Inherent identifiability of parameters in elliptic differential equations (Q1120758)

Consider an inverse problem for the second order linear elliptic equation \(-div(a \text{grad} u)=f,\) where f is given and a is to be determined. This paper deals with the question of the uniqueness and continuous dependence of a in terms of u without a priori assumptions on the sign of \(| \nabla u|\). This question is called to be of inherent identifiability of parameters in distributed systems.