In the present paper, the existence and uniqueness of the strong
solution of
a mixed problem for a second order plurihyperbolic equation with an integral
condition is proved. The proof is essentially based on an a priori bound and
on the density of the range of the operator generated by the considered
problem. In spite of the apparant simplicity of the problem, the solution
requires a delicate set of techniques. It seems very difficult to extend
these technics to the considered equation in more than one dimension without
imposing complementary conditions.
Keywords: Strong solution, a priori bound, plurihyperbolic equation.