Why High‐Spin Prograde MAD States Are Not Realized for AGN in Nature: Consequences for AGN Phenomenology

ABSTRACT Quasar‐like and other bright active galactic nuclei are typically radio quiet despite strong evidence that many host rapidly spinning black holes. In contrast, general relativistic magnetohydrodynamic (GRMHD) simulations show that high‐spin prograde black holes in magnetically arrested disk (MAD) states produce the most powerful relativistic jets. We show that these results are not in conflict but instead correspond to physically distinct and mutually limiting evolutionary pathways. If accretion proceeds through radiatively efficient thin disks, then as the innermost stable circular orbit decreases with increasing prograde spin, radiative output and radiation pressure rise sharply, driving strong disk winds that remove the conditions required for effective jet formation. In this branch, high‐spin prograde systems are therefore expected to be jet‐suppressed. Alternatively, if accretion transitions to radiatively inefficient flows capable of producing MAD states, then the spin‐up to near‐maximal prograde rotation proceeds on timescales that exceed the age of the universe for the relevant systems, preventing the realization of the extreme high‐spin prograde MAD configurations explored in GRMHD simulations. Within this framework, powerful jets need only be produced efficiently in counterrotating systems, not maximized there, preserving the time‐dependent spin evolution central to the counterrotation versus corotation paradigm of Garofalo, Evans & Sambruna. We thus reconcile GRMHD results with observations and provide a unified interpretation of the radio‐loud/radio‐quiet dichotomy and the cosmic evolution of powerful radio sources.