  This paper discusses particle production in Schwarzchild-like spacetimes and
in an uniform electric field. Both problems are approached using the method of
complex path analysis. Particle production in Schwarzchild-like spacetimes with
a horizon is obtained here by a new and simple semi-classical method based on
the method of complex paths. Hawking radiation is obtained in the (t,r)
co-ordinate system of the standard Schwarzchild metric {\it without} requiring
the Kruskal extension. The co-ordinate singularity present at the horizon
manifests itself as a singularity in the expression for the semi-classical
propagator for a scalar field. We give a prescription whereby this singularity
is regularised with Hawking's result being recovered. In the case of the
electric field, standard quantum field theoretic methods can be used to obtain
particle production in a purely time-dependent gauge. In a purely
space-dependent gauge, however, the tunnelling interpretation has to be
resorted to. We attempt, in this paper, to provide a tunnelling description for
both the time and space dependent gauges. The usefulness of such a common
description becomes evident when `mixed' gauges, which are functions of both
space and time variables, are analysed. We report, in this paper, certain mixed
gauges which have the interesting property that mode functions in these gauges
are found to be a combination of {\it elementary} functions unlike the standard
modes. Finally, we present an attempt to interpret particle production by the
electric field as a tunnelling process between the two sectors of the Rindler
spacetime.
