Kashin, B. S.; Saakyan, A. A. Orthogonal series. Transl. from the Russian by Ralph P. Boas. Transl. ed. by Ben Silver. (English) Zbl 0668.42011 Translations of Mathematical Monographs, 75. Providence, RI: American Mathematical Society (AMS). xii, 451 p. $ 146.00 (1989). For a review of the Russian original (1984) see Zbl 0632.42017.In this book we present the fundamental methods of the theory of orthogonal series. We study general orthonormal systems as well as specific systems (for example, the Haar and Franklin systems). We present both, classical results and those obtained more recently. All propositions that fall outside the scope of university courses are provided with full proofs. Contents: Introductory concepts and some general results. Independent functions and their first applications. The Haar systems. Some results on the trigonometric and Walsh systems. The Hilbert transform and some function spaces. The Faber-Schauder and Franklin systems. Orthogonalization and factorization theorems. Theorems on the convergence of general orthogonal series. General theorems on the divergence of orthogonal series. Some theorems on the representation of functions by orthogonal series Cited in 4 ReviewsCited in 67 Documents MSC: 42C05 Orthogonal functions and polynomials, general theory of nontrigonometric harmonic analysis 42-02 Research exposition (monographs, survey articles) pertaining to harmonic analysis on Euclidean spaces 42A38 Fourier and Fourier-Stieltjes transforms and other transforms of Fourier type 42A20 Convergence and absolute convergence of Fourier and trigonometric series Keywords:orthogonal series; Haar system; Fourier series; Franklin systems PDF BibTeX XML Cite \textit{B. S. Kashin} and \textit{A. A. Saakyan}, Orthogonal series. Transl. from the Russian by Ralph P. Boas. Transl. ed. by Ben Silver. Providence, RI: American Mathematical Society (1989; Zbl 0668.42011)