I.N. Sneddon – författare

Mathematical Analysis: A Special Course focuses on the study of mathematical analysis. The book first discusses set theory, including operations on sets, countable sets, equivalence of sets, and sets of the power of the continuum. The text also discusses the elements of the theory of metric and normed linear spaces. Topics include convergent sequences and closed sets; theorem of the fixed point; normed linear spaces; and continuous functions and compact spaces. The selection also discusses the calculus of variations; the theory of the integral; and geometry of Hilbert space. The text also covers differentiation and integration, including functions of bounded variation, derivative of a non-decreasing function, differentiation of functions of sets, and the Stieltjes integral. The book also looks at the Fourier transform. Topics include convergence of Fourier series; Laplace transform; Fourier transform in the case of various independent variables; and quasi-analytic classes of functions. The text is a valuable source of data for readers interested in the study of mathematical analysis.

Operational Calculus, Volume II is a methodical presentation of operational calculus. An outline of the general theory of linear differential equations with constant coefficients is presented. Integral operational calculus and advanced topics in operational calculus, including locally integrable functions and convergence in the space of operators, are also discussed. Formulas and tables are included. Comprised of four sections, this volume begins with a discussion on the general theory of linear differential equations with constant coefficients, focusing on such topics as homogeneous and non-homogeneous equations and applications of operational calculus to partial differential equations. The section section deals with the integral of an operational function and its applications, along with integral transformations. A definition of operators in terms of abstract algebra is then presented. Operators as generalized functions, power series of operators, and Laplace transform are also discussed. Formulas of the operational calculus and tables of functions round out the book. This monograph will be useful to engineers, who regard the operational calculus merely as a tool in their work, and readers who are interested in proofs of theorems and mathematical problems.

This monograph deals with some of the latest results in nonlinear mechanics, obtained recently by the use of a modernized version of Bogoljubov's method of successive changes of variables which ensures rapid convergence. This method visualised as early as 1934 by Krylov and Bogoljubov provides an effective tool for solving many interesting problems of nonlinear mechanics. It led, in particular, to the solution of the problem of the existence of a quasi­ periodic regime, with the restriction that approximate solutions obtained in the general case involved divergent series. Recently, making use of the research of Kolmogorov and Arno'ld, Bogoljubov has modernised the method of successive substitutions in such a way that the convergence of the corresponding expansions is ensured. This book consists of a short Introduction and seven chapters. The first chapter presents the results obtained by BogoIjubov in 1963 on the extension of the method of successive substitutions and the study of quasi­ periodic solutions applied to non-conservative systems (inter alia making explicit the dependence of these solutions on the parameter, indicating methods of obtaining asymptotic and convergent series for them, etc.).