james.goetz said:I am examining various models of eternal inflation and I want to double check one of my assumptions, which is that space always expands when the space has vacuum energy and zero mass. Is this correct? Will space always expand when the space has vacuum energy and zero mass? Thank you.
This is not correct. The vacuum energy during inflation was positive. Are you mistakenly referring to the negative pressure of the vacuum?Mark M said:James, space will expand when there is a negative vacuum energy, such as there was during inflation.
Also, I think this statement is a little confusing, since you seem to be implying that it is a result of the negative pressure that the field finds its way to the true vacuum. This is also not the case -- it is simply that the true vacuum is of lower energy than the false vacuum, and the inflaton, through quantum/thermal fluctuations, tends to find its way down to the true vacuum....while in a false vacuum, exerted a negative pressure to decay to a true vacuum
bapowell said:This is not correct. The vacuum energy during inflation was positive. Are you mistakenly referring to the negative pressure of the vacuum?
James, a vacuum energy-dominated universe will expand always.
EDIT:...while in a false vacuum, exerted a negative pressure to decay to a true vacuum
Also, I think this statement is a little confusing, since you seem to be implying that it is a result of the negative pressure that the field finds its way to the true vacuum. This is also not the case -- it is simply that the true vacuum is of lower energy than the false vacuum, and the inflaton, through quantum/thermal fluctuations, tends to find its way down to the true vacuum.
bapowell said:This is not correct. The vacuum energy during inflation was positive. Are you mistakenly referring to the negative pressure of the vacuum?
Also, I think this statement is a little confusing, since you seem to be implying that it is a result of the negative pressure that the field finds its way to the true vacuum. This is also not the case -- it is simply that the true vacuum is of lower energy than the false vacuum, and the inflaton, through quantum/thermal fluctuations, tends to find its way down to the true vacuum.
He was speaking to me, I used the word 'to' which implies the decay was a direct cause of the negative pressure. And as bapowell said, the negative pressure is related to the inflaton field being in the false vacuum, and decayed because of standard processes.james.goetz said:By the way, I never said "...while in a false vacuum, exerted a negative pressure to decay to a true vacuum."
The current understanding of cosmology suggests that the expansion of space will continue indefinitely. This is due to the presence of vacuum energy and the fact that the universe appears to be flat, meaning there is no curvature to slow down the expansion.
Vacuum energy is a theoretical form of energy that is thought to permeate all of space. It has a constant density and is responsible for the accelerating expansion of the universe. It is believed to counteract the gravitational forces that would otherwise cause the universe to collapse.
The expansion of space does not directly affect objects within it, as it operates on a larger scale. However, the expansion does cause the distances between objects to increase over time. This effect is more noticeable over vast distances, such as between galaxies.
According to current theories, the expansion of space is uniform on large scales. This means that the rate of expansion is the same in all directions and at all points in space. However, on smaller scales, such as within galaxy clusters, the expansion may be affected by local gravitational forces.
There is currently no evidence to suggest that the expansion of space can create new matter. The expansion of space simply causes the distances between existing matter to increase. However, some theories suggest that the energy of the vacuum could potentially create new particles, but this has not been observed or proven.