Bobyk I. O.
Ukr. Mat. Zh. - 1994. - 46, № 7. - pp. 795–802
By using a metric approach, we study the problem of well-posedness of boundary-value problems for hyperbolic equations of ordern (n?2) with constant coefficients in a cylindrical domain. Conditions of existence and uniqueness of solutions are formulated in number-theoretic terms. We prove a metric theorem on lower estimates of small denominators that appear when constructing solutions.