42A05  Trigonometric polynomials, inequalities, extremal problems


42A10  Trigonometric approximation


42A15  Trigonometric interpolation


42A16  Fourier coefficients, Fourier series of functions with special properties, special Fourier series {For automorphic theory, see mainly 11F30}


42A20  Convergence and absolute convergence of Fourier and trigonometric series


42A24  Summability and absolute summability of Fourier and trigonometric series


42A32  Trigonometric series of special types (positive coefficients, monotonic coefficients, etc.)


42A38  Fourier and FourierStieltjes transforms and other transforms of Fourier type


42A45  Multipliers


42A50  Conjugate functions, conjugate series, singular integrals


42A55  Lacunary series of trigonometric and other functions; Riesz products


42A61  Probabilistic methods


42A63  Uniqueness of trigonometric expansions, uniqueness of Fourier expansions, Riemann theory, localization


42A65  Completeness of sets of functions


42A70  Trigonometric moment problems


42A75  Classical almost periodic functions, mean periodic functions [See also 43A60]


42A82  Positive definite functions


42A85  Convolution, factorization


42A99  None of the above, but in this section

