Depletion potential near curved surfaces.

We examine the depletion potential and force of a hard-sphere fluid on a single big hard sphere, located inside or outside of a hard spherical cavity, by Monte Carlo simulations to the hard-sphere fluid. The depletion potential is determined by the acceptance ratio method, while the force on the big sphere is obtained by two methods: numerical differentiation of the depletion potential and integration of the contact density of the fluid at the surface of the big sphere. The results are in excellent agreement with those obtained by density functional theory presented by Roth et al.