Functional analysis Functional Analysis 330 Operator theory 92 Partial Differential Equations 91 Partial differential equations 91 Operator Theory 90 Mathematical analysis 62 mer ... Analysis 60 Analysis (Mathematics) 60 Functions of complex variables 40 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 Engineering mathematics 30 Harmonic analysis 30 Abstract Harmonic Analysis 29 Applied mathematics 29 Approximation theory 26 Calculus of Variations and Optimal Control; Optimization 26 Calculus of variations 26 Mathematical physics 25 Algebra 24 Topology 23 Approximations and Expansions 22 Mathematical optimization 22 Applications of Mathematics 21 mindre ...