new physics. Moreover, one has the facility of polarizing the beams, which can play a significant role in background elimination. It is also possible to run such a machine in the $e^- e^-$, $e\gamma$ and $\gamma\gamma$ modes. In this paper we consider the possibility of using a high energy $e^+ e^-$ collider to detect signatures of low-scale quantum gravity in a model with large extra dimensions. In particular, we focus on Bhabha scattering with radiated gravitons.

One of the most exciting theoretical developments of recent years has been the idea that there could be one or more extra spatial dimensions and the observable Universe could be confined to a four-dimensional hypersurface in a higher-dimensional ‘bulk’ spacetime[@Akama]. Such ideas, which can be motivated by superstring theories, give rise to elegant solutions[@ADD] to the well-known gauge hierarchy problem of high energy physics, which is just the instability against quantum corrections mentioned above. What is even more interesting, perhaps, is the suggestion[@GRW; @HLZ] that there could be observable signals of quantum gravity at current and future accelerator experiments, and this possibility has spawned a vast and increasing body of work over the past five years. This relatively new set of ideas, commonly dubbed 