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| double | a | Read / Write / Construct Only |
| double | critical-delta | Read / Write / Construct Only |
| double | p | Read / Write / Construct Only |
Object implementation to compute the halo bias function given the Sheth-Tormen mass function for spherical collapse. A description of the function is given below. Check nc_halo_bias.c for a description of halo biases and nc_multiplicity_func_st.c for the Sheth-Tormen mass function.
The Sheth-Tormen bias can be obtained in the same way as the Press-Schechter bias by performing a perturbative expansion in the mass function around the background density contrast. This bias has a significant impact on less massive halos, and for a spherical collapse is given by \begin{align} b(\nu)=1+\frac{a \nu^2-1}{\delta_c}+\frac{2 p}{\delta_c\left[1+\left(a_c \nu^2\right)^p\right]} \end{align} where $b(\nu)$ is the bias, $\delta_c$ is the critical threshold, $\nu = \frac{\delta_c}{\sigma}$, and $(a, p)$ are free parameters determined by the number of massive halos in the simulations and by the shape of the mass function at the low-mass end, respectively.
The user must provide input the values: NcHaloMassFunction
, delta_c
, a
, p
- nc_halo_bias_st_spher_new_full().
NcHaloBiasSTSpher *
nc_halo_bias_st_spher_new (NcHaloMassFunction *mfp);
Creates a new NcHaloBiasSTSpher object with undefined parameters.
[constructor]
NcHaloBiasSTSpher * nc_halo_bias_st_spher_new_full (NcHaloMassFunction *mfp,gdouble delta_c,gdouble a,gdouble p);
Creates a new NcHaloBiasSTSpher object with the input values.
void nc_halo_bias_st_spher_set_delta_c (NcHaloBiasSTSpher *biasf_st_spher,gdouble delta_c);
Sets the value delta_c
to the “critical-delta” property.
gdouble
nc_halo_bias_st_spher_get_delta_c (const NcHaloBiasSTSpher *biasf_st_spher);
void nc_halo_bias_st_spher_set_a (NcHaloBiasSTSpher *biasf_st_spher,gdouble a);
Sets the value a
to the “a” property.
gdouble
nc_halo_bias_st_spher_get_a (const NcHaloBiasSTSpher *biasf_st_spher);
void nc_halo_bias_st_spher_set_p (NcHaloBiasSTSpher *biasf_st_spher,gdouble p);
Sets the value p
to the “p” property.
gdouble
nc_halo_bias_st_spher_get_p (const NcHaloBiasSTSpher *biasf_st_spher);
“a” property “a” double
Bias parameter determined by the number of massive halos in the simulations. (check limits values)
Owner: NcHaloBiasSTSpher
Flags: Read / Write / Construct Only
Allowed values: >= 0
Default value: 0.75
“critical-delta” property “critical-delta” double
Critical delta.
Owner: NcHaloBiasSTSpher
Flags: Read / Write / Construct Only
Allowed values: >= 0
Default value: 1.686