In cosmology (or to be more speci c, cosmography, the measurement of the Universe) there are many ways to specify the distance between two points, because in the expanding Universe, …

In standard cosmology, comoving distance and proper distance (or physical distance) are two closely related distance measures used by cosmologists to define distances between objects. …

We define a proper distance, as the distance between two events, A and B, in a reference frame for which they occur simultaneously (tA = tB). Once again, we start with the Robertson-Walker …

It forms the observational evidence from which astronomers infer the distances of most distant galaxies, by using some cosmological model to convert from redshift to distance. The look …

Distance measures are used in physical cosmology to give a natural notion of the distance between two objects or events in the universe.

Mar 13, 2021 · if we could construct a cosmological-sized ruler between the galaxy and the Earth then we would measure a quantity known as the proper distance to the galaxy. This is the …

Dec 1, 2021 · if we could construct a cosmological-sized ruler between the galaxy and the Earth then we would measure a quantity known as the proper distanceto the galaxy. The proper …

This module provides a set of routines to calculate a number of cosmological quantities based on distance and time. Some are a bit complex - e.g. the volume element at a given redshift - while …

Three distances based on observational methods are the angular diameter distance ra, proper motion distance rm, and luminosity distance rl. rl = (1 + z) rm = (1 + z)2 ra. This is closely …

All cosmological tests essentially consist of comparing some measure of (relative) distance (or look-back time) to redshift. Absolute distance scaling is given by the H0.