Torque wiggles -- a robust feature of the global disc-planet interaction

Understand

Gravitational coupling between planets and protoplanetary discs is responsible for many important phenomena such as planet migration and gap formation.

• The key quantitative characteristics of this coupling is the excitation torque density -- the torque (per unit radius) imparted on the disc by planetary gravity.
• Recent global simulations and linear calculations found an intricate pattern of low-amplitude, quasi-periodic oscillations in the global radial distribution of torque density in the outer disc, which we call torque wiggles.
• Here we show that torque wiggles are a robust outcome of global disc-planet interaction and exist despite the variation of disc parameters and thermodynamic assumptions (including $\beta$-cooling).