Functional analysis Topology Functional Analysis 58 Differential Equations 10 Differential equations 10 Mathematical optimization 10 Operator Theory 10 Operator theory 10 Probabilities 9 Probability Theory 9 Measure and Integration 8 Measure theory 8 Analysis 6 Calculus of Variations and Optimization 6 Calculus of variations 6 Mathematical Logic and Foundations 6 Mathematical analysis 6 Mathematical logic 6 Lie groups 5 Topological Groups and Lie Groups 5 Topological groups 5 Geometry 4 Optimization 4 Algebra 3 Approximation theory 3 Approximations and Expansions 3 Functions of real variables 3 Real Functions 3 Abstract Harmonic Analysis 2 Algebraic Topology 2