CosmoFit.cosmology.DistanceIntegrator

class CosmoFit.cosmology.DistanceIntegrator(cosmology, zmax=5.0, ngrid=None, interpolator='hermite')

Bases: object

Fast evaluator for the dimensionless comoving distance.

The integral

χ(z) = ∫ dz / E(z)

is computed only once on a dense redshift grid and subsequently evaluated through a monotonic PCHIP interpolation.

Parameters:

• cosmology (Cosmology) – Cosmological model.

• zmax (float, optional) – Maximum redshift of the interpolation grid.

• ngrid (int, optional) – Number of grid points. If None, an adaptive grid size is automatically selected.

• interpolator (str, optional) – Interpolation method. Currently only “hermite” is implemented.

__init__(cosmology, zmax=5.0, ngrid=None, interpolator='hermite')

Parameters:

• zmax (float)

• ngrid (int | None)

• interpolator (str)

Methods

__init__(cosmology[, zmax, ngrid, interpolator])
chi(z)	Evaluate the dimensionless comoving distance.
prepare(zmax[, ngrid])	Prepare the integration grid.
rebuild()	Recompute the chi(z) interpolation table from the current state of the associated cosmology.