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  2. Dark energy - Wikipedia

    en.wikipedia.org/wiki/Dark_energy

    Since it is rarefied and un-massive—roughly 10 −27 kg/m 3 —it is unlikely to be detectable in laboratory experiments. The reason dark energy can have such a profound effect on the universe, making up 68% of universal density in spite of being so dilute, is that it is believed to uniformly fill otherwise empty space.

  3. Cosmological constant - Wikipedia

    en.wikipedia.org/wiki/Cosmological_constant

    [6] [7] [8] The cosmological constant Λ is the simplest possible explanation for dark energy, and is used in the standard model of cosmology known as the ΛCDM model. According to quantum field theory (QFT), which underlies modern particle physics, empty space is defined by the vacuum state, which is composed of a collection of quantum fields.

  4. Lambda-CDM model - Wikipedia

    en.wikipedia.org/wiki/Lambda-CDM_model

    The fraction of the total energy density of our (flat or almost flat) universe that is dark energy, , is estimated to be 0.669 ± 0.038 based on the 2018 Dark Energy Survey results using Type Ia supernovae [7] or 0.6847 ± 0.0073 based on the 2018 release of Planck satellite data, or more than 68.3% (2018 estimate) of the mass–energy density ...

  5. Zero-point energy - Wikipedia

    en.wikipedia.org/wiki/Zero-point_energy

    This would indicate empty space exerted some form of negative pressure or energy. There is no natural candidate for what might cause what has been called dark energy but the current best guess is that it is the zero-point energy of the vacuum, but this guess is known to be off by 120 orders of magnitude. [138]

  6. Cosmological constant problem - Wikipedia

    en.wikipedia.org/wiki/Cosmological_constant_problem

    Depending on the Planck energy cutoff and other factors, the quantum vacuum energy contribution to the effective cosmological constant is calculated to be between 50 and as many as 120 orders of magnitude greater than has actually been observed, [1] [2] a state of affairs described by physicists as "the largest discrepancy between theory and ...

  7. Void (astronomy) - Wikipedia

    en.wikipedia.org/wiki/Void_(astronomy)

    Instead of the general notion that a void is a region of space with a low cosmic mean density; a hole in the distribution of galaxies, it defines voids to be regions in which matter is escaping; which corresponds to the dark energy equation of state, w.

  8. Vacuum energy - Wikipedia

    en.wikipedia.org/wiki/Vacuum_energy

    Using the upper limit of the cosmological constant, the vacuum energy of free space has been estimated to be 10 −9 joules (10 −2 ergs), or ~5 GeV per cubic meter. [3] However, in quantum electrodynamics , consistency with the principle of Lorentz covariance and with the magnitude of the Planck constant suggests a much larger value of 10 113 ...

  9. Inhomogeneous cosmology - Wikipedia

    en.wikipedia.org/wiki/Inhomogeneous_cosmology

    An inhomogeneous cosmology is a physical cosmological theory (an astronomical model of the physical universe's origin and evolution) which, unlike the dominant cosmological concordance model, assumes that inhomogeneities in the distribution of matter across the universe affect local gravitational forces (i.e., at the galactic level) enough to skew our view of the Universe. [3]