19 research outputs found
Thin-shell wormholes in -dimensional gravity
In this work, spherically symmetric thin-shell wormholes with a conformally
invariant Maxwell field for -dimensional gravity and constant scalar
curvature are built. Two cases are considered: symmetric wormholes and
asymmetric ones in the scalar curvature. Their stability under radial
perturbations is analyzed, finding stable solutions made of exotic matter for a
given range of the parameters.Comment: 18 pages, 6 figures; improved version with new reference
Thin-shell wormholes with charge in F(R) gravity
In this article, we construct a class of constant curvature and spherically
symmetric thin-shell Lorentzian wormholes in F(R) theories of gravity and we
analyze their stability under perturbations preserving the symmetry. We find
that the junction conditions determine the equation of state of the matter at
the throat. As a particular case, we consider configurations with mass and
charge. We obtain that stable static solutions are possible for suitable values
of the parameters of the model.Comment: 10 pages, 2 figures; v2: minor changes, 1 new reference adde
Thin-shell wormholes with a double layer in quadratic F(R) gravity
We present a family of spherically symmetric Lorentzian wormholes in
quadratic F(R) gravity, with a thin shell of matter corresponding to the
throat. At each side of the shell the geometry has a different constant value
of the curvature scalar R. The junction conditions determine the equation of
state between the pressure and energy density at the throat, where a double
layer is also located. We analyze the stability of the configurations under
perturbations preserving the spherical symmetry. In particular, we study
thin-shell wormholes with mass and charge. We find that there exist values of
the parameters for which stable static solutions are possible.Comment: 12 pages, 2 figures; v3: improved version, 1 new reference adde
Thin shells surrounding black holes in F(R) gravity
In this article, we consider spherical thin shells of matter surrounding black holes in F(R) theories of gravity. We study the stability of the static configurations under perturbations that conserve the symmetry. In particular, we analyze the case of charged shells outside the horizon of non-charged black holes. We obtain that stable static thin shells are possible if the values of the parameters of the model are properly selected.Fil: Eiroa, Ernesto Fabian. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Figueroa Aguirre, Griselda Verónica. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; Argentin
Black hole solutions and thin shells in N-dimensional F(R) gravity with a conformally invariant Maxwell field
We present a generalization of the black hole solutions with spherical
symmetry already known in the literature for -dimensional gravity
with a conformally invariant Maxwell field. We also introduce the formalism for
the construction of a broad family of spherically symmetric thin shells in this
theory. We use these generalized solutions in order to provide examples of
bubbles and thin layers of matter surrounding black holes. We analyze the
stability of the constructions under perturbations preserving the symmetry,
finding that stable configurations are possible for suitable values of the
parameters. We show that the extension to higher dimensions does not alter the
qualitative behavior of the thin shells found in four dimensions, with the main
difference being a change of scale for the different values of .Comment: 17 pages, 4 figures; v2: improved and extended version, new
references adde
Thin-shell wormholes in (2 + 1) -dimensional F(R) theories
We construct a broad family of thin-shell wormholes with circular symmetry in (2 + 1) -dimensional F(R) theories of gravity, with constant scalar curvature R. We study the stability of the static configurations under perturbations preserving the symmetry. We present examples of charged thin-shell wormholes which are asymptotically anti-de Sitter at both sides of the throat. We show that stable solutions are possible when suitable values of the parameters are taken.Fil: Bejarano, Cecilia Soledad. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Eiroa, Ernesto Fabian. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Figueroa Aguirre, Griselda Verónica. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; Argentin
Pure double-layer bubbles in quadratic F ( R ) gravity
We present a class of spherically symmetric spacetimes corresponding tobubbles separating two regions with constant values of the scalar curvature, orequivalently with two different cosmological constants, in quadratic F(R)theory. The bubbles are obtained by means of the junction formalism, and thematching hypersurface supports in general a thin shell and a gravitationaldouble layer. In particular, we find that pure double layers are possible forappropriate values of the parameters of the model whenever the quadraticcoefficient is negative. This is the first example of a pure double layer in agravitational theory.Fil: Eiroa, Ernesto Fabian. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Figueroa Aguirre, Griselda Verónica. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Senovilla, José M. M.. Universidad del PaÃs Vasco; Españ
Thin-shell wormholes with a generalized Chaplygin gas in Einstein-Born-Infeld theory
We construct spherically symmetric thin-shell wormholes supported by a
generalized Chaplygin gas in Born-Infeld electrodynamics coupled to Einstein
gravity, and we analyze their stability under radial perturbations. For
different values of the Born-Infeld parameter and the charge, we compare the
results with those obtained in a previous work for Maxwell electrodynamics. The
stability region in the parameter space reduces and then disappears as the
value of the Born-Infeld parameter is modified in the sense of a larger
departure from Maxwell theory.Comment: 9 pages, 6 figures; v2: improved versio