1,415 research outputs found
Generalized Teleparallel Theory
We construct a theory in which the gravitational interaction is described
only by torsion, but that generalizes the Teleparallel Theory still keeping the
invariance of local Lorentz transformations in one particular case. We show
that our theory falls, to a certain limit of a real parameter, in the
Gravity or, to another limit of the same real parameter, in a
modified Gravity, interpolating between these two theories and still can
fall on several other theories. We explicitly show the equivalence with
Gravity for cases of Friedmann-Lemaitre-Robertson-Walker flat
metric for diagonal tetrads, and a metric with spherical symmetry for diagonal
and non-diagonal tetrads. We do still four applications, one in the
reconstruction of the de Sitter universe cosmological model, for obtaining a
static spherically symmetric solution type-de Sitter for a perfect fluid, for
evolution of the state parameter and for the thermodynamics to
the apparent horizon.Comment: 15 pages. arXiv admin note: text overlap with arXiv:1503.07427,
arXiv:1503.0785
Regular black holes in gravity
In this work, we study the possibility of generalizing solutions of regular
black holes with an electric charge, constructed in general relativity, for the
theory, where is the Gauss-Bonnet invariant. This type of solution
arises due to the coupling between gravitational theory and nonlinear
electrodynamics. We construct the formalism in terms of a mass function and it
results in different gravitational and electromagnetic theories for which mass
function. The electric field of these solutions are always regular and the
strong energy condition is violated in some region inside the event horizon.
For some solutions, we get an analytical form for the function. Imposing
the limit of some constant going to zero in the function we recovered
the linear case, making the general relativity a particular case.Comment: 22 pages, 25 figures.Version published in EPJ
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