  We study the effects of the presence of the tachyon field around the black
hole. We show that in presence of the tachyon field, unlike the ordinary
canonical scalar field, the time evolution of the black hole mass depends on
the potential of this field. By considering several types of potential, we
study the behavior of the black hole mass and its time evolution and find some
interesting results. We find that the presence of the tachyon field causes the
accretion of the mass into the black hole. We also show that with linear and
hilltop potentials, in some ranges of the parameters space, the mass of the
black hole can decrease even without any Hawking radiation.
