Tidal Evolution with Internal Gravity Waves

Internal gravity waves (IGWs) exist in radiative zones inside a star, and when tidally excited by a nearby companion, they could cause efficient tidal dissipation with radiative damping, shaping the spin and orbital evolution of the system. In this talk, I will talk about their effects in different kinds of astrophysical systems. For a Wolf-Rayet-black-hole binary, tidally excited IGWs may efficiently transfer the orbital angular momentum to the Wolf-Rayet star, which may collapse to a fast-rotating black hole at the end of its lifetime. For binaries containing a sub-dwarf B (sdB) star, these waves may help them to achieve tidal synchronization, which can be directly compared to asteroseismic observations. When the mass of the companion is small, IGWs may trigger resonance locking, causing steady orbital migration of the companion, which might be found for planet hosts and extreme mass-ratio Wolf-Rayet binaries.