Host: Bekki Dawson

Abstract: High-eccentricity (high-e) migration is an important channel for the formation of hot Jupiters (HJs). In this scenario, a giant planet is excited onto a very eccentric orbit that decays and circularizes on Gyr timescales due to tidal effects. Previous studies of high-e migration have use parameterized treatments of weak tidal friction and overlooked critical contributions from dynamical tides. These studies have suggested that high-e migration can reproduce multiple features of the observed HJ population but that it struggles to explain the frequency of observed HJs without assuming that young gas giants are many times as dissipative as Jupiter. I demonstrate that the inclusion of chaotic dynamical tides can help resolve this issue. For sufficiently large eccentricity and small pericenter distance, tidally excited modes in the planet can grow chaotically over multiple pericenter passages and eventually dissipate non-linearly, drawing energy from the orbit and rapidly shrinking the semimajor axis. These chaotic tides endow high-e migration with several favorable features to explain observations of HJs. They can also be important in other astrophysical situations that involve a highly eccentric orbit, e.g. tidal capture in a dense stellar cluster or a precursor of stellar disruption by a massive black hole.