Speakers
Description
We quantify the ability of LISA to test the presence of non-tensorial polarizations as well as modifications to the tensor ones in gravitational waves emitted from massive black hole binaries. We employ the Parametrized Post-Einsteinian (PPE) formalism to model deviations from General Relativity for tensor, vector, and scalar polarizations. Our PPE parametrization is inspired by post-Newtonian waveforms from four modified gravity theories: Horndeski, Einstein-aether, Rosen's bimetric, and Lightman-Lee. We consistently implement these modifications across the inspiral, merger, and ringdown phases, ensuring proper waveform alignment and tapering. Subsequently, we perform Fisher forecasts to derive expected constraints on deviations from General Relativity and map these constraints to the parameter spaces of the four gravity theories. This work demonstrates LISA's potential to probe gravity in the strong-field regime via gravitational wave polarizations.
https://docs.google.com/presentation/d/1PZfxtCBGAg2ewBgF7Xvf0UxwswceTPu39ztTY4U1k5M/edit?usp=sharing