nbodykit.cosmology.power.zeldovich module¶

class nbodykit.cosmology.power.zeldovich.ZeldovichJ0(k)[source]¶

Bases: mcfit.mcfit.mcfit

An integral over \(j_0\) needed to compute the Zeldovich power. The integral is given by:

\[I_0(r) = \int \frac{dk}{2\pi^2} P_L(k) j_0(kr).\]

Methods

`__call__`(F[, extrap])
`check`(F)	rough sanity checks on the input

class nbodykit.cosmology.power.zeldovich.ZeldovichJ1(k)[source]¶

Bases: mcfit.mcfit.mcfit

An integral over \(j_1\) needed to compute the Zeldovich power. The integral is given by:

\[I_1(r) = \int \frac{dk}{2\pi^2} P_L(k) \frac{j_1(kr)}{kr}.\]

Methods

`__call__`(F[, extrap])
`check`(F)	rough sanity checks on the input

class nbodykit.cosmology.power.zeldovich.ZeldovichPower(cosmo, redshift, transfer='CLASS')[source]¶

The matter power spectrum in the Zel’dovich approximation.

Parameters:	cosmo (`Cosmology`) – the cosmology instance z (float) – the redshift of the power spectrum transfer (str, optional) – string specifying the transfer function to use for the linear power spectrum; one of ‘CLASS’, ‘EisensteinHu’, ‘NoWiggleEisensteinHu’

cosmo¶: class:Cosmology, astropy.cosmology.FLRW – the object giving the cosmological parameters

Plin¶: class:LinearPower – the linear power spectrum class used to compute the Zel’dovich power

Attributes

`attrs`	The meta-data dictionary
`redshift`	The redshift of the power spectrum
`sigma8`	The amplitude of matter fluctuations at \(z=0\).

Methods

__call__(k) Return the Zel’dovich power in \(h^{-3} \mathrm{Mpc}^3 at :attr:`redshift\) and k, where k is in units of \(h \mathrm{Mpc}^{-1}\).

__call__(k)[source]¶

Return the Zel’dovich power in \(h^{-3} \mathrm{Mpc}^3 at :attr:`redshift\) and k, where k is in units of \(h \mathrm{Mpc}^{-1}\).

Parameters:	k (float, array_like) – the wavenumbers to evaluate the power at

class nbodykit.cosmology.power.zeldovich.ZeldovichPowerIntegral(r, n)[source]¶

Bases: mcfit.mcfit.mcfit

The integral needed to evaluate the density auto spectrum in the Zel’dovich approximation.

This evaluates:

\[I(k, n) = 4\pi \int dr r^2 \mathrm{exp}\left[-0.5k^2(X(r) + Y(r)) \right] \left (\frac{k Y(r)}{r} \right)^n j_n(kr).\]

Methods

`__call__`(F[, extrap])
`check`(F)	rough sanity checks on the input

nbodykit.cosmology.power.zeldovich.isiterable(obj)[source]¶: Returns True if the given object is iterable.

nbodykit.cosmology.power.zeldovich.vectorize_if_needed(func, *x)[source]¶: Helper function to vectorize functions on array inputs