# Susy transforrnations & gso projection

1. Sep 26, 2011

### lkwarren01

I'm a little confused about the relaionship between susy transformations involving Q generators & gso projection in superstring theory. If gso projection is used in RNS sectors, does that only eliminate certain states, such as tachyon, then susy must still be applied?

Or does gso projection inherently provide supersymmetry, so that no additional transformation is required?

Finally, if both must be used together, which goes first?

Thanks
Larry Warren

2. Sep 27, 2011

### suprised

Inherently. What is usually called "the" GSO projection is a projection that happens to produce a SUSY spectrum. Many other projections are possible and most are not supersymmetric. This nomenclature dates back to the old days and is perhaps somewhat confusing indeed.

3. Sep 27, 2011

### lkwarren01

Does that mean if GSO projection is used, no other SUSY transformation is needed?

4. Sep 27, 2011

### suprised

I am not sure what you mean with "other SUSY transformation"....certainly you can do Susy transformations, if the theory has been GSO projected in a suitable manner, and it is invariant under such transformations.

5. Sep 27, 2011

thank you