Congresses 24 Topology 17 Differential equations 14 Mathematics 13 Mathematical models 12 Mathematical analysis 11 Differential equations, Partial 10 Number theory 10 Algebra 9 Algebraic topology 9 Fluid dynamics 9 Geometry, Algebraic 9 Geometry, Differential 9 Numerical solutions 9 Functional analysis 8 Harmonic analysis 8 Stability 8 Numerical analysis 7 Quantum theory 7 Functions of complex variables 6 Hilbert space 6 Problems, exercises, etc 6 Representations of groups 6 Set theory 6 Stochastic processes 6 Algebras, Linear 5 Approximation theory 5 Categories (Mathematics) 5 Differentiable dynamical systems 5 Linear algebraic groups 5