Speaker
Eduardo Guendelman
(Ben Gurion University)
Description
A new class of gravity-matter models defined
in terms of two independent non-Riemannian
volume forms (alternative generally covariant
integration measure densities) on the space-time
manifold are studied in some detail. These
models involve an additional R^2 (square
of the scalar curvature) term as well as
scalar matter field potentials of appropriate
form so that the pertinent action is invariant
under global Weyl-scale symmetry. Scale invariance
is spontaneously broken upon integration
of the equations of motion. After performing
transition to the physical Einstein frame
we obtain: (i) An effective potential for
the scalar field with two flat regions which
allows for a unified description of both
early universe inflation as well as of present
dark energy epoch; (ii) For a definite parameter
range the model possesses a non-singular
"emergent universe" solution which describes
an initial phase of evolution that precedes
the inflationary phase.
Primary author
Eduardo Guendelman
(Ben Gurion University)
