• dimensionless scale factor a {\displaystyle a} . Also known as the cosmic scale factor or sometimes the Robertson–Walker scale factor, this is a key...
    13 KB (1,897 words) - 23:41, 2 April 2025
  • Scale (ratio) Scale (map) Scale factor (computer science) Scale factor (cosmology) Scales of scale models Scaling in statistical estimation Scaling in...
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  • 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...
    11 KB (1,570 words) - 03:07, 6 April 2025
  • Thumbnail for Friedmann equations
    equations, R(t) is the cosmological scale factor, G {\displaystyle G} is the Newtonian constant of gravitation, Λ is the cosmological constant with dimension...
    30 KB (4,441 words) - 23:24, 12 May 2025
  • Vilenkin, Alexander (12 September 2008). "Predicting the cosmological constant with the scale-factor cutoff measure". Physical Review D. 78 (6): 063520. arXiv:0805...
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  • Thumbnail for Expansion of the universe
    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...
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  • Thumbnail for Cosmic inflation
    In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the very early universe...
    106 KB (12,602 words) - 12:33, 4 April 2025
  • Thumbnail for Accelerating expansion of the universe
    Accelerating expansion of the universe (category Physical cosmological concepts)
    expansion of the universe (increasing scale factor), except perhaps the dark energy term. It is the values of these cosmological parameters which physicists use...
    42 KB (5,167 words) - 06:09, 7 April 2025
  • Thumbnail for Comoving and proper distances
    In standard cosmology, comoving distance and proper distance (or physical distance) are two closely related distance measures used by cosmologists to...
    18 KB (2,437 words) - 08:05, 22 April 2025
  • Thumbnail for Lambda-CDM model
    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...
    93 KB (10,918 words) - 09:54, 14 May 2025
  • Thumbnail for Equation of state (cosmology)
    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...
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  • Thumbnail for Black hole cosmology
    A black hole cosmology (also called Schwarzschild cosmology or black hole cosmological model) is a cosmological model in which the observable universe...
    7 KB (794 words) - 20:48, 11 May 2025
  • Thumbnail for Distance measure
    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...
    18 KB (2,563 words) - 06:56, 15 May 2025
  • Thumbnail for 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...
    64 KB (6,610 words) - 02:30, 13 May 2025
  • Thumbnail for Plasma cosmology
    Plasma cosmology is a non-standard cosmology whose central postulate is that the dynamics of ionized gases and plasmas play important, if not dominant...
    34 KB (3,556 words) - 20:30, 12 May 2025
  • Thumbnail for De Sitter universe
    cosmological principle, which holds that isotropy and homogeneity apply spatially but not temporally. The exponential expansion of the scale factor means...
    6 KB (762 words) - 15:50, 16 June 2024
  • Thumbnail for Friedmann–Lemaître–Robertson–Walker metric
    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...
    26 KB (3,625 words) - 09:48, 14 May 2025
  • Thumbnail for Planck units
    Planck units (redirect from Planck scale)
    In particle physics and physical cosmology, Planck units are a system of units of measurement defined exclusively in terms of four universal physical...
    54 KB (6,119 words) - 13:51, 15 May 2025
  • Thumbnail for Decoupling (cosmology)
    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...
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  • Thumbnail for Physical cosmology
    Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description...
    77 KB (7,679 words) - 05:28, 2 April 2025
  • 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...
    10 KB (1,533 words) - 08:03, 13 April 2025
  • 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...
    144 KB (16,930 words) - 01:42, 23 May 2025
  • Thumbnail for Recombination (cosmology)
    In cosmology, recombination refers to the epoch during which charged electrons and protons first became bound to form electrically neutral hydrogen atoms...
    20 KB (2,744 words) - 15:33, 18 March 2025
  • Thumbnail for Hubble's law
    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...
    132 KB (13,177 words) - 17:21, 2 May 2025
  • physical cosmology, cosmological perturbation theory is the theory by which the evolution of structure is understood in the Big Bang model. Cosmological perturbation...
    15 KB (2,050 words) - 13:23, 28 October 2023
  • Thumbnail for Dark energy
    Dark energy (category Physical cosmological concepts)
    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...
    88 KB (9,941 words) - 07:29, 18 May 2025
  • Thumbnail for Flatness problem
    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...
    33 KB (4,327 words) - 15:49, 3 November 2024
  • Thumbnail for Cosmology Large Angular Scale Surveyor
    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...
    23 KB (2,592 words) - 20:47, 17 May 2025
  • Thumbnail for Cosmology
    Cosmology (from Ancient Greek κόσμος (cosmos) 'the universe, the world' and λογία (logia) 'study of') is a branch of physics and metaphysics dealing with...
    52 KB (3,319 words) - 20:58, 22 May 2025
  • Thumbnail for Big Rip
    Big Rip (category Physical cosmology)
    to the standard model of cosmology, the scale factor of the universe is accelerating, and, in the future era of cosmological constant dominance, will...
    11 KB (1,349 words) - 13:26, 6 May 2025