Ai. Prilepko et Ab. Kostin, ON CERTAIN INVERSE PROBLEMS FOR PARABOLIC EQUATIONS WITH FINAL AND INTEGRAL OBSERVATION, Sbornik. Mathematics, 75(2), 1993, pp. 473-490
The inverse problems of finding the free term and the coefficient of u
(x, t) in a parabolic equation is considered. The Fredholm property of
the linear inverse problem of finding the right-hand side of a specia
l form is proved, along with global existence, uniqueness, and stabili
ty theorems for its solutions. A uniqueness theorem is established for
the nonlinear inverse problem of determining the coefficient under re
strictions in the form of inequalities containing no smallness conditi
ons. The proof is carried out by a method of a priori estimates, with
the use of the maximum principle for parabolic and elliptic equations.
A connection between the uniqueness of the solution of the inverse pr
oblem and the completeness of a certain system of functions is establi
shed.