• 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 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
  • 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 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
  • 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 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 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...
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  • 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...
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  • 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 De Sitter universe
    cosmological principle, which holds that isotropy and homogeneity apply spatially but not temporally. The exponential expansion of the scale factor means...
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  • 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 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 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 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
  • Thumbnail for Chronology of the universe
    describes the history and future of the universe according to Big Bang cosmology. Research published in 2015 estimates the earliest stages of the universe's...
    111 KB (10,671 words) - 19:09, 13 May 2025
  • 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
  • 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...
    143 KB (16,931 words) - 12:43, 14 May 2025
  • Thumbnail for Cosmic distance ladder
    this scale visible, but has been measured with percent-level precision (see baryon acoustic oscillations). The scale does depend on cosmological parameters...
    56 KB (8,092 words) - 18:42, 9 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 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 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) - 16:41, 16 May 2025
  • Thumbnail for Cosmological constant problem
    the Planck energy cutoff and other factors, the quantum vacuum energy contribution to the effective cosmological constant is calculated to be between...
    21 KB (2,464 words) - 23:39, 16 March 2025
  • Thumbnail for Big Bang
    Big Bang (redirect from Big Bang cosmology)
    relativity has passed stringent tests on the scale of the Solar System and binary stars. The cosmological principle has been confirmed to a level of 10−5...
    150 KB (15,947 words) - 21:47, 7 May 2025
  • Thumbnail for Age of the universe
    Age of the universe (category Physical cosmological concepts)
    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...
    32 KB (3,882 words) - 16:21, 5 May 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