On Emission Tomography of Inhomogeneous Media

The problem of finding the source distribution for particles (or radiation) in a bounded domain D from the emitting flow through the boundary of D is considered. The particles are supposed to move with unit velocity along geodesics of a Riemannian metric and can be absorbed by the medium. The metric and the absorption are known. Uniqueness of the solution to this problem and a stability estimate are obtained under a certain assumption on the absorption and curvature of the metric.