Contents

Computational Mathematics and Mathematical Physics

Vol. 61, No. 3, 2021

General Numerical Methods

On the Calculation of the T-Congruence Centralizer

Kh. D. Ikramov p. 347  abstract

Difference Schemes Based on the Laguerre Transform

A. F. Mastryukov p. 351  abstract

Optimal Control

Dynamic Discrepancy Method in the Problem of Reconstructing the Input of a System with Time Delay Control

M. S. Blizorukova and V. I. Maksimov p. 359  abstract

Gradient Projection Method for a Class of Optimization Problems with a Constraint in the Form of a Subset of Points of a Smooth Surface

Yu. A. Chernyaev p. 368  abstract

Ordinary Differential Equations

Reduced SIR Model of COVID-19 Pandemic

S. I. Vinitsky, A. A. Gusev, V. L. Derbov, P. M. Krassovitskiy, F. M. Pen’kov and G. Chuluunbaatar p. 376  abstract

Partial Differential Equations

Inverse Problem of Determining the Absorption Coefficient in a Degenerate Parabolic Equation in the Class L∞

V. L. Kamynin p. 388  abstract

Bifurcations of Self-Oscillatory Solutions to a Nonlinear Parabolic Equation with a Rotating Spatial Argument and Time Delay

E. P. Kubyshkin and V. A. Kulikov p. 403  abstract

Analytical Inversion of the Operator Matrix for the Problem of Diffraction by a Cylindrical Segment in Sobolev Spaces

S. I. Eminov p. 424  abstract

Exact Solutions of the KdV Equation with Dual-Power Law Nonlinearity

Fibay Urbain, N. A. Kudryashov, E. Tala-Tebue, Malwe Boudoue Hubert, S. Y. Doka and Kofane Timoleon Crepin p. 431  abstract

Mathematical Physics

Analysis of Two-Fluid Plasma in the Electromagnetic Hydrodynamics Approximation and Discontinuous Structures in Their Solutions

I. B. Bakholdin p. 436  abstract

On the Interaction of Relativistic Colliding Jets of Neutral Dense Plasma

S. L. Ginzburg, V. F. Dyachenko, L. I. Mikhailova, V. M. Chechetkin and N. N. Fimin p. 453  abstract

Inviscid Suspension Flow along a Flat Boundary

O. B. Gus’kov p. 470  abstract

Numerical Simulation of Two-Dimensional Gas Flows through Granular Phase Change Materials

N. A. Lutsenko and S. S. Fetsov p. 480  abstract

The Effect of Weak Mutual Diffusion on Transport Processes in a Multiphase Medium

A. V. Nesterov p. 494  abstract