dimensionless scale factor a {\displaystyle a} . Also known as the cosmic scale factor or sometimes the Robertson–Walker scale factor, this is a key...

Scale (ratio) Scale (map) Scale factor (computer science) Scale factor (cosmology) Scales of scale models Scaling in statistical estimation Scaling in...

d_{H}(t)=R(t)\int _{0}^{t}{\frac {dt'}{R(t')}}} where R is the Scale factor (cosmology) with dimensions of length.: 36  In terms of comoving distance...

equations, R(t) is the cosmological scale factor, G {\displaystyle G} is the Newtonian constant of gravitation, Λ is the cosmological constant with dimension...

Vilenkin, Alexander (12 September 2008). "Predicting the cosmological constant with the scale-factor cutoff measure". Physical Review D. 78 (6): 063520. arXiv:0805...

in time with certain cosmological models will yield a moment when the scale factor was zero; our current understanding of cosmology sets this time at 13...

In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the very early universe...

is the correct theory of gravity on cosmological scales. It emerged in the late 1990s as a concordance cosmology, after a period when disparate observed...

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

expansion of the universe (increasing scale factor), except perhaps the dark energy term. It is the values of these cosmological parameters which physicists use...

equation of state of the cosmological constant is w = − 1 {\displaystyle w=-1} . In this case, the above expression for the scale factor is not valid and a...

A black hole cosmology (also called Schwarzschild cosmology or black hole cosmological model) is a cosmological model in which the observable universe...

time to reach the Solar System and Earth since the beginning of the cosmological expansion. Assuming the universe is isotropic, the distance to the edge...

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

cosmological principle, which holds that isotropy and homogeneity apply spatially but not temporally. The exponential expansion of the scale factor means...

Plasma cosmology is a non-standard cosmology whose central postulate is that the dynamics of ionized gases and plasmas play important, if not dominant...

distances measure on the two dimensional surface. Similarly the cosmological scale factor is not a distance in our 3 dimensional space, but its value affects...

In particle physics and physical cosmology, Planck units are a system of units of measurement defined exclusively in terms of four universal physical...

In cosmology, decoupling is a period in the development of the universe when different types of particles fall out of thermal equilibrium with each other...

Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description...

R(t) is called the scale factor of the universe, and increases as the universe expands in a manner that depends upon the cosmological model selected. Its...

In physical cosmology and astronomy, dark energy is a proposed form of energy that affects the universe on the largest scales. Its primary effect is to...

String cosmology is a relatively new field that tries to apply equations of string theory to solve the questions of early cosmology. A related area of...

In cosmology, recombination refers to the epoch during which charged electrons and protons first became bound to form electrically neutral hydrogen atoms...

The flatness problem (also known as the oldness problem) is a cosmological fine-tuning problem within the Big Bang model of the universe. Such problems...

The Cosmology Large Angular Scale Surveyor (CLASS) is an array of microwave telescopes which has been observing since 2016 from a high-altitude site in...

physical cosmology, cosmological perturbation theory is the theory by which the evolution of structure is understood in the Big Bang model. Cosmological perturbation...

He then examines the conditions for the appearance of life on cosmological time scales. Assuming the rate of evolution of life on Earth and considering...

Cosmogony Cosmology Timeline of cosmological theories Timeline of knowledge about galaxies, clusters of galaxies, and large-scale structure Large-scale structure...

In physical cosmology, the age of the universe is the time elapsed since the Big Bang: 13.79 billion years. Astronomers have two different approaches...