TESIFA · Tracking the Evolution and dynamicS of Intermediate-mass black holes to Forecast their upcoming observAtions

In the next few years, electromagnetic and gravitational-wave facilities will uncover the elusive population of intermediate-mass black holes (IMBHs), the likely progenitors of present-day supermassive black holes. The upcoming detections promise to revolutionise our understanding of the black-hole population across the cosmic epochs; in preparation for this exciting future, it is now fundamental to shed light on the debated dynamical processes governing the growth of IMBHs. TESIFA is the long-awaited program that will clarify the timespan black holes spend in the intermediate-mass range, thus allowing for a solid interpretation of the upcoming IMBH detections. Leveraging the emergent picture according to which IMBHs primarily grow via stellar accretion, TESIFA will numerically model the rates of tidal disruption events (TDEs, thousands of which will be detected by the Vera Rubin Observatory starting next year) and gravitational-wave-induced extreme mass ratio inspirals (EMRIs, accessible to the planned LISA mission) about IMBHs. By combining this approach with state-of-the-art observations of nearby stellar systems, TESIFA will place novel constraints on the local IMBH population. Furthermore, TESIFA will investigate the ratio between TDE and EMRI rates as a function of the host galaxy properties, so that the observed TDE rates could be used to forecast LISA EMRI rates. Overall, TESIFA will lay the foundation for understanding the IMBH demographics and best exploiting their upcoming observations.At Princeton University, the fellow will work alongside world-leading experts in the field of IMBH observations; she will learn the challenges affecting the observations of IMBHs and their hosts, as well as the capabilities and limits of electromagnetic facilities. The planned training will perfectly complement the fellows extensive numerical expertise, making her a well rounded scientist and placing her at the forefront of the research targeting IMBHs.