Ángel Murcia

Centro de Física Teórica y Matemáticas | CFTMAT · Institute for Theoretical Physics

We investigate the differential geometry and topology of four-dimensional Lorentzian manifolds (M, g) equipped with a real Killing spinor \(\varepsilon \), where \(\varepsilon \) is defined as a section of a bundle of irreducible real Clifford modules satisfying the Killing spinor equation with nonzero real constant. Such triples \((M,g,\varepsilon...

We investigate the differential geometry and topology of four-dimensional Lorentzian manifolds $(M,g)$ equipped with a real Killing spinor $\varepsilon$, where $\varepsilon$ is defined as a section of a bundle of irreducible real Clifford modules satisfying the Killing spinor equation with non-zero real constant. Such triples $(M,g,\varepsilon)$ ar...

R\'enyi entropies, $S_n$, admit a natural generalization in the presence of global symmetries. These "charged R\'enyi entropies" are functions of the chemical potential $\mu$ conjugate to the charge contained in the entangling region and reduce to the usual notions as $\mu\rightarrow 0$. For $n=1$, this provides a notion of charged entanglement ent...

We investigate the differential geometry and topology of globally hyperbolic four-manifolds (M, g) admitting a parallel real spinor ε. Using the theory of parabolic pairs recently introduced in [22], we first formulate the parallelicity condition of ε on M as a system of partial differential equations, the parallel spinor flow equations, for a fami...

We carry out an extensive study of the holographic aspects of any-dimensional higher-derivative Einstein-Maxwell theories in a fully analytic and non-perturbative fashion. We achieve this by introducing the $d$-dimensional version of Electromagnetic Quasitopological gravities: higher-derivative theories of gravity and electromagnetism that propagat...

We study nonminimal extensions of Einstein-Maxwell theory with exact electromagnetic duality invariance. Any such theory involves an infinite tower of higher-derivative terms whose computation usually represents a challenging problem. Despite that, we manage to obtain a closed form of the action for all the theories with a quadratic dependence on t...

The three-dimensional parallel spinor flow is the evolution flow defined by a parallel spinor on a globally hyperbolic Lorentzian four-manifold. We prove that, despite the fact that Lorentzian metrics admitting parallel spinors are not necessarily Ricci flat, the parallel spinor flow preserves the vacuum momentum and Hamiltonian constraints and the...

A bstract We investigate higher-derivative extensions of Einstein-Maxwell theory that are invariant under electromagnetic duality rotations, allowing for non-minimal couplings between gravity and the gauge field. Working in a derivative expansion of the action, we characterize the Lagrangians giving rise to duality-invariant theories up to the eigh...

We introduce the concept of $\varepsilon\,$-contact metric structures on oriented (pseudo-)Riemannian three-manifolds, which encompasses the usual Riemannian contact metric, Lorentzian contact metric and para-contact metric structures, but which also allows the possibility for the Reeb vector field to be null. We investigate in more detail this lat...

We study dyonic black hole solutions in the simplest nonminimal extension of Einstein-Maxwell theory that preserves electromagnetic duality. Any such theory involves an infinite tower of higher-derivative terms whose computation and summation usually represents an inaccessible problem. However, we show that upon assumption of a static and spherical...

A bstract We review and extend results on higher-curvature corrections to different configurations describing a superposition of heterotic strings, KK monopoles, solitonic 5-branes and momentum waves. Depending on which sources are present, the low-energy fields describe a black hole, a soliton or a naked singularity. We show that this property is...

We investigate higher-derivative extensions of Einstein-Maxwell theory that are invariant under electromagnetic duality rotations, allowing for non-minimal couplings between gravity and the gauge field. Working in a derivative expansion of the action, we characterize the Lagrangians giving rise to duality-invariant theories up to the eight-derivati...

We describe a non-minimal higher-derivative extension of Einstein-Maxwell theory in which electrically-charged black holes and point charges have globally regular gravitational and electromagnetic fields. We provide an exact static, spherically symmetric solution of this theory that reduces to the Reissner-Nordström one at weak coupling, but in whi...

We review and extend results on higher-curvature corrections to different configurations describing a superposition of heterotic strings, KK monopoles, solitonic 5-branes and momentum waves. Depending on which sources are present, the low-energy fields describe a black hole, a soliton or a naked singularity. We show that this property is unaltered...

We investigate four-dimensional Heterotic solitons, defined as a particular class of solutions of the equations of motion of Heterotic supergravity on a four-manifold $M$. Heterotic solitons depend on a parameter $\kappa$ and consist of a Riemannian metric $g$, a metric connection with skew torsion $H$ on $TM$ and a closed one-form $\varphi$ on $M$...

We investigate the differential geometry and topology of globally hyperbolic four-manifolds $(M,g)$ admitting a parallel real spinor $\varepsilon$. Using the theory of parabolic pairs recently introduced in arXiv:1911.08658 , we first formulate the parallelicity condition of $\varepsilon$ on $M$ as a system of partial differential equations, the pa...

A bstract We identify a set of higher-derivative extensions of Einstein-Maxwell theory that allow for spherically symmetric charged solutions characterized by a single metric function f ( r ) = −g tt = 1/ g rr . These theories are a non-minimally coupled version of the recently constructed Generalized Quasitopological gravities and they satisfy a n...

We introduce the notion of εη-Einstein ε-contact metric three-manifold, which includes as particular cases η-Einstein Riemannian and Lorentzian (para) contact metric three-manifolds, but which in addition allows for the Reeb vector field to be null. We prove that the product of an εη-Einstein Lorentzian ε-contact metric three-manifold with an εη-Ei...

We identify a set of higher-derivative extensions of Einstein-Maxwell theory that allow for spherically symmetric charged solutions characterized by a single metric function $f(r)=-g_{tt}=1/g_{rr}$. These theories are a non-minimally coupled version of the recently constructed Generalized Quasitopological gravities and they satisfy a number of prop...

We describe a non-minimal higher-derivative extension of Einstein-Maxwell theory in which electrically-charged black holes and point charges have globally regular gravitational and electromagnetic fields. We provide an exact static spherically symmetric solution of this theory that reduces to the Reissner-Nordstr\"om one at weak coupling, but in wh...

We introduce the notion of $\varepsilon\eta\,$-Einstein $\varepsilon\,$-contact metric three-manifold, which includes as particular cases $\eta\,$-Einstein Riemannian and Lorentzian (para) contact metric three-manifolds, but which in addition allows for the Reeb vector field to be null. We prove that the product of an $\varepsilon\eta\,$-Einstein L...

A bstract Generalized quasi-topological gravities (GQTGs) are higher-curvature extensions of Einstein gravity characterized by the existence of non-hairy generalizations of the Schwarzschild black hole which satisfy g tt g rr = –1 , as well as for having second-order linearized equations around maximally symmetric backgrounds. In this paper we prov...

Generalized quasi-topological gravities (GQTGs) are higher-curvature extensions of Einstein gravity characterized by the existence of non-hairy generalizations of the Schwarzschild black hole which satisfy $g_{tt}g_{rr}=-1$, as well as for having second-order linearized equations around maximally symmetric backgrounds. In this paper we provide stro...