Lambda1 (numpy.ndarray or float) – Tidal deformability of object 1, \(\Lambda_1\).
Lambda2 (numpy.ndarray or float) – Tidal deformability of object 2, \(\Lambda_2\).
eta (numpy.ndarray or float) – The symmetric mass ratio(s), \(\eta\), of the objects.
- Returns
\(\tilde{\Lambda}\) and \(\delta\tilde{\Lambda}\).
- Return type
tuple(numpy.ndarray, numpy.ndarray) or tuple(float, float)
- WF4Py.WFutils.Lam12_from_Lamt_delLam(Lamt, delLam, eta)[source]¶
Compute the dimensionless tidal deformabilities of the two objects as a function of the dimensionless tidal deformability combinations \(\tilde{\Lambda}\) and \(\delta\tilde{\Lambda}\), defined in arXiv:1402.5156 eq. (5) and (6), and the symmetric mass ratio.
- Parameters
Lamt (numpy.ndarray or float) – Tidal deformability combination \(\tilde{\Lambda}\).
delLam (numpy.ndarray or float) – Tidal deformability combination \(\delta\tilde{\Lambda}\).
eta (numpy.ndarray or float) – The symmetric mass ratio(s), \(\eta\), of the objects.
- Returns
\(\Lambda_1\) and \(\Lambda_2\).
- Return type
tuple(numpy.ndarray, numpy.ndarray) or tuple(float, float)
Masses¶
Conversions between the component masses and the chirp mass and symmetric mass ratio.
- WF4Py.WFutils.m1m2_from_Mceta(Mc, eta)[source]¶
Compute the component masses of a binary given its chirp mass and symmetric mass ratio.
- Parameters
Mc (numpy.ndarray or float) – Chirp mass of the binary, \({\cal M}_c\).
eta (numpy.ndarray or float) – The symmetric mass ratio(s), \(\eta\), of the objects.
- Returns
\(m_1\) and \(m_2\).
- Return type
tuple(numpy.ndarray, numpy.ndarray) or tuple(float, float)
- WF4Py.WFutils.Mceta_from_m1m2(m1, m2)[source]¶
Compute the chirp mass and symmetric mass ratio of a binary given its component masses.
- Parameters
m1 (numpy.ndarray or float) – Mass of the primary object, \(m_1\).
m2 (numpy.ndarray or float) – Mass of the secondary object, \(m_2\).
- Returns
\({\cal M}_c\) and \(\eta\).
- Return type
tuple(numpy.ndarray, numpy.ndarray) or tuple(float, float)
Constants¶
We here list the constants defined in the WF4Py.WFutils module
- WF4Py.WFutils.uGpc = 3.0856775814913673e+25¶
Gigaparsec (\(\rm Gpc\)) in meters (\(\rm m\)).
- Type
- WF4Py.WFutils.uMsun = 1.9884099021470415e+30¶
Solar mass (\({\rm M}_{\odot}\)) in kilograms (\(\rm kg\)).
- Type
- WF4Py.WFutils.clight = 299792.458¶
Speed of light in vacuum (\(c\)), in kilometers per second (\(\rm km / s\)).
- Type
- WF4Py.WFutils.clightGpc = 9.715611022447906e-18¶
Speed of light in vacuum (\(c\)), in gigaparsecs per second (\(\rm Gpc / s\)).
- Type
- WF4Py.WFutils.GMsun_over_c3 = 4.925491025543576e-06¶
Geometrized solar mass \(G \, {\rm M}_{\odot} / c^3\), in seconds (\(\rm s\)).
- Type
- WF4Py.WFutils.GMsun_over_c2 = 1476.6250614046494¶
Geometrized solar mass \(G \, {\rm M}_{\odot} / c^2\), in meters (\(\rm m\)).
- Type
- WF4Py.WFutils.GMsun_over_c2_Gpc = 4.785415917274701e-23¶
Geometrized solar mass \(G \, {\rm M}_{\odot} / c^2\), in gigaparsec (\(\rm Gpc\)).
- Type
- WF4Py.WFutils.f_isco = 2198.587345545212¶
ISCO frequency coefficient for a Schwarzschild BH, in \(\rm Hz\).
- Type
- WF4Py.WFutils.f_qK = 2585.0¶
Coefficient for the limit of the quasi-Keplerian approximation, in \(\rm Hz\), as in arXiv:2108.05861 (see also arXiv:1605.00304). This is more conservative than two times the Schwarzschild ISCO.
- Type