Gershtein L. M.
Ukr. Mat. Zh. - 1993. - 45, № 10. - pp. 1449–1454
For the complete second-order differential equation with unbounded operator coefficients $u'' + A(t)u' + B(i)u = f, \quad u(0) = u_o, \quad u'(0)=u_1$ the Cauchy problem is studied. By using the "coinmutant method", we construct the coercive solution of this problem is in the Holder space in the case where the operator $В$ has the same "strength" as the operator $А^2$.
Ukr. Mat. Zh. - 1993. - 45, № 8. - pp. 1162–1165
The study of a model system of differential equations arising from the dynamical problems of thermo elasticity is continued. The case of shifts of the general type is investigated. We employ the “commutant method” based on the properties of the operator $\Delta(A, B) = AB - BA$.
Ukr. Mat. Zh. - 1989. - 41, № 7. - pp. 898-905