Operator theory 16 Mathematical analysis 6 Differential equations, Partial 5 Linear operators 5 Clifford algebras 4 Congresses 4 Functional analysis 4 Integral equations 4 Mathematical physics 4 Approximation theory 3 Banach spaces 3 Commutative algebra 3 Fourier analysis 3 Function spaces 3 Hamiltonian systems 3 History 3 Interpolation 3 Mathematics 3 Matrices 3 Numerical solutions 3 Spectral theory (Mathematics) 3 Stochastic processes 3 Asymptotic theory 2 Coding theory 2 Control theory 2 Control theory.1 2 Data processing 2 Differential equations, Nonlinear 2 Functions of complex variables 2 Geometry, Differential 2