  In this paper we follow a new approach for particle creation by a localized
strong gravitational field. The approach is based on a definition of the
physical vacuum drawn from Heisenberg uncertainty principle. Using the fact
that the gravitational field red-shifts the frequency modes of the vacuum, a
condition on the minimum stregth of the gravitational field required to achieve
real particle creation is derived. Application of this requirement on a
Schwartzchid black hole resulted in deducing an upper limit on the region,
outside the event horizon, where real particles can be created. Using this
regional upper limit, and considering particle creation by black holes as a
consequence of the Casimir effect, with the assumption that the created quanta
are to be added to the initial energy, we deduce a natural power law for the
development of the event horizon, and consequently a logarithmic law for the
area spectrum of an inflating black hole. Application of the results on a
cosmological model shows that if we start with a Planck-dimensional black hole,
then through the process of particle creation we end up with a universe having
the presently estimated critical density. Such a universe will be in a state of
eternal inflation.
