Fourier analysis Fourier Analysis 164 Analyse de Fourier 46 Harmonic analysis 44 Functional analysis 43 Functional Analysis 42 Differential Equations 38 Signal processing 37 Abstract Harmonic Analysis 36 Differential equations 36 Signal, Speech and Image Processing 34 Mathematics 33 MATHEMATICS 31 Applications of Mathematics 27 Mathematical analysis 24 Approximation theory 20 Analysis 19 Numerical analysis 19 Approximations and Expansions 18 Numerical Analysis 18 Functions of complex variables 17 Mathematical physics 17 Engineering mathematics 15 Operator theory 15 Engineering-Data processing 14 Mathematical and Computational Engineering Applications 14 Operator Theory 14 Mathematical Analysis 13 Probabilities 13 Probability Theory 13