Neutron Stars in the Effective Fly-By Framework: $f$-Mode Re-summation

Understand

Eccentric compact binaries pose not only a challenge for gravitational wave detectors, but also provide a probe into the nuclear equation of state if one of the objects is a neutron star.

• At the short pericenter passage, tidal interactions excite f-modes on the star, which in turn emit their own gravitational waves.
• We derive an analytic waveform for these stellar oscillations within the effective fly-by framework, modeling the emission to leading post-Newtonian order.
• At this order, the f-mode response can be written in a Fourier decomposition in terms of orbital harmonics, with the amplitudes of each harmonic depending on Hansen coefficients.