Spinning black holes could expose exotic particles - space - 29 July 2010 - New Scientist

Spinning black holes could expose exotic particles - space - 29 July 2010 - New Scientist: "According to the team's calculations, a single axion emitted by a spinning black hole could trigger the emission of more axions to form a cloud orbiting the black hole. The creation of each axion would draw rotational energy away from the hole. The cloud eventually gets so dense that some of it will collapse and fall into the hole while the rest is flung outwards and may escape the black hole's gravitational field altogether."