Lattice Dynamics: Vibrational Modes and Symmetry Relations

This lecture covers lattice dynamics, focusing on atoms displacing from equilibrium positions in the form of lattice vibrations. It discusses the properties affected by these vibrations, such as heat, specific heat, thermal expansion, and thermal conductivity. The lecture also explores the propagation of acoustic waves, the variation of relaxation time with temperature, and the essential role of lattice vibrations in superconductivity.