### Redshift-magnitude Relation

**(Magnitude-redshift relation)**
(how apparent magnitude depends on redshift)

The **Redshift-Magnitude Relation**
(or **Magnitude-redshift Relation**)
is a function of Redshift (or distance) that yields (effectively)
the Distance Modulus associated with that redshift: the difference
between Apparent Magnitude and Absolute Magnitude. This was
of great interest when the expansion of the universe was first being
proposed.

It is also of current interest: like the Redshift-angular Size Relation,
it is straight-forward given some simplifying approximations: in
this case, constant. However, at Cosmological distances, various
models as well as observation reveal it is not so simple, and
observation can be used to select and tweak models.

(*astrophysics,cosmology,measure*)
http://en.wikipedia.org/wiki/Redshift

https://ned.ipac.caltech.edu/level5/Sept01/Sandage/Sand4.html

https://arxiv.org/abs/1410.2469

index