Speaker
Description
The LISA satellite, recently adopted by ESA, is set to open a new gravitational wave window, targeting sources that are inaccessible to ground-based detectors like LIGO and Virgo. Extreme mass-ratio inspirals (EMRIs), consisting of a massive black hole and a stellar-mass secondary, are among the most distinctive members of this new class of binaries. The inspiral phase of these systems falls within the mHz regime of the LISA band. Depending on their mass ratios, EMRIs will be continuously observed over long periods, ranging from months to years. This prolonged evolution is key to enabling exceptionally precise measurements of source parameters and performing stringent tests of gravity. In this talk, I consider a beyond-GR scenario in which the secondary compact object carries a scalar charge. I show how to compute the scalar energy fluxes emitted by such EMRIs when the secondary follows generic orbits—both eccentric and inclined. This computation is carried out using a new C++ code, MEW (Modified EMRI Waveforms), which calculates both scalar and gravitational energy fluxes.
I present the first results obtained with this code. The total energy flux is decomposed into a sum over radial, polar, and azimuthal modes. I show the spectra of these scalar fluxes, a crucial first step toward efficient mode summation. Additionally, I present preliminary results on the detectability of the scalar charge in asymmetric binaries, and discuss how constraints on this scalar charge depend on the mass ratio.