• Fourier coefficients; approximate identities; approximate identities; approximate identities and pointwise convergence; square integrable functions; convergence of Fourier series in norm; local convergence; characterization of Fourier coefficients; Hilbert transform; approximate identities. Triangular schemes; elements of best approximation; poisson integrals and hardy spaces; conjugation of approximate identities; Szego-Kolmogoriv-theorem; absolute convergence of Fourier series; Fourier transform on R; plancherel transform on R; poisson summation-formula.

". . .an excellent introduction. . ..warmly recommended to everyone who wants to make a quick acquaintance with Fourier series. "---Zentralblatt fur Mathematik