TY - JOUR A1 - Alsaedy, Ammar A1 - Tarkhanov, Nikolai Nikolaevich T1 - Normally solvable nonlinear boundary value problems JF - Nonlinear analysis : theory, methods & applications ; an international multidisciplinary journal N2 - We investigate nonlinear problems which appear as Euler-Lagrange equations for a variational problem. They include in particular variational boundary value problems for nonlinear elliptic equations studied by F. Browder in the 1960s. We establish a solvability criterion of such problems and elaborate an efficient orthogonal projection method for constructing approximate solutions. KW - Nonlinear Laplace operator KW - Boundary value problem KW - Dirichlet to Neumann operator Y1 - 2014 U6 - https://doi.org/10.1016/j.na.2013.09.024 SN - 0362-546X SN - 1873-5215 VL - 95 SP - 468 EP - 482 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Tarkhanov, Nikolai Nikolaevich T1 - The dirichlet to Neumann operator for elliptic complexes JF - Transactions of the American Mathematical Society N2 - We define the Dirichlet to Neumann operator for an elliptic complex of first order differential operators on a compact Riemannian manifold with boundary. Under reasonable conditions the Betti numbers of the complex prove to be completely determined by the Dirichlet to Neumann operator on the boundary. KW - Elliptic complexes KW - Dirichlet to Neumann operator KW - inverse problems Y1 - 2011 SN - 0002-9947 VL - 363 IS - 12 SP - 6421 EP - 6437 PB - American Mathematical Soc. CY - Providence ER - TY - INPR A1 - Alsaedy, Ammar A1 - Tarkhanov, Nikolai Nikolaevich T1 - Normally solvable nonlinear boundary value problems N2 - We study a boundary value problem for an overdetermined elliptic system of nonlinear first order differential equations with linear boundary operators. Such a problem is solvable for a small set of data, and so we pass to its variational formulation which consists in minimising the discrepancy. The Euler-Lagrange equations for the variational problem are far-reaching analogues of the classical Laplace equation. Within the framework of Euler-Lagrange equations we specify an operator on the boundary whose zero set consists precisely of those boundary data for which the initial problem is solvable. The construction of such operator has much in common with that of the familiar Dirichlet to Neumann operator. In the case of linear problems we establish complete results. T3 - Preprints des Instituts für Mathematik der Universität Potsdam - 2(2013)11 KW - Nonlinear Laplace operator KW - boundary value problem KW - Dirichlet to Neumann operator Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-65077 SN - 2193-6943 ER -