325 research outputs found
Dark side of the universe in the Stephani cosmology
We investigate the late time acceleration of the universe in the context of
the Stephani model. This solution generalizes those of
Friedmann-Lemaitre-Robertson-Walker (FLRW) in such a way that the spatial
curvature is a function of of time. We show that the inhomogeneity of the
models can lead to an accelerated evolution of the universe that is analogous
to that obtained with FLRW models through a cosmological constant or any exotic
component for matter.Comment: 8 pages, 2 figure, many improvements; to appear in European Physical
Journal
Exact String-like Solutions of the Gauged Nonlinear O(3) Model
We show that the least energy conditions in the gauged nonlinear sigma model
with Chern-Simons term lead to exact soliton-like solutions which have the same
features as domain walls. We will derive and discuss the corresponding
solutions, and compute the total energy, charge, and spin of the resulting
system.Comment: 7 pages, 5 figure
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