Capabilities include

cosmolopy.density

Various cosmological densities.

cosmolopy.distance

Various cosmological distance measures.

cosmolopy.luminosityfunction

Galaxy luminosity functions (Schecter functions).

cosmolopy.magnitudes

Conversion in and out of the AB magnitude system.

cosmolopy.parameters

Pre-defined sets of cosmological parameters (e.g. from WMAP).

cosmolopy.perturbation

Perturbation theory and the power spectrum.

cosmolopy.reionization

The reionization of the IGM.

Functions take cosmological parameters (which can be numpy arrays) as keywords, and ignore any extra keywords. This means you can make a dictionary of all of your cosmological parameters and pass it to any function.

The parameters module supplies some convenient pre-defined parameter sets.

Usage

The easiest way to use CosmoloPy is to create a dictionary of the cosmology parameters and pass it to each function using the ** syntax.

>>> import cosmolopy.distance as cd
>>> cosmo = {'omega_M_0':0.3, 'omega_lambda_0':0.7, 'omega_k_0':0.0, 'h':0.72}
>>> d_co = cd.comoving_distance(6., **cosmo)
>>> print "Comoving distance to z=6 is %.1f Mpc" % (d_co)
Comoving distance to z=6 is 8017.8 Mpc

The cosmolopy package also defines some convenient shortcuts, including a fiducial cosmology (currently the WMAP7+BAO+H0 mean), so you can just do this:

>>> from cosmolopy import *
>>> d_a = cd.angular_diameter_distance(6, **fidcosmo)
>>> print "Angluar-diameter distance to z=6 is %.1f Mpc" % (d_a)
Angluar-diameter distance to z=6 is 1209.9 Mpc
>>> d_light = cd.light_travel_distance(6, **fidcosmo)
>>> print "Light-travel distance to z=6 is %.1f Mpc" % (d_light)
Light-travel distance to z=6 is 3922.9 Mpc

Calculate the mass of a halo with Virial temperature of 10^4 kelvin, then verify the Virial temperature for a halo of that mass:

>>> import cosmolopy.perturbation as cp
>>> cosmo = {'omega_M_0' : 0.27,
... 'omega_lambda_0' : 1-0.27,
... 'omega_b_0' : 0.045,
... 'omega_n_0' : 0.0,
... 'N_nu' : 0,
... 'h' : 0.72,
... 'n' : 1.0,
... 'sigma_8' : 0.9
... }
>>> mass = cp.virial_mass(1e4, 6.0, **cosmo)
>>> temp = cp.virial_temp(mass, 6.0, **cosmo)
>>> print "Mass = %.3g M_sun" % mass
Mass = 1.68e+08 M_sun
>>> print round(temp, 4)
10000.0

Calculate the critical and matter densities:

>>> from cosmolopy import *
>>> 'rho_crit=%.3g Msun/Mpc^3, rho_0=%.3g Msun/Mpc^3' % cden.cosmo_densities(**fidcosmo)
'rho_crit=1.38e+11 Msun/Mpc^3, rho_0=3.75e+10 Msun/Mpc^3'

Look in the tests/ and examples/ directories for more examples.