Physics 28 Atomic, Molecular, Optical and Plasma Physics 4 Atoms 4 Chemistry, Physical and theoretical 4 Complex Systems 4 Elementary Particles, Quantum Field Theory 4 Fluid- and Aerodynamics 4 Fluids 4 Mathematical Methods in Physics 4 Particles (Nuclear physics) 4 Quantum Physics 4 Quantum field theory 4 Quantum theory 4 Statistical Physics and Dynamical Systems 4 System theory 4 Astrophysics 3 Characterization and Evaluation of Materials 3 Engineering Fluid Dynamics 3 Fluid mechanics 3 Materials science 3 Mathematical physics 3 Physical Chemistry 3 Solid State Physics 3 Solid state physics 3 Astrophysics and Astroparticles 2 Classical Electrodynamics 2 Cosmology 2 Data Structures, Cryptology and Information Theory 2 Data structures (Computer science) 2 Dynamics 2