Examinando por Autor "Olea, Rodrigo"
Mostrando 1 - 20 de 23
Resultados por página
Opciones de ordenación
Ítem CFT correlators from shape deformations in Cubic Curvature Gravity(Springer Science and Business Media Deutschland GmbH, 2022-11) Anastasiou, Giorgos; Araya, Ignacio J.; Argandoña, Andrés; Olea, RodrigoWe find a covariant expression for the universal part of the holographic entanglement entropy which is valid for CFTs dual to generic higher curvature gravities in up to five bulk dimensions. We use this functional to compute universal coefficients of stress-tensor correlators in three-dimensional CFTs dual to Cubic Curvature Gravity. Using gauge/gravity duality, we work out an expression for the entanglement entropy of deformed entangling regions and read the coefficients from the power expansion of the entropy in the deformation parameter. In particular, we obtain the t4 coefficient of the 3-point function and exhibit a difference between the results obtained using the entanglement entropy functional for minimal and non-minimal splittings. We compare the obtained expressions for t4 derived considering both splittings with results obtained through other holographic methods which are splitting-independent. We find agreement with the result obtained from the non-minimal splitting, whereas the result derived from the minimal splitting is inconsistent and it is therefore ruled out. © 2022, The Author(s).Ítem Chern-Simons action and the Carrollian Cotton tensors(Springer Science and Business Media Deutschland GmbH Original language, 2023-12) Mišković, Olivera; Olea, Rodrigo; Petropoulos, P. Marios; Rivera-Betancour, David; Siampos, KonstantinosIn three-dimensional pseudo-Riemannian manifolds, the Cotton tensor arises as the variation of the gravitational Chern-Simons action with respect to the metric. It is Weyl-covariant, symmetric, traceless and covariantly conserved. Performing a reduction of the Cotton tensor with respect to Carrollian diffeomorphisms in a suitable frame, one discloses four sets of Cotton Carrollian relatives, which are conformal and obey Carrollian conservation equations. Each set of Carrollian Cotton tensors is alternatively obtained as the variation of a distinct Carroll-Chern-Simons action with respect to the degenerate metric and the clock form of a strong Carroll structure. The four Carroll-Chern-Simons actions emerge in the Carrollian reduction of the original Chern-Simons ascendant. They inherit its anomalous behaviour under diffeomorphisms and Weyl transformations.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 Conformal Renormalization of topological black holes in AdS6(Springer Science and Business Media Deutschland GmbH, 2023-11) Anastasiou, Giorgos; Araya, Ignacio J.; Corral, Cristóbal; Olea, RodrigoWe present a streamlined proof that any Einstein-AdS space is a solution of the Lu, Pang and Pope conformal gravity theory in six dimensions. The reduction of conformal gravity into Einstein theory manifestly shows that the action of the latter can be written as the Einstein-Hilbert term plus the Euler topological density and an additional contribution that depends on the Laplacian of the bulk Weyl tensor squared. The prescription for obtaining this form of the action by embedding the Einstein theory into a Weyl-invariant purely metric theory, was dubbed Conformal Renormalization and its resulting action was shown to be equivalent to the one obtained by holographic renormalization. As a non-trivial application of the method, we compute the Noether-Wald charges and thermodynamic quantities for topological black hole solutions with generic transverse section in Einstein-AdS6 theory.Ítem Constant curvature black holes in Einstein-AdS gravity: Conserved quantities(American Physical Society, 2017-06) Guilleminot, Pablo; Olea, Rodrigo; Petrov, Alexander N.We study physical properties of constant curvature black holes in Einstein-anti-de Sitter (AdS) gravity. These objects, which are locally AdS throughout the space, are constructed from identifications of global AdS spacetime, in a similar fashion as the Banados-Teitelboim-Zanelli black hole in three dimensions. We find that, in dimensions equal to or greater than 4, constant curvature black holes have zero mass and angular momentum. Only in odd dimensions are we able to associate a nonvanishing conserved quantity to these solutions, which corresponds to the vacuum (Casimir) energy of the spacetime. © 2017 American Physical Society.Ítem Einstein-Gauss-Bonnet theory of gravity: The Gauss-Bonnet-Katz boundary term(American Physical Society, 2018-05) Deruelle, Nathalie; Merino, Nelson; Olea, RodrigoWe propose a boundary term to the Einstein-Gauss-Bonnet action for gravity, which uses the Chern-Weil theorem plus a dimensional continuation process, such that the extremization of the full action yields the equations of motion when Dirichlet boundary conditions are imposed. When translated into tensorial language, this boundary term is the generalization to this theory of the Katz boundary term and vector for general relativity. The boundary term constructed in this paper allows to deal with a general background and is not equivalent to the Gibbons-Hawking-Myers boundary term. However, we show that they coincide if one replaces the background of the Katz procedure by a product manifold. As a first application we show that this Einstein Gauss-Bonnet Katz action yields, without any extra ingredients, the expected mass of the Boulware-Deser black hole. © 2018 American Physical Society.