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Feb14-12, 08:36 AM
P: 381
Quote Quote by atyy View Post
In perturbative string theory, massless spin 2 = spacetime curvature (deviation from flat spacetime) emerges as an excitation of the string. So this is the same idea as gravitons producing spacetime curvature. However, gravitons are not fundamental since they are just one excitation type of the string, and the string is more fundamental.

In AdS/CFT, even strings are not fundamental, and instead emerge holographically from the boundary theory.

Earlier when I mentioned about the idea of flat spacetime + gravitons = curve spacetime. Marcus emphasized it was not standard in string theory. Now you are saying it's standard. Or maybe if we add strings in the context. Then it's standard in string theory. When no strings and just the idea of flat spacetime + gravitons = curve spacetime , then not standard. Is this it? Please elaborate as this got me confused for 5 years already. Thanks.