Imaging nearby supermassive black holes and their immediate neighborhoods with millimeter-VLBI

Imaging nearby supermassive black holes and their immediate neighborhoods provides a new astrophysical laboratory to test general relativity in a strong gravitational field regime and probe the physical processes of mass accretion and jet genesis on event horizon scales. Very Long Baseline Interferometry at millimeter wavelengths offers the highest spatial resolution achievable in astronomy. In recent years, mm-VLBI, represented by the Event Horizon Telescope (EHT), has made unprecedented progress towards imaging nearby supermassive black holes. The recent release of the first-ever black hole image by the EHT collaboration marks a new culmination of decades of global effort, which provides the first visual evidence for the existence of black holes and a direct test of general relativity in a strong field. In this talk, I will discuss some recent progress and future opportunities in imaging the central engines of nearby Active Galactic Nuclei.