mycosmo.cosmology module

Cosmology.

This module implements various cosmology routines.

mycosmo.cosmology.critical_density(redshift, cosmo_dict)[source]

Critical Density.

Calculate the critical density at a given redshift using the cosmological parameter values provided. kjdfn,dnslkj;fn;snlnksf

Parameters:

  • redshift (float or numpy.ndarray) – Redshift(s) at which the critical density should be calculated

  • cosmo_dict (dict) –

    Dictionary of cosmological constants. Must contain the following keys:

    • H0: The Hubble parameter value at redshift zero.

    • omega_m_0: The matter density at redshift zero.

    • omega_k_0: The curvature density at redshift zero.

    • omega_lambda_0: The dark energy density at redshift zero.

Returns:

Value of the critical density (km/m^3) at the specified redshift(s) for a given cosmology.

Return type:

float or numpy.ndarray

Notes

This function implements the calculation of the critical density as follows:

\[\rho_c(z) = \frac{3H^2(z)}{8\pi G}\]

Examples

>>> from mycosmo.cosmology import critical_density
>>> cosmo_dict = {"H0": 70, "omega_m_0": 0.3, "omega_k_0": 0.0, "omega_lambda_0": 0.7}
>>> critical_density(0.0, cosmo_dict)
9.203859495267889e-27
mycosmo.cosmology.hubble(redshift, cosmo_dict)[source]

Hubble Parameter.

Calculate the Hubble parameter at a given redshift using the cosmological parameter values provided.

Parameters:

  • redshift (float or numpy.ndarray) – Redshift(s) at which the Hubble parameter should be calculated

  • cosmo_dict (dict) –

    Dictionary of cosmological constants. Must contain the following keys:

    • H0: The Hubble parameter value at redshift zero.

    • omega_m_0: The matter density at redshift zero.

    • omega_k_0: The curvature density at redshift zero.

    • omega_lambda_0: The dark energy density at redshift zero.

Returns:

Value of the Hubble parameter (km/s/Mpc) at the specified redshift(s) for a given cosmology.

Return type:

float or numpy.ndarray

Notes

This function implements the calculation of the Hubble parameter as follows:

\[H(z) = \sqrt{H_0^2 (\Omega_{m,0}(1+z)^3 + \Omega_{k,0}(1+z)^2 + \Omega_{\Lambda,0})}\]

Examples

>>> from mycosmo.cosmology import hubble
>>> cosmo_dict = {"H0": 70, "omega_m_0": 0.3, "omega_k_0": 0.0, "omega_lambda_0": 0.7}
>>> hubble(0.0, cosmo_dict)
70.0