Izv. Vyssh. Uchebn. Zaved. Mat., 1991, Number 11

JOURNALS // Izvestiya Vysshikh Uchebnykh Zavedenii. Matematika // Archive

1991, Number 11

	An approach to the study of approximation properties of linear operators Yu. G. Abakumov, V. G. Banin	3
	Universal form of writing the solution of a system of linear nonhomogeneous differential equations with constant coefficients A. A. Baloev	6
	Moduli of continuity of permutations, and multiplicative inequalities A. A. Budagov	13
	Extremal positive extensions of an infinite-dimensional analogue of the Krein–Feller differentiation operator A. N. Vernik, D. Z. Il'yazova	19
	The space of continuous functions, and box products I. I. Guran, M. M. Zarichnyi	22
	Absolute summability of orthogonal series by $(\varphi,\lambda)$ methods O. A. Ziza	25
	Fourier–Haar double series O. Kovachik	36
	Quasivarieties of representations of groups A. A. Matveev	39
	Optimization, on a nonfixed time interval, of differential inclusions with delay E. N. Makhmudov	43
	A nonclassical problem for a degenerate hyperbolic equation L. S. Pulkina	48
	Approximate conditions for optimality for a system described by a nonlinear parabolic equation S. Ya. Serovaĭskiĭ	52
	On the index of the operator of the Dirichlet problem in a domain with a piecewise-smooth or Radon boundary A. A. Soloviev	60
	Hermite–Padé approximations of sequential powers of a logarithm and their arithmetic applications V. N. Sorokin	66
	Some classes of optimization problems on a set of arrangements and their properties S. V. Yakovlev, I. V. Grebennik	74

Brief communications
	Representation of solutions of operator-differential equations of hyperbolic type in polynomial form V. V. Gorodestkii	87
	A variational maximum principle for pulse and singular regimes in an optimization problem that is linear with respect to control V. A. Dykhta	89
	Stability of hybrid control systems G. A. Egorov	91
	Asymptotics of eigenvalues for a class of nonuniformly elliptic operators N. A. Kvasova	94
	Weight conditions that guarantee the similarity of weighted Sobolev spaces under conformal mappings of domains T. G. Latfullin	96