G. Alessandrini et al., LOCAL UNIQUENESS IN THE INVERSE CONDUCTIVITY PROBLEM WITH ONE MEASUREMENT, Transactions of the American Mathematical Society, 347(8), 1995, pp. 3031-3041
We prove local uniqueness of a domain D entering the conductivity equa
tion div((1 + chi(D))del u) = 0 in a bounded planar domain Omega given
the Cauchy data for u on a part of partial derivative Omega. The main
assumption is that del u has zero index on partial derivative Omega w
hich is easy to guarantee by choosing special boundary data for u. To
achieve our goals we study index of critical points of u on partial de
rivative Omega.