Redshift vs. Time:

= - *H*_{0}(1 + *z*)^{2}(*z* + 1)^{1/2}

where *z* is the redshift, *t* the cosmic time, *H*_{0} is Hubble's
constant, and
the current density of the universe, in
units of

Angular Size:

=

where
is the angle subtended on Earth by an object
of proper length *d* at redshift *z*. *D* is given by the expression

Flux:

where *S* is the energy received per second per square metre on earth, and
*L* is the luminosity emitted by the object at redshift *z* in a second
(object frame).