lira (version 1.0)

distance.LCDM: Angular diameter distance in a LCDM universe

Description

Angular diameter distance in a LCDM (Cold Dark Matter universe with a cosmological constant) universe between an observer at 'zd' and a source at 'zs'. The distance is in units of the Hubble distance c/H0, where 'c' is the speed of light and 'H0' is the Hubble constant.

Usage

distance.LCDM(zo=0.0,z,Omega.M0=0.3,Omega.L0=0.7)

Arguments

zo

redshift of the observer.

z

redshift of the source.

Omega.M0

present day matter density in units of the critical density.

Omega.L0

renormalized cosmological constant in units of the critical density.

Value

• The estimate of the distance.

References

Sereno M., Covone G., Piedipalumbo E., de Ritis R., (2001) Monthly Notices of the Royal Astronomical Society 327, 517-530.

See Also

See also Hubble.LCDM.

Examples

# Distance to a source at z=1 in a standard cosmology,
distance.LCDM(z=1.0) 
# Distance between a lens at zl=0.3 and a source at z=1 in an open cosmology,
distance.LCDM(0.3,1,Omega.M0=0.2,Omega.L0=0.7)