Operator Theory Operator theory 222 Functional Analysis 90 Functional analysis 90 Partial Differential Equations 53 Partial differential equations 53 Analysis 31 more ... Analysis (Mathematics) 31 Mathematical analysis 31 Functions of complex variables 30 Probabilities 25 Probability Theory and Stochastic Processes 25 Functions of a Complex Variable 23 Algebra 22 Mathematical physics 22 Differential equations 21 Ordinary Differential Equations 21 Mathematical Methods in Physics 20 Physics 20 Numerical Analysis 19 Numerical analysis 19 Dynamical Systems and Ergodic Theory 17 Dynamics 17 Ergodic theory 17 System theory 17 Integral Equations 16 Integral equations 16 Systems Theory, Control 15 Abstract Harmonic Analysis 14 Approximation theory 14 less ...