Abstract. The problem of the stable determination of the coefficients
of second order elliptic partial differential equations arising in inverse
problems is considered. Results of uniqueness and stability at the boundary were obtained in [3] and extended in [8,9] for the conductivity equation. The common features of these papers are the employment of the singular solutions and the monotonicity assumption introduced in [3].
We revisit the techniques adopted in these papers to stably determine
the absorption coefficient in anisotropic media by means of Optical tomography (OT) in the so-called static case. This also shows that the monotonicity assumption is realistic at least in the context of OT.
