  Creation of a black hole in quantum cosmology is the third way of black hole
formation. In contrast to the gravitational collapse from a massive body in
astrophysics or from the quantum fluctuation of matter fields in the very early
universe, in quantum cosmology scenario the black hole is essentially created
from nothing. The black hole originates from a constrained gravitational
instanton. The probability of creation for all kinds of single black holes in
the Kerr- Newman-de Sitter family, at the semi-classical level, is the
exponential of the total entropy of the universe, or one quarter of the sum of
both the black hole and the cosmological horizon areas. The de Sitter spacetime
is the most probable evolution at the Planckian era.
