Inphysical cosmology,theinflationary epochwas the period in the evolution of the earlyuniversewhen, according toinflation theory,the universe underwent an extremely rapid exponentialexpansion.This rapid expansion increased the linear dimensions of the early universe by a factor of at least 1026(and possibly a much larger factor), and so increased its volume by a factor of at least 1078.Expansion by a factor of 1026is equivalent to expanding an object 1nanometer(10−9m,about half the width of amoleculeofDNA) in length to one approximately 10.6light years(about 62 trillion miles).
Description
editVacuum state is a configuration of quantum fields representing a local minimum (but not necessarily a global minimum) of energy.
Inflationary models propose that at approximately 10−36seconds after theBig Bang,vacuum state of the Universe was different from the one seen at the present time: the inflationary vacuum had a much higher energy density.
According togeneral relativity,any vacuum state with non-zero energy density generates a repulsive force that leads to an expansion of space. In inflationary models, early high-energy vacuum state causes a very rapid expansion. This expansion explains various properties of the current universe that are difficult to account for without such an inflationary epoch.
Most inflationary models propose ascalar fieldcalled theinflatonfield, with properties necessary for having (at least) two vacuum states.
It is not known exactly when the inflationary epoch ended, but it is thought to have been between 10−33and 10−32seconds after the Big Bang. The rapid expansion of space meant that any potential elementary particles (or other "unwanted" artifacts, such as topological defects) remaining from the time before inflation were now distributed very thinly across the universe.
When the inflaton field reconfigured itself into the low-energy vacuum state we currently observe, the huge difference in potential energy was released in the form of a dense, hot mixture ofquarks, anti-quarks and gluonsas it entered theelectroweak epoch.
See also
edit- Inflation (cosmology)– Theory of rapid universe expansion
- Big Bang– Physical theory
- Chronology of the universe– History and future of the universe
Notes
editReferences
edit- Guth, Alan H.(1998).The Inflationary Universe: Quest for a New Theory of Cosmic Origins.Vintage.ISBN978-0-09-995950-2.
- Greene, Brian(2005).The Fabric of the Cosmos: Space, Time and the Texture of Reality.Penguin Books Ltd.Bibcode:2004fcst.book.....G.ISBN978-0-14-101111-0.