Examinando por Autor "Miskovic, Olivera"
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Ítem Black hole solutions in Chern-Simons AdS supergravity(Springer Verlag, 2014-08) Giribet, Gaston; Merino, Nelson; Miskovic, Olivera; Zanelli, JorgeWe study charged AdS black hole solutions in five-dimensional Chern-Simons supergravity. The minimal supergroup containing such AdS5 × U(1) configurations is the superunitary group SU(2, 2|N ). For this model, we find analytic black hole solutions that asymptote to locally AdS5 spacetime at the boundary. A solution can carry U(1) charge provided the spacetime torsion is non-vanishing. Thus, we analyze the most general config uration consistent with the local AdS5 isometries in Riemann-Cartan space. The coupling of torsion in the action resembles that of the universal axion of string theory, and it is ulti mately due to this field that the theory acquires propagating degrees of freedom. Through a careful analysis of the canonical structure the local degrees of freedom of the theory are identified in the static symmetric sector of phase space.Ítem Conformal mass in Einstein-Gauss-Bonnet AdS gravity(American Physical Society, 2015-06) Jatkar, Dileep P.; Kofinas, Georgios; Miskovic, Olivera; Olea, RodrigoIn this paper, we show that the physical information given by conserved charges for asymptotically AdS spacetimes in Einstein-Gauss-Bonnet AdS gravity is encoded in the electric part of the Weyl tensor. This result generalizes the conformal mass definition by Ashtekar-Magnon-Das (AMD) to a gravity theory with a Gauss-Bonnet term. This proof makes use of the Noether charges obtained from an action renormalized by the addition of counterterms which depend on the extrinsic curvature (Kounterterms). If the asymptotic fall-off behavior of the Weyl tensor is same as the one considered in the AMD method, then the Kounterterm charges and the AMD charges agree in any dimension. © 2015 American Physical Society.Ítem Energy of anti-de Sitter black holes in odd-dimensional quadratic curvature gravity(American Physical Society, 2022-09-15) Miskovic, Olivera; Olea, Rodrigo; Parra Cisterna, YoelWe provide new formulas for the energy of black hole solutions in the anti-de Sitter (AdS) sector of a generic gravity theory with curvature-squared terms. This is achieved by the addition of counterterms of the extrinsic type (Kounterterms) which produces a finite variation of the total action. The procedure is compatible with the boundary conditions in asymptotically AdS spaces within the framework of quadratic curvature gravity (QCG) theory. As a consequence, without resorting to background-substraction, or linearized methods, the conserved charges correctly reproduce the energy of static black holes in QCG. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.Ítem First-order Lagrangian of Lovelock gravity and applications(Universidad Andrés Bello, 2022) Guilleminot Arellano, Pablo; Olea, Rodrigo; Merino, Nelson; Faraggi, Alberto; Miskovic, Olivera; Aros, Rodrigo; Corral, Cristóbal; Facultad de Ciencias ExactasEn este trabajo, se analizan, analíticamente, aspectos de evolución espacial en gravedad de Lovelock. Se muestra que la adición de términos de Myers a la acción elimina las derivadas de segundo orden respecto a la variable de evolución. Así, la conexión entre el problema de Dirichlet y Lagrangianos de primer orden es establecida. Luego, se exhibe como la transformada de Legendre de este último permite calcular directamente el Hamiltoniano del sistema para la misma variable de evolución. Con estos resultados, se analiza el comportamiento de cáscaras delgadas con masa en el contexto de gravedad de Lovelock. Para esto, se trabaja el principio variacional escrito en un set adaptado de coordenadas válido cerca de la cáscara. Se concluye que la cantidad que es discontínua en la cáscara es el momentum canónico. Finalmente se obtienen algunas expresiones explicitas para configuraciones con simetría esférica.Ítem Magnetic mass in 4D AdS gravity(AMER PHYSICAL SOC, 2016-04) Araneda, René; Aros, Rodrigo; Miskovic, Olivera; Olea, RodrigoWe provide a fully covariant expression for the diffeomorphic charge in four-dimensional anti-de Sitter gravity, when the Gauss-Bonnet and Pontryagin terms are added to the action. The couplings of these topological invariants are such that the Weyl tensor and its dual appear in the on-shell variation of the action and such that the action is stationary for asymptotic (anti-)self-dual solutions in the Weyl tensor. In analogy with Euclidean electromagnetism, whenever the self-duality condition is global, both the action and the total charge are identically vanishing. Therefore, for such configurations, the magnetic mass equals the Ashtekhar-Magnon-Das definition.Ítem Mass in Lovelock unique vacuum gravity theories(American Physical Society, 2019-09) Arenas Henriquez, Gabriel; Mann, Robert B.; Miskovic, Olivera; Olea, RodrigoWe derive an expression for conserved charges in Lovelock anti-de Sitter gravity for solutions having k-fold degenerate vacua, making manifest a link between the degeneracy of a given vacuum and the nonlinearity of the energy formula. We show for a black hole solution to the field equations on a branch of multiplicity k that its mass comes from an expression that contains the product of k Weyl tensors. We prove that all divergent contributions of the type (Weyl)q, with 1≤q[removed]1. Our results provide insight on the holographic properties of degenerate Lovelock theories.Ítem Renormalized AdS action and critical gravity(Springer Verlag, 2014-08) Miskovic, Olivera; Tsoukalas, Minas; Olea, RodrigoIt is shown that the renormalized action for AdS gravity in even spacetime dimensions is equivalent “on shell” to a polynomial of the Weyl tensor, whose first non vanishing term is proportional to W eyl2 . Remarkably enough, the coupling of this last term coincides with the one that appears in Critical Gravity.Ítem Vacuum energy in asymptotically flat 2 + 1 gravity(Elsevier B.V., 2017-04) Miskovic, Olivera; Olea, Rodrigo; Roy, DebrajWe compute the vacuum energy of three-dimensional asymptotically flat space based on a Chern–Simons formulation for the Poincaré group. The equivalent action is nothing but the Einstein–Hilbert term in the bulk plus half of the Gibbons–Hawking term at the boundary. The derivation is based on the evaluation of the Noether charges in the vacuum. We obtain that the vacuum energy of this space has the same value as the one of the asymptotically flat limit of three-dimensional anti-de Sitter space. © 2017 The Author(s)