3.c Quantum Field Theory in
Curved Spaces
Quantum Field Theory in Curved Spaces deals with
the study and elaboration of field theory in incomplete manifolds (manifolds
with event and coordinate horizons) and its relation to the so-called Fulling-Unruh-Hawking
effect. Within this general framework, the following research lines are
important in our Group:
-
Study of the 10 coordinate systems that, in two-dimensional
space-time, induce the separability of Klein-Gordon equation.
-
Quantum Field Theory in non-inertial reference frames.
-
Regularization of the energy-momentum tensor of matter.
-
Casimir effect and other vacuum quantum effects in primordial
cosmology.
With regard to this last item, the main goals can
be listed as follows:
-
Investigation of the initial vacuum state of the Universe
and searching for preferred vacuum sets showing non-singular behavior of
the energy-momentum tensor of a quantum field theory in primordial times.
-
Calculation of the complete energy-momentum tensor of
a quantum field theory, in a preferred vacuum state, and determination
of the back-reaction effect of the vacuum energy density and pressure
upon the cosmological expansion.
-
Examination of the Casimir vacuum energy density in
space-times with non-trivial topology, including multiple cosmic-string
space-times, and comparison with results obtained with vacuum energy due
to particle creation and vacuum polarization effects in non-trivial geometrical
configurations, and its possible application in wormhole generation.
-
Creation of a cosmological scenario in which the transition
between inflationary and Friedman evolution phases is driven by quantum
vacuum effects of a field therory through Einstein equations.
-
Detailed examination of the Hawking black hole radiation
to verify the continued vality of the hypothesis used in its formulation.
We shall also study the issue of the origin of the cosmological
constant. Recently, a relation between the cosmological constant and certain
quantum aspects of the primitive universe was advanced (Barcelos,
Novello e Salim, Class. Q. Grav. 18, 1 (2001)). In this model the chiral
anomaly was used to obtain a dependence of the cosmological constant with
time. We will develop in this project some consequences of this scenario,
and we shall also study possible effects of the quantum phase of the universe
on observable quantities in cosmology.