A new approximate mathematical model for global convergence for a   coefficient inverse problem with backscattering data
  An approximately globally convergent numerical method for a 3d Coefficient Inverse Problem for a hyperbolic equation with backscattering data is presented. A new approximate mathematical model is presented. An approximation is used only on the first iteration and amounts to the truncation of a certain asymptotic series. A significantly new element of the convergence analysis is that the so-called "tail functions" are estimated. Numerical results in 2d and 3d cases are presented, including the one for a quite heterogeneous medium. 
Larisa Beilina and Michael V. Klibanov
math-ph math.MP