- #1
stglyde
- 275
- 0
How come a "positive-energy false vacuum would, according to general relativity, generate an exponential expansion of space"?
If we have a smoothly-distributed energy density, then the expansion of space (neglecting spatial curvature) can be written as:stglyde said:How come a "positive-energy false vacuum would, according to general relativity, generate an exponential expansion of space"?
The concept of inflation in the expansion of spacetime refers to the rapid and exponential growth of the universe in the first few moments after the Big Bang. It is believed to have occurred due to a sudden and dramatic increase in the energy density of the universe, causing it to expand at an incredibly fast rate.
The theory of inflation suggests that during the rapid expansion of the universe, any tiny fluctuations or irregularities in the distribution of matter and energy were stretched out and smoothed over, resulting in a more uniform universe. This is known as the "horizon problem" and is one of the main pieces of evidence for the inflation theory.
Dark energy is a hypothetical form of energy that is thought to be responsible for the accelerating expansion of the universe. It is believed to make up about 70% of the total energy in the universe and its presence is necessary to explain the observed expansion of spacetime.
The expansion of spacetime does not affect the motion of galaxies within a local cluster. However, on a larger scale, the expansion causes the space between galaxy clusters to stretch, resulting in a gradual increase in the distance between them. This is known as the "Hubble flow".
One of the key pieces of evidence for the expansion of spacetime is the redshift of light from distant galaxies. This redshift is interpreted as the result of galaxies moving away from us, and the magnitude of the redshift increases with distance, indicating that the expansion is occurring on a large scale. Additionally, observations of the cosmic microwave background radiation also support the theory of expansion and inflation.