Ítem Energy functionals from Conformal Gravity(Springer Science and Business Media Deutschland GmbH, 2022-10) Anastasiou, Giorgos; Araya, Ignacio J.; Olea, RodrigoWe provide a new derivation of the Hawking mass and Willmore energy functionals for asymptotically AdS spacetimes, by embedding Einstein-AdS gravity in Conformal Gravity. By construction, the evaluation of the four-dimensional Conformal Gravity action in a manifold with a conical defect produces a codimension-2 conformal invariant functional LΣ. The energy functionals are then particular cases of LΣ for Einstein-AdS and pure AdS ambient spaces, respectively. The bulk action is finite for AdS asymptotics and both Hawking mass and Willmore energy are finite as well. The result suggests a generic relation between conformal invariance and renormalization, where the codimension-2 properties are inherited from the bulk gravity action. © 2022, The Author(s).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 From conformal to Einstein gravity(Elsevier, 2016-10) Anastasiou, Giorgos; Olea, RodrigoWe provide a simple derivation of the equivalence between Einstein and conformal gravity (CG) with Neumann boundary conditions given by Maldacena. As Einstein spacetimes are Bach flat, a generic solution to CG would contain both Einstein and non-Einstein parts. Using this decomposition of the spacetime curvature in the Weyl tensor makes manifest the equivalence between the two theories, both at the level of the action and the variation of it. As a consequence, we show that the on-shell action for critical gravity in four dimensions is given uniquely in terms of the Bach tensor.Ítem Holographic renormalization of Horndeski gravity(Springer Science and Business Media Deutschland GmbH, 2024-04-05) Cáceres, Nicolás; Corral, Cristóbal; Díaz, Felipe; Olea, RodrigoWe study the renormalization of a particular sector of Horndeski theory. In particular, we focus on the nonminimal coupling of a scalar field to the Gauss-Bonnet term and its kinetic coupling to the Einstein tensor. Adopting a power expansion on the scalar function that couples the Gauss-Bonnet term, we find specific conditions on their coefficients such that the action and charges are finite. To accomplish the latter, we add a finite set of intrinsic boundary terms. The contribution of the nonminimal coupling generates an effective scalar mass, allowing us to recover a modified Breitenlohner-Freedman bound. Furthermore, we compute the holographic 1-point functions and Ward identities associated with the scalar field and the metric. We constrain the parameter space of the theory by taking into account the preservation of scaling symmetry at the boundary.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 Renormalization of entanglement entropy from topological terms(American Physical Society, 2018-05) Anastasiou, Giorgos; Araya, Ignacio J.; Olea, RodrigoWe propose a renormalization scheme for entanglement entropy of three-dimensional CFTs with a four-dimensional asymptotically AdS gravity dual in the context of the gauge/gravity correspondence. The procedure consists in adding the Chern form as a boundary term to the area functional of the Ryu-Takayanagi minimal surface. We provide an explicit prescription for the renormalized entanglement entropy, which is derived via the replica trick. This is achieved by considering a Euclidean gravitational action renormalized by the addition of the Chern form at the spacetime boundary, evaluated in the conically-singular replica manifold. We show that the addition of this boundary term cancels the divergent part of the entanglement entropy, recovering the results obtained by Taylor and Woodhead. We comment on how this prescription for renormalizing the entanglement entropy is in line with the general program of topological renormalization in asymptotically AdS gravity. © 2018 authors. Published by the American Physical Society.