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In astronomy, dark matter is an invisible and hypothetical form of matter that does not interact with light or other electromagnetic radiation.Dark matter is implied by gravitational effects which cannot be explained by general relativity unless more matter is present than can be observed.
The Lambda-CDM, Lambda cold dark matter, or ΛCDM model is a mathematical model of the Big Bang theory with three major components: a cosmological constant , denoted by lambda (Λ), associated with dark energy ;
In cosmology and physics, cold dark matter (CDM) is a hypothetical type of dark matter.According to the current standard model of cosmology, Lambda-CDM model, approximately 27% of the universe is dark matter and 68% is dark energy, with only a small fraction being the ordinary baryonic matter that composes stars, planets, and living organisms.
Dark matter is called ‘dark’ because it’s invisible to us and does not measurably interact with anything other than gravity. It could be interspersed between the atoms that make up the Earth ...
Weakly interacting massive particles (WIMPs) are hypothetical particles that are one of the proposed candidates for dark matter.. There exists no formal definition of a WIMP, but broadly, it is an elementary particle which interacts via gravity and any other force (or forces) which is as weak as or weaker than the weak nuclear force, but also non-vanishing in strength.
Theoretically, in order to explain relatively small-scale structures in the observable Universe, it is necessary to invoke cold dark matter or WDM. In other words, hot dark matter being the sole substance in explaining cosmic galaxy formation is no longer viable, placing hot dark matter under the larger umbrella of mixed dark matter (MDM) theory.
Option (1) leads to the dark matter hypothesis; option (2) leads to MOND. The majority of astronomers, astrophysicists, and cosmologists accept dark matter as the explanation for galactic rotation curves (based on general relativity, and hence Newtonian mechanics), and are committed to a dark matter solution of the missing-mass problem. [19]
The density of dark matter in an expanding universe decreases more quickly than dark energy, and eventually the dark energy dominates. Specifically, when the volume of the universe doubles, the density of dark matter is halved, but the density of dark energy is nearly unchanged (it is exactly constant in the case of a cosmological constant).