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Leonardo Sanhueza

Publications and source records attributed to Leonardo Sanhueza.

7 recordsLinked to original sources

Extrinsic Renormalization of New Massive Gravity

The renormalization of asymptotically AdS spacetimes in New Massive Gravity is studied using boundary terms constructed with the extrinsic curvature. For generic values of the theory couplings, a single extrinsic boundary term produces a consistent holographic description, as the variation of the total action is finite and expressible in terms of the holographic source. This prescription applies to constant-curvature geometries and non-Einstein solutions with Brown-Henneaux asymptotic conditions. A suitable asymptotic expansion shows the agreement of the resulting holographic stress tensor with the one obtained from the auxiliary-field formulation. At the degenerate point, where the two maximally symmetric vacua coalesce, the Fefferman-Graham expansion admits an additional mode associated with relaxed AdS boundary conditions. A quadratic extrinsic counterterm removes the new divergences and leads naturally to a holographic picture with two independent sources. The corresponding responses obey a modified holographic Ward identity and determine finite conserved charges. Finally, the proper use of the Noether-Wald formalism reproduces the correct charges of the BTZ black hole, non-Einstein AdS waves, and the rotating hairy black hole.

hep-th↗

Gravitational Memory Beyond Null Infinity through Finite-Distance Carrollian Screens

We investigate gravitational memory beyond null infinity by studying finite-distance null hypersurfaces endowed with Carrollian geometry. We show that the intrinsic degenerate geometry, optical data, and null Brown--York tensor of a finite null screen define a quasilocal Carrollian dissipative system, providing a natural framework to characterize the residual geometric response after the passage of radiation. To make this construction explicit and compare it with the standard asymptotic description, we use Robinson--Trautman spacetimes as an exactly solvable radiative setting. For asymptotically flat Robinson--Trautman geometries, we transform the solution to Bondi gauge and extract the asymptotic data directly in terms of the Robinson--Trautman field. In the linearized sector, the Bondi shear is purely electric and produces the standard displacement-memory effect associated with the relaxation toward the final Schwarzschild geometry. We show that the leading large-radius tracefree component of the finite-screen memory reduces to the Bondi displacement memory, while finite-distance corrections retain additional focusing, embedding dependence, angular drift, Coulombic data, and near-zone information. Thus, Bondi memory emerges as the universal asymptotic projection of a broader quasilocal Carrollian response. Late-time screens approaching the final Schwarzschild horizon exhibit exponentially decaying non-isotropic Carrollian data, leaving only the isotropic null Brown--York stress. As a by-product, we construct the Robinson--Trautman solution with nonzero cosmological constant to second order in the radiative amplitude and use the holographic dictionary to study the associated energy fluxes and find that the resulting charge does not obey a universal monotonicity property.

hep-th↗

Self-gravitating baryonic tubes supported by $π$- and $ω$-mesons and its flat limit

In this paper, we construct self-gravitating topological solitons in the $SU(N)$ Einstein non-linear sigma model coupled to $ω$-vector mesons in four space-time dimensions. These solutions represent tube-like configurations free of curvature singularities, carrying a non-vanishing topological charge that is identified as the baryon number. We show that by employing the maximal embedding Ansatz of $SU(2)$ into $SU(N)$ in the exponential representation, these tubes can be constructed for an arbitrary number of flavors, $N$, with the topological charge scaling proportionally to this number. The flat-space limit of the solutions, corresponding to an array of baryonic tubes within a finite volume, is analyzed in detail. Remarkably, while the total energy of the solitons at a finite volume is an increasing function of $N$, the binding energy decreases as the number of flavors increases. This analysis reaffirms that the inclusion of more than two flavors to the model systematically improves the physical predictions.

hep-th↗

Inhomogeneous metrics on complex bundles in Lovelock gravity

We consider Lovelock gravity in arbitrary, even dimensions. We find a large class of new gravitational instantons by considering extended nontrivial circle bundles over Kähler manifolds. Concretely, we generalize the Page-Pope metric in the presence of higher-curvature corrections of the Lovelock class. A subset of these spaces admits analytic continuation into the Lorentzian sector, producing new stationary solutions in Lovelock gravity. The geometries are fully determined by a single algebraic equation. We also obtain necessary and sufficient conditions for Lovelock-constant Kähler manifolds to exist in Lovelock gravity. Finally, we find a wide class of Lovelock-Maxwell solutions beyond staticity, allowing us to obtain the electrovacuum extension of these instantons.

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Axial anomaly in nonlinear conformal electrodynamics

We study the axial anomaly of Dirac spinors on gravitational instanton backgrounds in the context of nonlinear electrodynamics. In order to do so, we consider Einstein gravity minimally coupled to a recently proposed conformal electrodynamics that enjoys duality transformation invariance. These symmetries allow us to generalize the Eguchi-Hanson configuration while preserving its geometry. We then compute the Dirac index of the nonlinearly charged Eguchi-Hanson and Taub-NUT configurations. We find that there is an excess of positive chiral Dirac fermions over the negative ones which triggers the anomaly.

hep-th↗

Quasitopological electromagnetism: Reissner-Nordström black strings in Einstein and Lovelock gravities

In this work, we provide consistent compactifications of Einstein-Maxwell and Einstein-Maxwell-Lovelock theories on direct product spacetimes of the form $\mathcal{M}_D=\mathcal{M}_d\times\mathcal{K}^{p}$, where $\mathcal{K}^p$ is a Euclidean internal manifold of constant curvature. For these compactifications to take place, it is required the distribution of a precise flux of $p$-forms over the internal manifold. The dynamic of the $p$-forms are demanded to be controlled by two types of interaction. First, by specific couplings with the curvature tensor and, second, by a suitable interaction with the electromagnetic field of the $d$-dimensional brane, the latter being dictated by a modification of the recently proposed theory of Quasitopological Electromagnetism. The field equations of the corresponding compactified theories, which are of second order, are solved and general homogenous charged black p-branes are constructed. We explicitly provide homogenous Reissner-Nordström black strings and black p-branes in Einstein-Maxwell theory and homogenous charged Boulware-Deser black p-branes for quadratic and cubic Maxwell-Lovelock gravities.

gr-qc↗

Hairy Taub-NUT/Bolt-AdS solutions in Horndeski theory

We present different Taub-NUT/Bolt-anti de Sitter (AdS) solutions in a shift-symmetric sector of Horndeski theory of gravity possessing nonminimal kinetic coupling of scalar fields to the Einstein tensor. In four dimensions, we find locally and asymptotically locally AdS solutions possessing nontrivial scalar field. In higher dimensions, analytical Taub-NUT/Bolt-AdS p-branes and solitons are obtained, supported by the existence of p Horndeski scalar fields with axionic profile. The thermodynamical properties are studied through Euclidean methods and it is found that the first law of thermodynamics is satisfied. Moreover, constraints on the parameter space of Horndeski gravity and NUT charge are obtained by demanding positivity of the mass, entropy, and specific heat of the p-branes and soliton. We briefly comment on future applications in holography.

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