@article{AntonioukKiselevTarkhanov2015, author = {Antoniouk, Alexandra Viktorivna and Kiselev, Oleg M. and Tarkhanov, Nikolai Nikolaevich}, title = {Asymptotic Solutions of the Dirichlet Problem for the Heat Equation at a Characteristic Point}, series = {Ukrainian mathematical journal}, volume = {66}, journal = {Ukrainian mathematical journal}, number = {10}, publisher = {Springer}, address = {New York}, issn = {0041-5995}, doi = {10.1007/s11253-015-1038-8}, pages = {1455 -- 1474}, year = {2015}, abstract = {The Dirichlet problem for the heat equation in a bounded domain aS, a"e (n+1) is characteristic because there are boundary points at which the boundary touches a characteristic hyperplane t = c, where c is a constant. For the first time, necessary and sufficient conditions on the boundary guaranteeing that the solution is continuous up to the characteristic point were established by Petrovskii (1934) under the assumption that the Dirichlet data are continuous. The appearance of Petrovskii's paper was stimulated by the existing interest to the investigation of general boundary-value problems for parabolic equations in bounded domains. We contribute to the study of this problem by finding a formal solution of the Dirichlet problem for the heat equation in a neighborhood of a cuspidal characteristic boundary point and analyzing its asymptotic behavior.}, language = {en} } @article{BagderinaTarkhanov2015, author = {Bagderina, Yulia Yu. and Tarkhanov, Nikolai Nikolaevich}, title = {Solution of the equivalence problem for the third Painleve equation}, series = {Journal of mathematical physics}, volume = {56}, journal = {Journal of mathematical physics}, number = {1}, publisher = {American Institute of Physics}, address = {Melville}, issn = {0022-2488}, doi = {10.1063/1.4905383}, pages = {15}, year = {2015}, abstract = {We find necessary conditions for a second order ordinary differential equation to be equivalent to the Painleve III equation under a general point transformation. Their sufficiency is established by reduction to known results for the equations of the form y ' = f (x, y). We consider separately the generic case and the case of reducibility to an autonomous equation. The results are illustrated by the primary resonance equation.}, language = {en} } @article{FedchenkoTarkhanov2015, author = {Fedchenko, Dmitri and Tarkhanov, Nikolai Nikolaevich}, title = {An index formula for Toeplitz operators}, series = {Complex variables and elliptic equations}, volume = {60}, journal = {Complex variables and elliptic equations}, number = {12}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1747-6933}, doi = {10.1080/17476933.2015.1050007}, pages = {1764 -- 1787}, year = {2015}, abstract = {We prove a Fedosov index formula for the index of Toeplitz operators connected with the Hardy space of solutions to an elliptic system of first-order partial differential equations in a bounded domain in R-n with smooth boundary.}, language = {en} } @article{FedchenkoTarkhanov2015, author = {Fedchenko, Dmitry and Tarkhanov, Nikolai Nikolaevich}, title = {A Class of Toeplitz Operators in Several Variables}, series = {Advances in applied Clifford algebras}, volume = {25}, journal = {Advances in applied Clifford algebras}, number = {4}, publisher = {Springer}, address = {Basel}, issn = {0188-7009}, doi = {10.1007/s00006-015-0546-9}, pages = {811 -- 828}, year = {2015}, abstract = {We introduce the concept of Toeplitz operator associated with the Laplace-Beltrami operator on a compact Riemannian manifold with boundary. We characterise those Toeplitz operators which are Fredholm, thus initiating the index theory.}, language = {en} } @article{LyTarkhanov2015, author = {Ly, Ibrahim and Tarkhanov, Nikolai Nikolaevich}, title = {Generalized Beltrami equations}, series = {Complex variables and elliptic equations}, volume = {60}, journal = {Complex variables and elliptic equations}, number = {1}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1747-6933}, doi = {10.1080/17476933.2013.876759}, pages = {24 -- 37}, year = {2015}, abstract = {We enlarge the class of Beltrami equations by developing a stability theory for the sheaf of solutions of an overdetermined elliptic system of first-order homogeneous partial differential equations with constant coefficients in Rn.}, language = {en} }