Stochastic Rewind and fast-forward: calibrating LISA with LIGO's black holes and stochastic background

The direct detection of gravitational waves from binary stellar-mass black hole systems in our Universe provides a wealth of astrophysical information which is now within our reach.

These binaries merge in the LIGO and Virgo detector frequency sensitivity bands, and were once sweeping through the LISA band, emitting at much lower frequencies.

In LIGO, the binary mergers appear both as single, resolved events and as a multitude of incoherent signals, known as the stochastic gravitational-wave background.

In LISA, a similar picture will be seen, where a few binaries are directly resolved, while the vast majority build up a stochastic signal.

With StochRewind, we will draw out all binary black hole information measured by LIGO and Virgo to calibrate the LISA mission, providing a crucial ingredient for LISA data analysis methods.

First, we focus on the stochastic background in LIGO, and deliver a brand new pipeline which maximises our chances for detection.

Then, we analyse the implications of the LIGO black hole detections and stochastic background for LISA, delivering the first data-based prediction of the LISA binary black hole stochastic background, fully exploiting our multi-band gravitational-wave knowledge.It is essential that StochRewind be hosted by an institute which can supplement the fellow's first-hand experience in stochastic LIGO data analysis with knowledge on black hole population analysis and LISA astrophysics.

UniMiB is a unique institution which counts top experts in both these fields, providing an environment which bridges the gap between LISA and LIGO.

These revolutionary science objectives will be paired with advanced training objectives tailored to the fellow's personal career development plan, rooted in what UniMiB and the collaborations have to offer. StochRewind will have far-reaching impacts on the community, which will reap the benefits for decades to come.