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Neither the standard model of particle physics nor the theory of general relativity provides a known explanation for why this should be so, and it is a natural assumption that the universe is neutral with all conserved charges. [3] The Big Bang should have produced equal amounts of matter and antimatter. Since this does not seem to have been ...
The local geometry of the universe is determined by whether the relative density Ω is less than, equal to or greater than 1. From top to bottom: a spherical universe with greater than critical density (Ω>1, k>0); a hyperbolic, underdense universe (Ω<1, k<0); and a flat universe with exactly the critical density (Ω=1, k=0). The spacetime of ...
In physical cosmology, baryogenesis (also known as baryosynthesis [1] [2]) is the physical process that is hypothesized to have taken place during the early universe to produce baryonic asymmetry, the observation that only matter and not antimatter (antibaryons) is detected in universe other than in cosmic ray collisions.
All the particles that make up the matter around us, such electrons and protons, have antimatter versions which are nearly identical, but with mirrored properties such as the opposite electric charge.
Another question for astroparticle physicists is why is there so much more matter than antimatter in the universe today. Baryogenesis is the term for the hypothetical processes that produced the unequal numbers of baryons and antibaryons in the early universe, which is why the universe is made of matter today, and not antimatter. [6]
In November 2010, the ALPHA collaboration announced that they had trapped 38 antihydrogen atoms for a sixth of a second, [23] the first confinement of neutral antimatter. In June 2011, they trapped 309 antihydrogen atoms, up to 3 simultaneously, for up to 1,000 seconds. [24] They then studied its hyperfine structure, gravity effects, and charge.
The universe's expansion rate, a figure called the Hubble constant, is measured in kilometers per second per megaparsec, a distance equal to 3.26 million light-years.
A vacuum is defined as a space with as little energy in it as possible. Despite the name, the vacuum still has quantum fields.A true vacuum is stable because it is at a global minimum of energy, and is commonly assumed to coincide with the physical vacuum state we live in.