Physics 1,601 Quantum theory 436 Quantum mechanics; Physics 369 Mathematical physics 309 Solid state physics; Properties of matter 235 Mechanics 208 Nuclear physics 169 Thermodynamics 160 Atomic and Nuclear physics 152 Quantum mechanics 128 Solid state physics 115 Optics 105 Statistical mechanics 96 Dissertations, Academic (Ph.D) 91 Thesis (Ph.D)-Physics 89 Particles (Nuclear physics) 86 Statistical physics; Classical mechanics 86 Plasma physics; Properties of matter 71 Theoretical physics 69 Quantum field theory 67 Plasma (Ionized gases) 63 Magnetism 61 Modern physics 58 Dynamics 53 Electromagnetism 53 Statistical physics 51 Theory of relativity; Physics 51 Electrodynamics 50 Science 49 Semiconductors 48