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Phantom energy is a hypothetical form of dark energy satisfying the equation of state = with <. It possesses negative kinetic energy , and predicts expansion of the universe in excess of that predicted by a cosmological constant , which leads to a Big Rip .
The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. [1] The concept of an expanding universe was scientifically originated by physicist Alexander Friedmann in 1922 with the mathematical derivation of the Friedmann equations.
Hypothetical phantom energy would have an equation of state <, and would cause a Big Rip. Using the existing data, it is still impossible to distinguish between phantom w < − 1 {\displaystyle w<-1} and non-phantom w ≥ − 1 {\displaystyle w\geq -1} .
Some special cases of quintessence are phantom energy, in which the energy density of quintessence actually increases with time, and k-essence (short for kinetic quintessence) which has a non-standard form of kinetic energy such as a negative kinetic energy. [53] They can have unusual properties: phantom energy, for example, can cause a Big Rip.
This phantom energy density would become infinite in finite time, causing such a huge gravitational repulsion that the universe would lose all structure and end in a Big Rip. [26] For example, for w = − 3 / 2 and H 0 =70 km·s −1 ·Mpc −1, the time remaining before the universe ends in this Big Rip is 22 billion years. [27]
The theory he devised to explain what he found is called the Big Bang theory. [citation needed] In 1931, Lemaître proposed in his "hypothèse de l'atome primitif" (hypothesis of the primeval atom) that the universe began with the "explosion" of the "primeval atom" – what was later called the Big Bang.
If the theory of inflation is correct, the universe went through an episode dominated by a different form of dark energy in the first moments of the Big Bang; but inflation ended, indicating an equation of state much more complicated than those assumed so far for present-day dark energy. It is possible that the dark energy equation of state ...
Phase transitions can be categorised by their order.Transitions which are first order proceed via bubble nucleation and release latent heat as the bubbles expand.. As the universe cooled after the hot Big Bang, such a phase transition would have released huge amounts of energy, both as heat and as the kinetic energy of growing bubbles.