42XX 


Harmonic analysis on Euclidean spaces 

42Axx 

Harmonic analysis in one variable 


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 