Cosmological Constant and the like

[blumfeld0]

I have a few questions that have been piling up.

1.
Einstein introduced the cosmoligical constant to demand a static universe like so, G + (Lambda * metric tensor) = T
If you were to calculate the perihelion precession of mercury, bending of starlight etc. with this additional term would you get the same results or would you get significantly different numbers in the end?
I suspect they would be different but hardly noticeable in the final numbers but I am not sure. Has anyone tried to do this? If so, what does it mean for the cosmological constant lamba.


2. Is dark energy the physial manifestation of the cosmological constant? Is dark energy the same as the higgs field (not the electroweak or grand unified higgs field, responsible for giving particles mass) but the higgs field responsible for Inflation in the early universe?
I thought the answer to the first question was yes but the consensus seems to change every month

Lastly,
3. What implications does dark energy have on the overall curvature and fate of the universe? Doesnt it throw everything we know into panic mode? We know the vast majority of the universe is composed of dark energy so what implications does that have?



blumfeld0

 

[SpaceTiger]

Perhaps you've seen it already, but if not, check out my brief review of dark energy https://www.physicsforums.com/showpost.php?p=893482&postcount=82".

If you were to calculate the perihelion precession of mercury, bending of starlight etc. with this additional term would you get the same results or would you get significantly different numbers in the end?
I suspect they would be different but hardly noticeable in the final numbers but I am not sure.

You're correct. There's some detailed discussion of the impact of dark energy on orbits in this thread:

https://www.physicsforums.com/showthread.php?t=103450"

2. Is dark energy the physial manifestation of the cosmological constant?

In the simplest model, yes. However, there are many reasonable theories in which the dark energy density is not a constant (w != -1). These are generally referred to as "quintessence" models.

Is dark energy the same as the higgs field (not the electroweak or grand unified higgs field, responsible for giving particles mass) but the higgs field responsible for Inflation in the early universe?

No, it most probably isn't related to the scalar field that caused inflation.

3. What implications does dark energy have on the overall curvature and fate of the universe? Doesnt it throw everything we know into panic mode? We know the vast majority of the universe is composed of dark energy so what implications does that have?

The end fate of the universe is something we can only speculate about because there is always the possibility some other "dark" component will become dominant in the far future. If the current cosmological model is the whole picture (unlikely), then the universe will suffer a heat death, just as in the open universe model. Lots more information here:

http://math.ucr.edu/home/baez/end.html"