1,750 research outputs found
Thick brane models in generalized theories of gravity
This work deals with thick braneworld models, in an environment where the
Ricci scalar is changed to accommodate the addition of two extra terms, one
depending on the Ricci scalar itself, and the other, which takes into account
the trace of the energy-momentum tensor of the scalar field that sources the
braneworld scenario. We suppose that the scalar field engenders standard
kinematics, and we show explicitly that the gravity sector of this new
braneworld scenario is linearly stable. We illustrate the general results
investigating two distinct models, focusing on how the brane profile is changed
in the modified theories.Comment: 8 pages, 8 figures. To appear in PL
First-order formalism for twinlike models with several real scalar fields
We investigate the presence of twinlike models in theories described by
several real scalar fields. We focus on the first-order formalism, and we show
how to build distinct scalar field theories that support the same extended
solution, with the same energy density and the very same linear stability. The
results are valid for two distinct classes of generalized models, that include
the standard model and cover a diversity of generalized models of current
interest in high energy physics.Comment: 9 pages; Version to appear in EPJ
Braneworld solutions for F(R) models with non-constant curvature
This work deal with braneworld scenarios with generalized gravity. We
investigate models where the potential of the scalar field is polynomial or
nonpolynomial. We obtain exact and approximated solutions for the scalar field,
warp factor and energy density, in the complex scenario with no restriction on
the scalar curvature. In particular, we describe the case where the brane may
split, engendering internal structure, with the splitting caused by the same
parameter that controls deviation from standard gravity.Comment: 9 pages, 7 figures; new versio
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