with_H0

astropy.cosmology.units.with_H0(H0=None)[source]

Convert between quantities with little-h and the equivalent physical units.

Parameters:
H0python:None or Quantity [:ref: ‘frequency’]

The value of the Hubble constant to assume. If a Quantity, will assume the quantity is H0. If None (default), use the H0 attribute from default_cosmology.

References

For an illuminating discussion on why you may or may not want to use little-h at all, see https://arxiv.org/pdf/1308.4150.pdf