Sara Gliorio: "Asymmetric binaries and scalar charges: an inspiral journey from fluxes to waveforms to data analysis"

Wednesday 20 May 2026, 12:30 → 14:00 Europe/Rome

The LISA satellite, recently adopted by ESA, is ready 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), composed by a massive black hole and a stellar mass secondary, are among the most peculiar of such new family 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. Such long evolution is key to provide a measurement of the source parameters with exceptional accuracy, and to allow precise tests of vacuum General Relativity scenarios.
In this talk, I will investigate a beyond-General Relativity scenario in which the secondary compact object carries a scalar charge. I will describe how to compute the scalar energy fluxes emitted by such EMRIs when the secondary follows generic (eccentric and inclined) orbits. This is achieved using a new C++ code, STORM (Scalar-Tensor Orbital Radiation from EMRIs), which computes both scalar and gravitational energy fluxes.
I will then show how standard EMRI waveforms, generated with FEW within General Relativity, can be extended to incorporate the additional scalar radiation induced by the scalar charge.
Finally, I will study LISA’s ability to constrain the scalar charge in asymmetric binaries using both Fisher matrix forecasts and MCMC simulations. Fisher matrices allow us to explore broadly how the constraints depend on the intrinsic binary parameters, covering both EMRI and IMRI systems, while MCMC simulations are used to validate these results and provide a more robust estimate of the expected constraints.