Functional Analysis Functional analysis 330 Partial Differential Equations 91 Partial differential equations 91 Operator Theory 90 Operator theory 90 Analysis 60 more ... Analysis (Mathematics) 60 Mathematical analysis 60 Functions of complex variables 38 Probabilities 37 Probability Theory and Stochastic Processes 37 Mathematical Methods in Physics 36 Physics 36 Fourier Analysis 32 Fourier analysis 32 Functions of a Complex Variable 31 Abstract Harmonic Analysis 29 Applied mathematics 29 Engineering mathematics 29 Harmonic analysis 29 Calculus of Variations and Optimal Control; Optimization 26 Calculus of variations 26 Mathematical physics 24 Algebra 22 Approximation theory 22 Approximations and Expansions 22 Applications of Mathematics 21 Differential equations 20 Ordinary Differential Equations 20 less ...