Joint research work with A. Bouchnita. Mathematical models and computer programs for describing the coagulation of blood in the stream considering biochemical reactions in the plasma and aggregation of platelets were developed. The terms of normal clot growth and thrombosis were obtained. Two articles are in print this year.

Necessary and sufficient terms for the boundedness of fractional maximal operators in general Morrie local spaces are for a wide class of admissible values of numerical parameters were obtained together with A. Gogatishvili. Sufficient and necessary terms for this kind of limitation for a certain range of parameters were obtained.

The terms that ensure the boundedness of Hausdorff operators in Morrie spaces were obtained together with E. Liflyand. The classes of Hausdorff operators for which the necessary and sufficient terms of boundedness coincide were described.

The problem of the limitation of various operators (Riesz potential, the maximum operator, Hardy operator) in local spaces of the Morrie type was studied together with the staff of this Institute (V. S. Guliyev, H. V. Guliyev, R. Mustafayev). A full list of collaborations can be found here.

Accurate stability evaluation for the variation of eigenvalues of nonnegative selfadjoint elliptic operators of arbitrary even order when changing the open sets on which they are defined were obtain with P. D. Lamberti, M. Lanza de Cristoforis, Feleqi E. This evaluation is expressed in terms of Lebesgue measure of the symmetric difference of open sets. The boundary terms of Dirichlet and Neumann were analyzed.

A full list of joint works can be found here

Mathematicians of RUDN University (Professor B. Yu. Sternin, Professor A. Y. Savin) with mathematicians of the University of Hannover (Prof. Dr. Elmar Schrohe) analyze actual problems of elliptic theory and noncommutative geometry in joint scientific works. In particular, an explicit uniformization for elliptic operators associated with groups of shift operators was found out. The terms for the Fredholm property of the operators associated with groups of quantized canonical transformations were obtained.

A.Yu. Savin, B.Yu. Sternin, E. Schrohe, “Index problem for elliptic operators associated with a diffeomorphism of a manifold and uniformization”, Proceedings of the Russian Higher School Academy of Sciences, 441:5 (2011), 593–596; A.Yu. Savin, B.Yu. Sternin, E. Schrohe, “Index problem for elliptic operators associated with a diffeomorphism of a manifold and uniformization”, Dokl. Math., 84:3 (2011), 846-849

A.Yu. Savin, B.Yu. Sternin, E. Schrohe, “On the Index Formula for an Isometric Diffeomorphism”, Journal of Mathematical Sciences, 201:6 (2014), 818–829

A.Yu. Savin, E. Schrohe, B. Sternin, “Uniformization and Index of Elliptic Operators Associated with Diffeomorphisms of a Manifold”, Russian Journal of Mathematical Physics, 22:3 (2015), “410–420”

Joint research work with D. Haroske, an employee of Friedrich Schiller University Jena. Evaluation of the uniform modulus of continuity for Bessel potentials, accurate evaluation of the majorant of modules of continuity and optimal embedding for generalized Bessel potentials were obtained, optimal Calderon space for Bessel potentials and optimal Calderon space for generalized Bessel potentials were built.

Goldman M.L., Haroske D. Estimates for continuity envelopes and approximation numbers of Bessel potentials // Journal of Approximation Theory. 2013. Vol. 172. P. 58–85.

Goldman M.L., Haroske D. Optimal Calderon spaces for the generalized Bessel potentials / // Doklady Mathematics. 2015. Vol. 92. № 1. P. 404–407.

We are working on the joint article “Spherical symmetric stationary solutions of the Vlasov – Poisson equation” with J. Batt, an employee of Ludwig Maximilian University of Munich.

Joint research work with H.-O.-Walther, an employee of Justus Liebig University. Sufficient terms of hyperbolicity and stability of periodic solutions of nonlinear functional-differential equations were obtained. The results of the work are reflected in the articles: - Walter H.-O., Skubachevskii A. L. On hyperbolicity of rapidly oscillating periodic solutions to functional differential equations. // Journal “Functional analysis and its applications”, Vol. 39, is. 1, M., 2005, p. 82-85. - Walter X-Skubachevskii A. L. On hyperbolicity of solutions with irrational periods of some functional differential equations. // Journal “Proceedings of the Russian Higher School Academy of Sciences”, Vol. 402. №2, M., 2005, p. 151-154.

Joint research work with W. Jäger, an employee of Heidelberg University. Results on the existence, uniqueness and periodicity of solutions in the case of the heat equation were obtained. It was proved that the existence of a periodic average solution implies the existence of a strong periodic solution with the same period. An example is given in which there is a single periodic average, and hence the only strong periodic solution. The results of the work are reflected in the article: P. Gurevich, W. Jäger, and A. Skubachevskii. On periodicity of solutions for thermocontrol problems with hysteresis-type switches. // SIAM J. Math. Anal. 41, No. 2, 2009, pp. 733-752.