Uploaded July 2022 | Updated September 2026, 2 hours ago
Constraining two-spin effects in gravitational-wave data with an augmented definition of the precessing spin parameter χp
Spin precession is a key feature in the dynamics of black-hole binaries predicted by General Relativity. Misalignments between the black-hole spins and the binary’s orbital momentum induce characteristic modulations to the emitted gravitational waves which are intrinsically hard to estimate because they provide a highly subdominant contribution. The most commonly used quantity to track the amount of relativistic precession in current LIGO/Virgo observations is the so-called effective precession parameter χp. Here we exploit a recently developed re-definition of χp that considers all the variations occurring on the precession timescale, allowing to capture two-spin effects in a consistent fashion. In particular, sources with two precessing spins populate a dedicated region of the parameter space where χp less than 1. Using a large number of software injections in synthetic data, we recover the posterior distribution of such augmented χp parameter and identify the regions of the parameter space where present and future gravitational-wave interferometers could detect two-spin effects in black-hole binary data. Future advances in GW astronomy will allow to measure with an extremely high accuracy the waveform parameters, thus placing strong constraints on the underlying astrophysical processes.
Authors: Viola De Renzis, Davide Gerosa, Patricia Schmidt, Geraint Pratten
Presenter: Viola De Renzis
Constraining two-spin effects in gravitational-wave data with an augmented definition of the precessing spin parameter χp
Spin precession is a key feature in the dynamics of black-hole binaries predicted by General Relativity. Misalignments between the black-hole spins and the binary’s orbital momentum induce characteristic modulations to the emitted gravitational waves which are intrinsically hard to estimate because they provide a highly subdominant contribution. The most commonly used quantity to track the amount of relativistic precession in current LIGO/Virgo observations is the so-called effective precession parameter χp. Here we exploit a recently developed re-definition of χp that considers all the variations occurring on the precession timescale, allowing to capture two-spin effects in a consistent fashion. In particular, sources with two precessing spins populate a dedicated region of the parameter space where χp less than 1. Using a large number of software injections in synthetic data, we recover the posterior distribution of such augmented χp parameter and identify the regions of the parameter space where present and future gravitational-wave interferometers could detect two-spin effects in black-hole binary data. Future advances in GW astronomy will allow to measure with an extremely high accuracy the waveform parameters, thus placing strong constraints on the underlying astrophysical processes.
Authors: Viola De Renzis, Davide Gerosa, Patricia Schmidt, Geraint Pratten
Presenter: Viola De Renzis
