halomod.bias.ST99

class halomod.bias.ST99(nu: numpy.ndarray, delta_c: float = 1.686, m: Optional[numpy.ndarray] = None, mstar: Optional[float] = None, delta_halo: Optional[float] = 200, n: Optional[float] = 1, sigma_8: Optional[float] = 0.8, cosmo: astropy.cosmology.core.FLRW = FlatLambdaCDM(name="Planck15", H0=67.7 km / (Mpc s), Om0=0.307, Tcmb0=2.725 K, Neff=3.05, m_nu=[0.   0.   0.06] eV, Ob0=0.0486), n_eff: Optional[numpy.ndarray] = None, z: float = 0.0, **model_parameters)[source]

Peak-background split bias corresponding to ST99 HMF.

See documentation for Bias for information on input parameters. This model has no free parameters.

Notes

This bias form can be explicitly derived by assuming a Sheth-Tormen form for the HMF, as shown for example in [1]. The form is

\[1 + \frac{q\nu - 1}{\delta_c} + \frac{2p}{\delta_c ( 1 + q^p \nu^p)}\]

with p and q having default values of (0.707, 0.3). They are free in this implementation for the user to modify.

Parameters

  • p (float, optional) – The free parameters of the form.

  • q (float, optional) – The free parameters of the form.

References

1

Sheth, R. K.. and Tormen, G., “Large-scale bias and the peak background split”, https://ui.adsabs.harvard.edu/abs/1999MNRAS.308..119S, 1999

Methods

__init__(nu[, delta_c, m, mstar, …])

Initialize self.

bias()

Calculate the first-order, linear, deterministic halo bias.

get_models()

Get a dictionary of all implemented models for this component.

Attributes

pair_hmf

The HMF model that pairs with this bias in the peak-background split