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Why does the observable universe have more matter than antimatter? (more unsolved problems in physics) In physical cosmology , leptogenesis is the generic term for hypothetical physical processes that produced an asymmetry between leptons and antileptons in the very early universe , resulting in the present-day dominance of leptons over ...
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).
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.
In physical cosmology, the baryon asymmetry problem, also known as the matter asymmetry problem or the matter–antimatter asymmetry problem, [1] [2] is the observed imbalance in baryonic matter (the type of matter experienced in everyday life) and antibaryonic matter in the observable universe.
"Our understanding of the universe contains a lot of ignorance about two elements - dark matter and dark energy - and these make up 96% of the universe, so this is no small matter."
The Big Bang should have produced equal amounts of matter and antimatter if CP-symmetry was preserved; as such, there should have been total cancellation of both—protons should have cancelled with antiprotons, electrons with positrons, neutrons with antineutrons, and so on. This would have resulted in a sea of radiation in the universe with ...
The epoch of recombination occurred during a matter dominated era of the universe, so we can approximate () as () (+). Putting these together, we see that the angular diameter distance, or the size of the observable universe for a redshift z r e c ≈ 1100 {\displaystyle z_{rec}\approx 1100} is
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.