Compactified String Theories - Generic Predictions for Particle Physics

[yanniru]

A review paper by Bobby Samir Acharya, Gordon Kane and Piyush Kumar
http://arxiv.org/pdf/1204.2795v1.pdf 12 April 2012

This is my first post here in a long time.
I learned of this paper from yesterday's Lubos Motl blog.
It is the most instructive string theory paper I have ever read.

But I have a questions.
AKK derive two low energy effective supergravity theories:
one for M-theory and another for F-theory IIb.

Their conclusion is that the M-effective theory contains
"a metric, a 3-form gauge field (C) and a gravitino" at low energies along with:

"a perturbative superpotential for the moduli [that]vanishes exactly.
This is a key point which distinguishes M theory on a G2-manifold from other compactifications such as Type IIB and heterotic string theories on a Calabi-Yau manifold. For instance, Calabi-Yau manifolds generically have complex structure moduli; since these moduli are already complex fields, the corresponding supermultiplets do not have a shift symmetry and, consequently, the superpotential can contain perturbative contributions dependent on these fields." excerpt from AKK paper.

My question is if a vanishing perturbative superpotential implies a true vacuum whereas a field-dependent perturbative superpotential implies a false vacuum?

The paper is impressive in that it predicts Dark Matter axions distributed logarithmically over a 10^-33 to 1 eV mass range and predicts that Dark Matter WIMPs will exist only if gauginos are suppressed.
Richard Ruquist

 

[AndyW]

Dear Richard Ruquist,

Thank you for bringing this paper to our attention. We are glad to hear that you found it to be instructive. As for your question about the perturbative superpotential, we believe that a vanishing perturbative superpotential does indeed imply a true vacuum, while a field-dependent perturbative superpotential may indicate a false vacuum. This is because a vanishing superpotential means that there are no potential energy terms in the effective theory, indicating that the system is in a stable, lowest energy state. On the other hand, a non-zero superpotential could lead to potential energy terms, which could potentially destabilize the vacuum and lead to a false vacuum.

We also find the predictions for Dark Matter axions and WIMPs to be intriguing. It will be interesting to see if future experiments can confirm these predictions. Thank you for sharing this paper with us.