Big rip
In physical cosmology, the Big Rip is a hypothetical cosmological model concerning the ultimate fate of the universe, in which the matter of the universe, from stars and galaxies to atoms and subatomic particles, and even spacetime itself, is progressively torn apart by the expansion of the universe at a certain time in the future. According to the hypothesis, first published in 2003, the scale factor of the universe and with it all distances in the universe will become infinite at a time in the future. The possibility of sudden singularities and crunch or rip singularities at late times occur only for hypothetical matter with implausible physical properties.
The hypothesis relies crucially on the type of dark energy in the universe. The key value is the equation of state parameter , the ratio between the dark energy pressure and its energy density. If < −1, this dynamical vacuum energy is known as phantom energy, an extreme form of quintessence.
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