Quintom scenario
Encyclopedia
Quintom scenario is a hypothetical scenario of dark energy
with the equation of state
crossing the cosmological constant boundary (
) from above to below, or oppositely. Theoretically, a No-Go theorem has been proved showing that, to generate this scenario, at least two degrees of freedom are required for dark energy models.
If this scenario exists, it may indicate how the universe avoids the dooms of time-like singularities, such as Big Bang
, Big Rip
, and so on. For example, one application of quintom scenario in 2008 was to a model of inflationary cosmology without big bang
singularity.
One application of quintom in 2007 was in a big bounce
model of the universe.
Dark energy
In physical cosmology, astronomy and celestial mechanics, dark energy is a hypothetical form of energy that permeates all of space and tends to accelerate the expansion of the universe. Dark energy is the most accepted theory to explain recent observations that the universe appears to be expanding...
with the equation of state
Equation of state (cosmology)
In cosmology, the equation of state of a perfect fluid is characterized by a dimensionless number \! w, equal to the ratio of its pressure \! p to its energy density \! \rho: \! w=p/\rho...
crossing the cosmological constant boundary (
) from above to below, or oppositely. Theoretically, a No-Go theorem has been proved showing that, to generate this scenario, at least two degrees of freedom are required for dark energy models.If this scenario exists, it may indicate how the universe avoids the dooms of time-like singularities, such as Big Bang
Big Bang
The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
, Big Rip
Big Rip
The Big Rip is a cosmological hypothesis first published in 2003, about the ultimate fate of the universe, in which the matter of the universe, from stars and galaxies to atoms and subatomic particles, is progressively torn apart by the expansion of the universe at a certain time in the future...
, and so on. For example, one application of quintom scenario in 2008 was to a model of inflationary cosmology without big bang
Big Bang
The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
singularity.
One application of quintom in 2007 was in a big bounce
Big Bounce
The Big Bounce is a theoretical scientific model of the formation of the known universe. It is implied by the cyclic model or oscillatory universe interpretation of the Big Bang where the first cosmological event was the result of the collapse of a previous universe.- Expansion and contraction...
model of the universe.
External links
- Dark Energy Constraints from the Cosmic Age and Supernova by Bo Feng, Xiulian Wang and Xinmin Zhang
- Crossing the Phantom Divide by Martin Kunz and Domenico Sapone
- A Model Of Inflationary Cosmology Without Singularity by Yi-Fu Cai, Taotao Qiu, Jun-Qing Xia and Xinmin Zhang
- Quintom Cosmology: theoretical implications and observations by Yi-Fu Cai, Emmanuel N. Saridakis, Mohammad R. Setare and Jun-Qing Xia