arXiv subjects

Griselda Figueroa-Aguirre

Publications and source records attributed to Griselda Figueroa-Aguirre.

18 recordsLinked to original sources

arXiv2026

Spherical thin shells with charge in unimodular gravity

We construct spherically symmetric thin shells in unimodular gravity (UG) and analyze their dynamical stability under radial, symmetry-preserving perturbations. We use the UG junction conditions and adopt non-conservative charged exterior solutions sourced by a radial electric field. As an application, we build charged vacuum bubbles: a Minkowski interior surrounded by a charged thin shell and matched to an exterior UG geometry. The resulting spacetimes are free of event horizons and central singularities, while in de Sitter-like cases a cosmological horizon may exist outside the shell. We compare the stability regions and the matter content with their counterparts in general relativity, finding some differences controlled by the UG non-conservation parameter. This work extends previously published results.

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arXiv2026

Entropy and stability of an extremally charged Einstein-Born-Infeld thin shell

Spacetimes with a thin shell offer a framework where both the dynamical and the thermodynamical stability of the matter comprising the shell can be consistently studied. In the present work, we consider the dynamical and the thermodynamical stability of a spherical thin shell in Einstein gravity coupled to Born-Infeld electrodynamics. For our construction, we adopt the extremally charged solution of the theory, which gives a closed analytic form for the horizon location that allows for a clear derivation of the corresponding physical quantities of interest. Under this scenario, the dynamical stability conditions under radial perturbations are readily obtained in terms of an effective potential. The equilibrium thermodynamics for such a shell is presented. We find that, despite a non-zero pressure at the shell (unlike the extremally charged Reissner-Nordström counterpart), its entropy is solely characterized as a function of the gravitational radius. We propose a physically suitable \emph{ansatz} for the relevant equations of state in order to obtain a closed expression for the entropy density of the shell. We find that the thermodynamical stability conditions reduce to a single inequality related to exchanges of the charge at the shell, which determines the domain where both dynamical and thermodynamical stable configurations exist.

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arXiv2026

Stability of spherical thin-shell wormholes in scalar-tensor theories

In this article, we construct a family of spherically symmetric thin-shell wormholes within scalar-tensor theories of gravity. In the case of wormholes symmetric across the throat, we study the matter content and analyze the stability of the static configurations under radial perturbations. We apply the formalism to a particular example involving Einstein-Maxwell gravity coupled to a conformally invariant scalar field. We show that stable configurations are possible for suitable values of the parameters involved.

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arXiv2025

Charged thin shells in unimodular gravity

In this article, we construct a broad family of spacetimes with spherically symmetric thin shells in unimodular gravity. We present the framework for the analysis of the dynamical stability of the configurations under perturbations preserving the symmetry. In particular, we consider two different scenarios in which the non-conservation of the energy-momentum tensor is allowed; in both the spacetime has a thin shell with charge surrounding vacuum. Our constructions avoid the existence of event horizons and singularities. In both cases, we have obtained stable configurations for suitable values of the parameters. We compare our results with those corresponding to general relativity, finding some differences in the matter content and in the stability regions in the parameter space.

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arXiv2024

Dynamical and thermodynamical stability of a charged thin-shell wormhole

A study of the dynamical and thermodynamical stability of a charged thin-shell wormhole built by gluing two Reissner-Nordström geometries is presented. The charge on the shell is linearly related to the matter content. For the dynamical stability, a concise inequality is obtained, valid for any barotropic equation of state that relates the pressure with the energy density at the throat. A thermodynamical description of the system is introduced, which leads to the temperature and the electric potentials. Adopting a linear equation of state for the pressure and a definite form for the entropy function, the set of equilibrium configurations that are both dynamically and thermodynamically stable is found.

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arXiv2023

Thin-shell wormholes in N-dimensional F(R) gravity

In this work, spherically symmetric thin-shell wormholes with a conformally invariant Maxwell field for $N$-dimensional $F(R)$ gravity and constant scalar curvature $R$ 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.

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arXiv2022

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 solution with spherical symmetry already known in the literature for $N$-dimensional $F(R)$ gravity with a conformally invariant Maxwell field and constant scalar curvature $R$. This solution also includes a generalization of the one corresponding to general relativity as a special case. We introduce the formalism for the construction of a broad family of spherically symmetric thin shells in $F(R)$ theory. We use our generalized solution 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 $N$.

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arXiv2021

Circularly symmetric thin-shell wormholes in F(R) gravity with (2+1)-dimensions

Within the framework of $F(R)$ theories of gravity with (2+1)-dimensions and constant scalar curvature $R$, we construct a family of thin-shell wormholes with circular symmetry and we analyze the stability of the static configurations under radial perturbations. We show an example of asymptotically anti-de Sitter thin-shell wormholes with charge, finding that stable configurations with normal matter are possible for a suitable range of the parameters.

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arXiv2021

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 charged thin-shell wormholes as examples of spacetimes with a negative cosmological constant. We show that stable solutions are possible when suitable values of the parameters are taken.

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arXiv2021

Thin shells in (2+1)-dimensional F(R) gravity

We study thin shells of matter in (2+1)-dimensional F(R) theories of gravity with constant scalar curvature R. We consider a wide class of spacetimes with circular symmetry, in which a thin shell joins an inner region with an outer one. We analyze the stability of the static configurations under radial perturbations. As examples of spacetimes asymptotically anti-de Sitter, we present a charged bubble and a charged thin shell surrounding a non-charged black hole. In both cases, we show that stable solutions can be found for suitable values of the parameters.

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arXiv2020

Thin shells in F(R) gravity with non-constant scalar curvature

We introduce two classes of spherically symmetric spacetimes having a thin shell of matter, in non-quadratic F(R) theories of gravity with non-constant scalar curvature R. In the first, the thin shell joins an inner region with an outer one, while in the second it corresponds to the throat of a wormhole. In both scenarios, we analyze the stability of the static configurations under radial perturbations. As particular examples in spacetimes with a cosmological constant, we present charged thin shells surrounding a non-charged black hole and charged thin-shell wormholes. We show that in both cases stable solutions are possible for suitable values of the parameters.

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arXiv2019

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.

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arXiv2018

Spherical thin shells in F(R) gravity: construction and stability

We present a broad class of spherical thin shells of matter in F(R) gravity. We show that the corresponding junction conditions determine the equation of state between the energy density and the pressure/tension at the surface. We analyze the stability of the static configurations under perturbations preserving the symmetry. We apply the formalism to the construction of charged bubbles and we find that there exist stable static configurations for a suitable set of the parameters of the model.

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arXiv2017

Pure double-layer bubbles in quadratic F(R) gravity

We present a class of spherically symmetric spacetimes corresponding to bubbles separating two regions with constant values of the scalar curvature, or equivalently with two different cosmological constants, in quadratic F(R) theory. The bubbles are obtained by means of the junction formalism, and the matching hypersurface supports in general a thin shell and a gravitational double layer. In particular, we find that pure double layers are possible for appropriate values of the parameters of the model whenever the quadratic coefficient is negative. This is the first example of a pure double layer in a gravitational theory.

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arXiv2016

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.

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arXiv2016

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.

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arXiv2015

Thin-shell wormholes in Einstein-Born-Infeld theory

We construct spherically symmetric thin-shell wormholes with a generalized Chaplygin gas at the throat, in Born-Infeld electrodynamics coupled to Einstein gravity. We analyze their stability under radial perturbations.

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arXiv2012

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.

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