The new, groundbreaking EHT results have given us direct images of the regions just outside the event horizon of two supermassive black holes, and yet our ability to test GR is still very dependent on uncertainties about the complicated accretion geometry and plasma/radiative properties. Simply put, we still do not know how to predict what comes out of a BH (outflows, light/particles) as a function of what goes in (accretion inflow).
As for many fields, one of the key impediments to progress is that it requires overcoming some ‘disconnects’ that have evolved between communities and methods, particularly between phenomenological data interpretation and more a priori theoretical models. In this very interactive meeting run using the ‘unconference’ style, we bring junior/developing and senior experts together to discuss questions such as:
1) how can we reconcile GRMHD simulations with older paradigms such as the “corona”,
2) what needs to change in our models to account for the latest spectral-timing information and reverberation mapping/lags?
3) What is the role of magnetic fields in driving state changes and variability,
4) can we agree on some basic aspects of the accretion geometry given the new information we have from direct imaging, X-ray polarimetry and spectral-timing?,
5) how can we better understand how plasma microphysics lead to larger scale properties
6) can we think of new ways to constrain black hole mass and spin?