Graduate Has a calculation of the vacuum energy density been done with strings?

[JandeWandelaar]

TL;DR

The vacuum energy density of the vacuum, as calculated in standard QFT, shows a discrepancy of about $10^{120}$ with what we see. Has the value been calculated in string theory, which doesn't assume point-like particles?

The calculation of the vacuum energy density gives us a discrepancy with reality. There should be a mass equivalent of about $10^{96}$ kilograms. I'm wondering if the assumed point-like "structure" of particles could be the cause of this wrong value.

Since string theory doesn't assume a point-like structure, I asked myself if a calculation of the energy density with strings has been done.

 

[Vanadium 50]

The calculation of the vacuum energy density gives us a discrepancy with reality.

Nonsense. There is no such calculation. At best, there is an estimate, and not a very good one at that.

Starting threads by presenting incorrect statements as facts is, in general, not a good plan.

 

[JandeWandelaar]

Why does the estimate differ so much with what we see? Is there an estimate in string theory? I could not find it. Only estimates in standard QFT.

 

[JandeWandelaar]

Nonsense. There is no such calculation. At best, there is an estimate, and not a very good one at that.

Starting threads by presenting incorrect statements as facts is, in general, not a good plan.

BTW, do you know why the LaTex doesn't function? Is $10^{120}$ not right?

 

[Delta2]

BTW, do you know why the LaTex doesn't function? Is $10^{120}$ not right?

you got to put double $ at start and end. And then refresh the page.

 

[malawi_glenn]

BTW, do you know why the LaTex doesn't function? Is $10^{120}$ not right?

for LaTeX on the forum: https://www.physicsforums.com/help/latexhelp/

This is a summary of how the $10^{120}$ discrepancy calculation is done, it is a bit heuristic
https://www.cantorsparadise.com/the...iction-in-the-history-of-physics-5be09b309043
Calculating vacuum energy in various QFTs is a thing, there are several papers published on that matter. Here is one such article https://arxiv.org/abs/1302.5934

 

[JandeWandelaar]

Thanks dude (am I allowed...?).

 

[Delta2]

Is this about the so called, ground state energy of the fields?

 

[PeterDonis]

Why does the estimate differ so much with what we see?

Nobody knows. This is an open area of research.

Is there an estimate in string theory? I could not find it.

I'm not aware of one either.

 

[JandeWandelaar]

Nobody knows. This is an open area of research.I'm not aware of one either.

Somehow I think $$10^{120}$$ and the cube of the Planck length, $$10^{-115}$$, are related.

 

[PeterDonis]

Somehow I think $$10^{120}$$ and the cube of the Planck length, $$10^{-115}$$, are related.

Personal speculation of this kind is off limits here.

 

[PeterDonis]

The OP question has been answered. Thread closed.