Poloidal magnetic fields extract energy from spinning versions of these objects in the (*) Blandford-Znajek process.
Aformuladescribingthedragontheseobjectsrelatesthederivativeofitsvelocitywithrespecttotimeto a quantity that is proportional to a stellar number density integral and the Coulomb logarithm. That formula is known as the "dynamical friction"(^)  formula. Examples of geometric systems that are used to describe these entities are the Gullstrand-Painlève and (+)  Eddington-Finkelstein coordinate systems. Poloidal magnetic fields extract energy from spinning versions of these objects in the (*) Blandford-Znajek process. Humanity very recently detected gravitational fluctuations resulting from an interacting pair of these objects merging some three billion light years away. For 10 points, name these entities which exhibit Hawking radiation near their event horizons.
Aformuladescribingthedragontheseobjectsrelatesthederivativeofitsvelocitywithrespecttotimeto a quantity that is proportional to a stellar number density integral and the Coulomb logarithm.
black holes