String Theory and Supersymmetry

[atyy]

Cargese lectures on string theory with eight supercharges
Monica Guica, Andrew Strominger
http://arxiv.org/abs/0704.3295

The authors state "Ultimately the most interesting and most physically relevant case is no supersymmetry at all. But at the moment analytic control in this case is quite limited."

Does this mean that string theory could work without supersymmetry? How about AdS/CFT?

 

[BenTheMan]

String theory needs susy at the Planck scale. Low scale SUSY is just a nice way to keep scalars light.

Put another way, non-observation of SUSY at LHC could not rule out string theory.

 

[atyy]

String theory needs susy at the Planck scale. Low scale SUSY is just a nice way to keep scalars light.

Put another way, non-observation of SUSY at LHC could not rule out string theory.

Is there an energy above which if we don't find supersymmetry, then string theory will be falsified? ie. Is string theory falsifiable at least in principle?

 

[BenTheMan]

The Planck scale.

 

[atyy]

So if I did lots of experiments at 10^29 eV and didn't find supersymmetry, string theory would be false?

 

[BenTheMan]

Yes. If you were able to do experiments at that energy, string theory (as far as I know) would definitely be falsifiable.