Gravity modifications from extra dimensions

Lowering the string scale in the TeV region provides a theoretical framework for solving the mass hierarchy problem and unifying all interactions. The apparent weakness of gravity can then be accounted for by the existence of large internal dimensions, in the submillimetre region, and transverse to a braneworld where our universe must be confined. I review the main properties of this scenario and its implications for observations at both particle colliders, and in non-accelerator gravity experiments. Such effects are for instance the production of Kaluza–Klein resonances, graviton emission in the bulk of extra dimensions, and a radical change of gravitational forces in the submillimetre range. I also discuss localization of gravity in the presence of infinite size extra dimensions that can modify Newton's law at cosmological distance scales.