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Plasma cosmology is a non-standard cosmology whose central postulate is that the dynamics of ionized gases and plasmas play important, if not dominant, roles in the physics of the universe beyond the Solar System.〔It was described as this in the February 1992 issue of ''Sky & Telescope'' ("Plasma Cosmology"), and by Anthony Peratt in the 1980s, who describes it as a "nonstandard picture". The ΛCDM model big bang picture is typically described as the "concordance model", "standard model" or "standard paradigm" of cosmology (here ), and (here ).〕〔Alfven, Hannes O. G., "Cosmology in the plasma universe - an introductory exposition", ''IEEE Transactions on Plasma Science'' (ISSN 0093-3813), vol. 18, Feb. 1990, p. 5-10.〕 This is contrary to the general consensus by cosmologists and astrophysicists which strongly supports that astronomical bodies and structures in the universe are mostly influenced by gravity, Einstein's theory of general relativity, and quantum mechanics. These can be used to explain the origin, structure and evolution of the universe on cosmic scales. , the vast majority of researchers openly reject plasma cosmology because it does not match modern observations of astrophysical phenomena or accepted cosmological theory. Some general concepts about plasma cosmology originated with Hannes Alfvén, who won the 1970 Nobel Prize in Physics for his other (unrelated) work in magnetohydrodynamics (MHD).〔His MHD research found that magnetic fields can induce currents in a moving conductive fluid, which in turn creates forces on the fluid and also changes the magnetic field itself.〕〔Helge S. Kragh, ''Cosmology and Controversy: The Historical Development of Two Theories of the Universe'', 1996 Princeton University Press, 488 pages, ISBN 0-691-00546-X ((pp.482-483 ))〕 Alfvén proposed the use of plasma scaling to extrapolate the results of laboratory experiments and space plasma physics observations and scale them over many orders-of-magnitude up to the largest observable objects in the universe (see box〔). The term plasma universe is sometimes used as a synonym for plasma cosmology, as an alternative description of the plasma in the universe.〔 ==Alfvén-Klein cosmology== In the 1960s, the theory behind plasma cosmology was introduced by Alfvén, Oskar Klein and Carl-Gunne Fälthammar, and Alfvén's 1966 book ''Worlds-Antiworlds''. Klein in 1971 extended Alfvén's ''Worlds-Antiworlds'' proposals and developed the "Alfvén-Klein model" of the universe, or metagalaxy, an earlier term to distinguish between the universe and the Milky Way galaxy. In this Alfvén-Klein cosmology, sometimes called Klein-Alfvén cosmology, the universe is made up of equal amounts of matter and antimatter with the boundaries between the regions of matter and antimatter being delineated by cosmic electromagnetic fields formed by double layers, thin regions comprising two parallel layers with opposite electrical charge. Interaction between these boundary regions would generate radiation, and this would form the plasma. Alfvén introduced the term ambiplasma for a plasma made up of matter and antimatter and the double layers are thus formed of ambiplasma. According to Alfvén, such an ambiplasma would be relatively long-lived as the component particles and antiparticles would be too hot and too low-density to annihilate each other rapidly. The double layers will act to repel clouds of opposite type, but combine clouds of the same type, creating ever-larger regions of matter and antimatter. The idea of ambiplasma was developed further into the forms of heavy ambiplasma (protons-antiprotons) and light ambiplasma (electrons-positrons).〔 Alfvén-Klein cosmology was proposed in part to explain the observed baryon asymmetry in the universe, starting from an initial condition of exact symmetry between matter and antimatter. According to Alfvén and Klein, ambiplasma would naturally form pockets of matter and pockets of antimatter that would expand outwards as annihilation between matter and antimatter occurred in the double layer at the boundaries. They concluded that we must just happen to live in one of the pockets that was mostly baryons rather than antibaryons, explaining the baryon asymmetry. The pockets, or bubbles, of matter or antimatter would expand because of annihilations at the boundaries, which Alfvén considered as a possible explanation for the observed expansion of the universe, which would be merely a local phase of a much larger history. Alfvén postulated that the universe has always existed〔: "issues now a hundred years old were debated including plasma cosmology's traditional refusal to claim any knowledge about an 'origin' of the universe (e.g., Alfvén, 1988)"〕 due to causality arguments and the rejection of ''ex nihilo'' models, such as the Big Bang, as a stealth form of creationism.〔Alfvén, Hannes, ("Cosmology: Myth or Science?" ) (1992) ''IEEE Transactions on Plasma Science'' (ISSN 0093-3813), vol. 20, no. 6, p. 590-600〕 The exploding double layer was also suggested by Alfvén as a possible mechanism for the generation of cosmic rays,〔Hannes Alfvén, ''Cosmic plasma''. Taylor & Francis US, 1981,IV.10.3.2, p.109. "Double layers may also produce extremely high energies. This is known to take place in solar flares, where they generate solar cosmic rays up to 109 to 1010 eV."〕 x-ray bursts and gamma-ray bursts.〔Alfvén, H., ("Double layers and circuits in astrophysics" ), (1986) ''IEEE Transactions on Plasma Science'' (ISSN 0093-3813), vol. PS-14, Dec. 1986, p. 779-793. Based on the NASA sponsored conference "(Double Layers in Astrophysics )" (1986)〕 In 1993, theoretical cosmologist Jim Peebles criticized Alfvén-Klein cosmology, writing that "there is no way that the results can be consistent with the isotropy of the cosmic microwave background radiation and X-ray backgrounds".〔P. J. E. Peebles, (''Principles of Physical Cosmology'' ), (1993) Princeton University Press, p. 207, ISBN 978-0-691-07428-3〕 In his book he also showed that Alfvén's models do not predict Hubble's law, the abundance of light elements, or the existence of the cosmic microwave background. A further difficulty with the ambiplasma model is that matter–antimatter annihilation results in the production of high energy photons, which are not observed in the amounts predicted. While it is possible that the local "matter-dominated" cell is simply larger than the observable universe, this proposition does not lend itself to observational tests. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Plasma cosmology」の詳細全文を読む スポンサード リンク
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