Hi,(adsbygoogle = window.adsbygoogle || []).push({});

I've got a (confusing) question about string theory.

Analyzing the massless modes of the closed string gives me three fields, which correspond to the fact that reps of the group SO(D) (or SO(D-1,1) ) can be breaken apart into three irreps:

*A symmetric traceless part

*An antisymmetric part

* A trace part

The first is our graviton. But, for instance, in General relativity the metric is not traceless with respect to the Minkowski metric! So what's going on?

I know that in a lightcone analysis of the linearized Einstein equations in D dimensions you can show that the physical degrees of freedom are in the traceless symmetric (D-2)x(D-2) part of the metric. Does this have to do with my question? Or am I mixing up things now?

Thanks in advance! :)

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# Traceless metric in string spectrum

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