A generalized variant of the Calder\'on problem from electrical impedance
tomography with partial data for anisotropic Lipschitz conductivities is
considered in an arbitrary space dimension nā„2. The following two
results are shown: (i) The selfadjoint Dirichlet operator associated with an
elliptic differential expression on a bounded Lipschitz domain is determined
uniquely up to unitary equivalence by the knowledge of the Dirichlet-to-Neumann
map on an open subset of the boundary, and (ii) the Dirichlet operator can be
reconstructed from the residuals of the Dirichlet-to-Neumann map on this
subset.Comment: to appear in Comm. Partial Differential Equation