TeV gravity in four dimensions?

Abstract

We describe a model in which the fundamental scale M_\star of the theory which unifies gravity and quantum mechanics is in the TeV range, but without requiring additional spacetime dimensions. The weakness of gravity at low energies is due to a large vacuum expectation of a dilaton like field. The model requires a small dimensionless parameter (the self-coupling of the dilaton) but no fine-tuning. We discuss in detail the dynamical assumptions about nonperturbative quantum gravity required within the model. We observe that M_\star could be quite small, less than a TeV, and that the model could lead to copious strong coupling effects at the LHC. However, semiclassical black holes will not be produced.