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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 .
In physics, quintessence is a hypothetical form of dark energy, more precisely a scalar field minimally coupled to gravity, postulated as an explanation of the observation of an accelerating rate of expansion of the universe. The first example of this scenario was proposed by Ratra and Peebles (1988) [1] and Wetterich (1988).
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.
The cosmological constant was originally introduced in Einstein's 1917 paper entitled “The cosmological considerations in the General Theory of Reality”. [2] Einstein included the cosmological constant as a term in his field equations for general relativity because he was dissatisfied that otherwise his equations did not allow for a static universe: gravity would cause a universe that was ...
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} .
Robert R. Caldwell is an American theoretical physicist and professor of physics and astronomy at Dartmouth College. His research interests include cosmology and gravitation. [2] He is known primarily for his work on theories of cosmic acceleration, [3] in particular dark energy, quintessence, [4] and the Big Rip scenario. [5] [6]
Energy teleportation sounds like the stuff of science fiction, but now, research shows that you CAN actually pull energy from nothing. Scientists Defy Physics, Basically Pull Energy Out of Thin ...
In this scenario, the equation of state = of the dark energy, relating its pressure and energy density, can cross the boundary = associated with the cosmological constant. The boundary separates the phantom-energy-like behavior with w < − 1 {\displaystyle w<-1} from the quintessence-like behavior with w > − 1 {\displaystyle w>-1} .