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 Renormalized AdS gravity and holographic entanglement entropy of even-dimensional CFTs(Springer Verlag, 2019-10) Anastasiou, Giorgos; Araya, Ignacio J.; Güijosa, Alberto; Olea, RodrigoWe derive a general formula for renormalized entanglement entropy in even- dimensional CFTs holographically dual to Einstein gravity in one dimension higher. In order to renormalize, we adapt the Kounterterm method to asymptotically locally AdS manifolds with conical singularities. On the gravity side, the computation considers extrin- sic counterterms and the use of the replica trick à la Lewkowycz-Maldacena. The boundary counterterm Bd is shown to satisfy a key property, in direct analogy to the Euler density: when evaluated on a conically singular manifold, it decomposes into a regular part plus a codimension-2 version of itself located at the conical singularity. The renormalized entropy thus obtained is shown to correspond to the universal part of the holographic entangle- ment entropy, which for spherical entangling surfaces is proportional to the central charge a that is the subject of the a-theorem. We also review and elucidate various aspects of the Kounterterm approach, including in particular its full compatibility with the Dirichlet condition for the metric at the conformal boundary, that is of standard use in holography. © 2019, The Author(s).Ítem Renormalized holographic entanglement entropy for quadratic curvature gravity(American Physical Society, 2021-10) Giorgos, Anastasiou; Araya, , Ignacio J; Moreno, , Javier; Olea, Rodrigo; Rivera-Betancour, DavidWe derive a covariant expression for the renormalized holographic entanglement entropy for conformal field theories (CFTs) dual to quadratic curvature gravity in arbitrary dimensions. This expression is written as the sum of the bare entanglement entropy functional obtained using standard conical defect techniques, and a counterterm defined at the boundary of the extremal surface of the functional. The latter corresponds to the cod-2 self-replicating part of the extrinsic counterterms when evaluated on the replica orbifold. This renormalization method isolates the universal terms of the holographic entanglement entropy functional. We use it to compute the standard -function candidate for CFTs of arbitrary dimension, and the type-B anomaly coefficient for four-dimensional CFTs. © 2021 Published by the American Physical SocietyÍtem Renormalized holographic entanglement entropy for quadratic curvature gravity(American Physical Society, 2021-10) Anastasiou, Giorgos; Araya, Ignacio J.; Moreno, Javier; Olea, Rodrigo; Rivera Betancour, DavidWe derive a covariant expression for the renormalized holographic entanglement entropy for conformal field theories (CFTs) dual to quadratic curvature gravity in arbitrary dimensions. This expression is written as the sum of the bare entanglement entropy functional obtained using standard conical defect techniques, and a counterterm defined at the boundary of the extremal surface of the functional. The latter corresponds to the cod-2 self-replicating part of the extrinsic counterterms when evaluated on the replica orbifold. This renormalization method isolates the universal terms of the holographic entanglement entropy functional. We use it to compute the standard -function candidate for CFTs of arbitrary dimension, and the type-B anomaly coefficient for four-dimensional CFTs. © 2021 Published by the American Physical SocietyÍtem Self-dual gravitational instantons in conformal gravity: Conserved charges and thermodynamics(American Physical Society, 2021-09) Corral, Cristóbal; Giribet, Gastón; Olea, RodrigoWe study non-Einstein Bach-flat gravitational instanton solutions that can be regarded as the generalization of the Taub-NUT/bolt and Eguchi-Hanson solutions of Einstein gravity to conformal gravity. These solutions include non-Einstein spaces which are either asymptotically locally flat spacetimes or asymptotically locally anti-de Sitter (AlAdS). Nevertheless, solutions with different asymptotic conditions exist: we find geometries that present a weakened AlAdS asymptotia, exhibiting the typical low decaying mode of conformal gravity. This permits us to identify the simple Neumann boundary condition that, as it happens in the asymptotically AdS sector, selects the Einstein solution out of the solutions of conformal gravity. All the geometries present nonvanishing Hirzebruch signature and Euler characteristic, being single-centered instantons. We compute the topological charges as well as the Noether charges of the Taub-NUT/bolt and Eguchi-Hanson spacetimes, which happen to be finite. This enables us to study the thermodynamic properties of these geometries. © 2021 authors. Published by the American Physical Society.Ítem Thin shell dynamics in Lovelock gravity(Institute for Ionics, 2022-11) Guilleminot, Pablo; Merino, Nelson; Olea, RodrigoWe study matching conditions for a spherically symmetric thin shell in Lovelock gravity which can be read off from the variation of the corresponding first-order action. In point of fact, the addition of Myers’ boundary terms to the gravitational action eliminates the dependence on the acceleration in this functional and such that the canonical momentum appears in the surface term in the variation of the total action. This procedure leads to junction conditions given by the discontinuity of the canonical momentum defined for an evolution normal to the boundary.In particular, we correct existing results in the literature for the thin shell collapse in generic Lovelock theories, which were mistakenly drawn from an inaccurate analysis of the total derivative terms in the system. © 2022, The Author(s).