TY - JOUR A1 - Johnson, Michael D. A1 - Akiyama, Kazunori A1 - Blackburn, Lindy A1 - Bouman, Katherine L. A1 - Broderick, Avery E. A1 - Cardoso, Vitor A1 - Fender, Rob P. A1 - Fromm, Christian M. A1 - Galison, Peter A1 - Gómez, José L. A1 - Haggard, Daryl A1 - Lister, Matthew L. A1 - Lobanov, Andrei P. A1 - Markoff, Sera A1 - Narayan, Ramesh A1 - Natarajan, Priyamvada A1 - Nichols, Tiffany A1 - Pesce, Dominic W. A1 - Younsi, Ziri A1 - Chael, Andrew A1 - Chatterjee, Koushik A1 - Chaves, Ryan A1 - Doboszewski, Juliusz A1 - Dodson, Richard A1 - Doeleman, Sheperd S. A1 - Elder, Jamee A1 - Fitzpatrick, Garret A1 - Haworth, Kari A1 - Houston, Janice A1 - Issaoun, Sara A1 - Kovalev, Yuri Y. A1 - Levis, Aviad A1 - Lico, Rocco A1 - Marcoci, Alexandru A1 - Martens, Niels C. M. A1 - Nagar, Neil M. A1 - Oppenheimer, Aaron A1 - Palumbo, Daniel C. M. A1 - Ricarte, Angelo A1 - Rioja, María  J. A1 - Roelofs, Freek A1 - Thresher, Ann C. A1 - Tiede, Paul A1 - Weintroub, Jonathan A1 - Wielgus, Maciek T1 - Key science goals for the next-generation Event Horizon Telescope JF - Galaxies N2 - The Event Horizon Telescope (EHT) has led to the first images of a supermassive black hole, revealing the central compact objects in the elliptical galaxy M87 and the Milky Way. Proposed upgrades to this array through the next-generation EHT (ngEHT) program would sharply improve the angular resolution, dynamic range, and temporal coverage of the existing EHT observations. These improvements will uniquely enable a wealth of transformative new discoveries related to black hole science, extending from event-horizon-scale studies of strong gravity to studies of explosive transients to the cosmological growth and influence of supermassive black holes. Here, we present the key science goals for the ngEHT and their associated instrument requirements, both of which have been formulated through a multi-year international effort involving hundreds of scientists worldwide. KW - black holes KW - general relativity KW - interferometry KW - accretion KW - relativistic jets KW - very-long-baseline interferometry KW - EHT KW - ngEHT Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313525 SN - 2075-4434 VL - 11 IS - 3 ER -