Well, it does, but it gets the magnitude completely wrong (off by a factor of 10^120).paweld said:How QFT might possibly explain existence of cosmological constant.
Does it predict that vacuum stress energy tensor has on it's diagonal
positive time component (density of energy) and negative spatial
components (preasure=-density)?
If the vacuum has a constant energy density, one that is independent of space and time, then it is a cosmological constant.paweld said:Let's forget for a moment about this factor. I'm interested in more general problem.
Is true at least that vacuum stress energy tensor
has on it's diagonal positive time component (density of energy) and negative spatial
components (preasure=-density), so that it could play similar role as cosmological
constant?
ThanksChalnoth said:If the vacuum has a constant energy density, on that is independent of space and time, then it is a cosmological constant.
The cosmological constant is a term originally introduced by Albert Einstein in his theory of general relativity to represent a constant energy density that fills the entire universe.
In quantum field theory, the cosmological constant is considered as the vacuum energy density, which is the lowest possible energy state of a quantum field. This concept is used to explain the observed acceleration of the expansion of the universe.
In modern physics, the cosmological constant is considered to be a fundamental constant of nature. It is believed to be responsible for the observed acceleration of the universe's expansion and plays a crucial role in our understanding of the structure and evolution of the universe.
The existence of the cosmological constant has a significant impact on the universe. It is believed to be the driving force behind the expansion of the universe and is responsible for the observed dark energy, which makes up about 70% of the total energy in the universe.
According to current theories, the cosmological constant is a constant value that does not change over time. However, some theories suggest that it may vary on extremely long timescales or in different regions of the universe. This is still an area of active research and is not yet fully understood.