- #316
arivero
Gold Member
- 3,493
- 167
Adrian, if you have read the GSW you will be already suspecting that they do not get the SM gauge groups straight from the big ones, but they go to special shapes in compactification, all that brane stuff. The book of Ibañez is better source for this way that the GSW tomes. Perhaps you have here a good intuition that going to D-brane intersection and special configurations is the way to avoid the need of discovering too many generators, and associated fermions. They can make the case that only the zero modes, the massless particles in the high dimensional representation, have some sense in the low energy, and then they can even purge them via the configuration.