wave propagation
any of the ways in which waves travel
radio propagation
behavior of radio waves as they travel, or are propagated, from one point to another, or into various parts of the atmosphere
slow light
propagation of an optical pulse at a very low group velocity
sound propagation
transmission of audio waves
dispersion relation
relation of wavelength/wavenumber as a function of a wave's frequency
interference
phenomenon in which two coherent waves combine into a resultant wave with greater intensity or lower amplitude