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String Theory Demystified

String Theory Demystified

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CHAPTER 7 RNS Superstrings 143<br />

If we choose the R sector, then following the open string case<br />

On the other hand, if we choose the NS sector, then<br />

r = 0, ± 1, ± 2,…<br />

(7.34)<br />

1 3<br />

r =± , ± , (7.35)<br />

2 2<br />

We can choose either sector for left and right movers independently. If the<br />

sectors match for left and right movers, we obtain space-time bosons. If the<br />

sectors are different for left and right movers, then we obtain space-time fermions.<br />

That is,<br />

• Choosing the NS sector for left movers and the NS sector for right movers<br />

gives space-time bosons.<br />

• Choosing the R sector for left movers and the R sector for right movers<br />

gives space-time bosons.<br />

• Choosing the NS sector for left movers and the R sector for right movers<br />

gives space-time fermions.<br />

• Choosing the R sector for left movers and the NS sector for right movers<br />

gives space-time fermions.<br />

Super-Virasoro Generators<br />

When we quantize the theory we will need super-Virasoro operators. These are<br />

generalizations of what we have already worked out for bosonic string theory. We<br />

extend the idea in this case to include a fermionic operator. That is,<br />

B<br />

L → L + L<br />

( ) ( F )<br />

m m m<br />

It can be shown that the following defi nition will work:<br />

∞<br />

1<br />

1<br />

L = r m b b<br />

m ∑α ⋅ α + −<br />

m−n n ∑(<br />

2 ) (7.36)<br />

− r m+ r<br />

2<br />

4<br />

n=−∞<br />

r

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