Quintessence (physics)

In physics, quintessence postulates a hypothetical form of dark energy, which is blamed for an increasing expansion of the universe. There is so far no evidence of quintessence, and there are a variety under this term aggregated theories with some similarities.

Bottom line is for theoretical ideas a scalar field whose equation of state w has a value which is less than -1 / 3. This w is the ratio of pressure p to density ρ w = p / ρ. In contrast to the cosmological constant, w = -1, the quintessence of the world changes over time.

Many models include quintessence, have a follow-up scheme whereby the problem of the cosmological constant is partially solved. In these models, the quintessence field has a density following the radiation density (but still slightly lower ) by a balance between radiation and matter occurs. From this point on quintessential acts as dark energy, which determines to view the evolution of the universe.

Some special cases of quintessence are " phantom energy " with w < -1 and K- essence ( Kinetic essence) with a non-standard form of kinetic energy.

The term bottom line comes from the Pythagoreans, according to which the four classical elements of a fifth, just the bottom line (from Latin quinta essentia, " fifth beings " ), also known as ether, had emerged. In this sense, one can also appeal to the Higgs field of the current standard model of elementary particle physics as the quintessence, as it is uniformly present throughout the universe and gives many elementary particles ( apart from things like the Higgs boson itself) its mass.