@article{LyTarkhanov2020, author = {Ly, Ibrahim and Tarkhanov, Nikolaj Nikolaevič}, title = {Asymptotic expansions at nonsymmetric cuspidal points}, series = {Mathematical notes}, volume = {108}, journal = {Mathematical notes}, number = {1-2}, publisher = {Springer Science}, address = {New York}, issn = {0001-4346}, doi = {10.1134/S0001434620070238}, pages = {219 -- 228}, year = {2020}, abstract = {We study the asymptotics of solutions to the Dirichlet problem in a domain X subset of R3 whose boundary contains a singular point O. In a small neighborhood of this point, the domain has the form {z > root x(2) + y(4)}, i.e., the origin is a nonsymmetric conical point at the boundary. So far, the behavior of solutions to elliptic boundary-value problems has not been studied sufficiently in the case of nonsymmetric singular points. This problem was posed by V.A. Kondrat'ev in 2000. We establish a complete asymptotic expansion of solutions near the singular point.}, language = {en} } @unpublished{DyachenkoTarkhanov2012, author = {Dyachenko, Evgueniya and Tarkhanov, Nikolai Nikolaevich}, title = {Degeneration of boundary layer at singular points}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60135}, year = {2012}, abstract = {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.}, language = {en} }