Linear waves Group velocity, dispersion Geometrical optics Linear Korteveg–de Vrise equation and its exact solution Some examples: plasma ion sound, shallow water waves Foundations of group theory Spatial symmetry of Schrodinger equation Group representations, regular representation Direct product of representations Schur’s lemma Burnside's theorem, representation characters Cosets, classes of conjugate elements Applications of group theory to atomic spectra Splitting of atomic spectra terms in electric field Spin-orbit interaction Spinor representations of point groups Time-reversal symmetry Small oscillations Mechanical and oscillatory representation Determination of normal modes Classification of oscillations of polyatomic molecules Jahn-Teller effect Crystals Translation group Elements of point symmetry group Admissible symmetry elements of crystalline solids Improper translations Symmorphic and non-symmorphic symmetry groups Translation group representation Bloch's theorem, reciprocal lattice, Brillouin zones Construction of space group representation Wave vector star, wave vector group Irrreducible representations of non-symmorphic groups and projective representations Symmetric degeneracy in solids kp-method of perturbation theory, effective mass tensor Dispersion law near higher symmetry point, band splitting due to spin-orbit interaction   LITERATURE: G.Ya. Lubarsky. Group Theory and its Applications to Physics R.S. Knox, A. Gold. Symmetry in Solids M. Hamermesh. Group Theory and its Applications to Physical Problems G.L. Bir, G.E. Pikus. Symmetry and Distortion Phenomena in Semiconductors G. Streitwolf. Group Theory in Solid State Physics G. Birman. Spatial Symmetry and Optical Properties of Solids