Infinite volume radius extrapolation for two body bound states in finite volume

Simulations of quantum systems in finite volume have proven to be a useful aid in calculating physical observables. Most notably finite volume effects on the energy of a variety of systems have already been investigated in great depth. The aim of this project is to derive finite volume relations for the radius of a system analogous to those that exist for the energy. We report the volume dependence of the mean square radius for two body bound states. We verify this result by demonstrating a robust method for extracting the infinite volume radius from finite volume simulation data in a cubic box with periodic boundary conditions.