The Leonard E Parker Center for Gravitation, Cosmology and Astrophysics holds frequent seminars on a broad range of ongoing cosmology and gravitation research topics. Unless otherwise noted, seminars are on Friday afternoons at 1:00 PM in KIRC 2175; there is a gathering for a brown bag lunch at 12:30.

Three-mode instabilities from exoplanets to gravitational waves or how I learned to stop worrying and love nonlinear dynamics
Reed Essick, Massachusetts Institute of Technology

Weakly nonlinear systems are ubiquitous throughout nature. I explore the impact of 3-mode interactions, corresponding to the lowest order nonlinearity one might expect, in two disparate astrophysical contexts. First, resonant 3-mode interactions within Sun-like stars can be excited by close exoplanets and may explain the dearth of short period/high mass hot Jupiters. Second, non-resonant interactions within neutron stars in compact binaries are driven throughout the gravitational wave inspiral. This extra source of dissipation modifies the gravitational waveform’s phase and should be detectable with current instruments assuming reasonable saturation profiles. While detectability in binary neutron star systems will be discussed in some details, the impact of nonlinear tides in both systems should be observable over the next decade. The audience will also learn the difference between gravity waves and gravitational waves.