TY - INPR A1 - Dyachenko, Evgueniya A1 - Tarkhanov, Nikolai Nikolaevich T1 - Degeneration of boundary layer at singular points N2 - We study the Dirichlet problem in a bounded plane domain for the heat equation with small parameter multiplying the derivative in t. The behaviour of solution at characteristic points of the boundary is of special interest. The behaviour is well understood if a characteristic line is tangent to the boundary with contact degree at least 2. We allow the boundary to not only have contact of degree less than 2 with a characteristic line but also a cuspidal singularity at a characteristic point. We construct an asymptotic solution of the problem near the characteristic point to describe how the boundary layer degenerates. T3 - Preprints des Instituts für Mathematik der Universität Potsdam - 1(2012)23 KW - Heat equation KW - Dirichlet problem KW - characteristic points KW - boundary layer Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-60135 ER - TY - INPR A1 - Antoniouk, Alexandra Viktorivna A1 - Kiselev, Oleg A1 - Stepanenko, Vitaly A1 - Tarkhanov, Nikolai Nikolaevich T1 - Asymptotic solutions of the Dirichlet problem for the heat equation at a characteristic point N2 - The Dirichlet problem for the heat equation in a bounded domain is characteristic, for there are boundary points at which the boundary touches a characteristic hyperplane t = c, c being a constant. It was I.G. Petrovskii (1934) who first found necessary and sufficient conditions on the boundary which guarantee that the solution is continuous up to the characteristic point, provided that the Dirichlet data are continuous. This paper initiated standing interest in studying general boundary value problems for parabolic equations in bounded domains. We contribute to the study by constructing a formal solution of the Dirichlet problem for the heat equation in a neighbourhood of a characteristic boundary point and showing its asymptotic character. T3 - Preprints des Instituts für Mathematik der Universität Potsdam - 1(2012)25 KW - Heat equation KW - the first boundary value problem KW - characteristic boundary point KW - cusp Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-61987 ER -