Subscribe now   Home |Space | News  Warm dark matter solves
mystery of giant black holes  Dark matter may be made of fast,
lightweight particles - contrary to the most widely accepted
theory, according to a new computer simulation. That could
explain the peculiarly pure chemical makeup of some stars in the
Milky Way, and the enormous mass of black holes that live at the
hearts of large galaxies.  Because dark matter reveals itself
only by its gravity, astronomers have few clues to its nature.
The most popular model is cold dark matter: heavy subatomic
particles that tend to move very slowly.  Another possibility is
warm dark matter: lighter particles that move faster. The rapid
motion of these particles smoothes out the small dense knots of
matter that would otherwise form in the cores of galaxies, and
there are hints that such dense knots are indeed missing.  Liang
Gao and Tom Theuns of Durham University in the UK have built a
computer simulation to compare the behaviour of cold and warm
dark matter in the e