Speaker
Description
Extreme mass-ratio inspirals (EMRIs) are one of the most intriguing sources of gravitational waves. An EMRI binary consists of a stellar mass compact object falling into a supermassive black hole. Thanks to such a large disparity in scales, we can model these binaries, in first approximation, as a point particle (the ``secondary'') free-falling into the spacetime generated by the more massive companion. Corrections to the dynamics arise from radiation-reaction effects and the smaller body's spin.
In particular, the secondary spin introduces new degrees of freedom, and significantly affects the statistical accuracy of the other parameters, like the masses and the spin of the heavier object. Thus, including the secondary spin in the EMRI waveform is important to avoid biases on the inferred parameters.
In this talk, I will present a new method to compute fast and accurate gravitational waveform for extreme mass-ratio binaries with a spin-precessing secondary. Previous work in the literature directly solved the equations of motion for a spinning body, the MPD equations, in their original 2nd-order form.
Instead, we solve the MPD equations reduced to first-order form, which were derived using the Hamilton-Jacobi formalism. In this way, we can compute the trajectories very efficiently and accurately for generic orbits.
Moreover, we provide the spin-corrections to the frequencies in terms of one-dimensional integrals of Jacobi elliptic integrals. With the spin corrections to the trajectories at hand, we finally computed the EMRI waveform amplitudes and fluxes for generic orbits including, for the first time, the spin precession of the secondary.
