Ðð Àóðð× Òò Aeù Blockinðððö Ýòòññ Blockin×

Supermassive black holes inhabit galactic nuclei, and their presence influences in crucial ways the evolution of the stellar distribution. The low-density cores observed in bright galaxies are probably a result of black hole infall, while steep density cusps like those at the Galactic center are a result of energy exchange between stars moving in the gravita-tional field of the single black hole. Loss-cone dynamics are substantially more complex in galactic nuclei than in globular clusters due to the longer relaxation times, which permit a wider variety of geometries and orbital populations. The rate of star-black hole interactions has begun to be constrained through observations of energetic events associated with stellar tidal disruptions.