[Author] Senik N. N. [Title] Homogenization for the Periodic Elliptic Second Order Differential Operator in a Strip with Various Boundary Conditions [AMS Subj-class] 35B27 Homogenization; partial differential equations in media with periodic structure [Abstract] The paper concerns homogenization for the elliptic operator in $ L_2(\Pi) $, $ \Pi=\R \times (0, a) $, defined by the differential expression $ B_{\lambda}^{\epsilon} = \sum_{j = 1}^{2} D_j g_j(x_1 / \epsilon, x_2) D_j + \sum_{j = 1}^{2} (h_j(x_1 / \epsilon, x_2) D_j + D_j h_j^*(x_1 / \epsilon, x_2)) + Q(x_1 / \epsilon, x_2\) + \lambda Q_*(x_1 / \epsilon, x_2) $ with periodic, Neumann or Dirichlet boundary conditions. All the coefficients are assumed to be periodic of period 1 with respect to the first variable. Sharp-order approximations for the inverse of $ B_{\lambda}^{\epsilon} $ in the operator norms (from $ L_2 (\Pi) $ to $ L_2 (\Pi) $) and (from $ L_2 (\Pi) $ to $ H^1 (\Pi) $) are obtained, with error terms being $ O(\epsilon) $. [Keywords] homogenization, operator error estimates, periodic differential operators, effective operator, corrector [Comments] Russian, 52 pp. [Contact e-mail] N.N.Senik@gmail.com