1.5k citations · 3.2k across the 52 of their papers we have counts for
53 papers
Dark-to-black super-accretion as a spin-imprinting mechanism for supermassive Kerr black holes
Saeed Fakhry, Nicolas Sanchis-Gual, Jorge Castelo Mourelle +2
The existence of supermassive black holes with masses and large dimensionless spins at high redshift remains a challenge to our understand…
Dark-to-black super accretion as a mechanism for early supermassive black hole growth
Nicolas Sanchis-Gual, Juan Barranco, Juan Carlos Degollado +1
The discovery of supermassive black holes with masses at redshifts challenges conventional formation scenarios based on baryonic accretion and…
Hayward Boson Stars
Sebastian S. Chicaiza-Medina, Juan Carlos Degollado
We examined the Einstein-Klein-Gordon system coupled to a nonlinear electrodynamics framework that asymptotically supports a Hayward spacetime. We explored the solution space of a…
Slowly Rotating Boson Stars
Jorge F. M. Delgado, Juan Carlos Degollado, Luis E. Martínez +1
We present solutions to the Einstein-Klein Gordon system representing boson stars in the slow rotation approximation. By considering slow rotation we are able to reduce the number…
Dynamical transition to spontaneous scalarization in neutron stars: The massive scalar field scenario
Juan Carlos Degollado, Néstor Ortiz, Marcelo Salgado
We analyze numerically the dynamical transition to spontaneous scalarization in neutron stars in the framework of a scalar-tensor theory of gravity where the scalar field is free b…
Shadow of a collapsing star in a regular spacetime
Daniel Nunez, Juan Carlos Degollado
We describe the dynamical formation of the shadow of a collapsing star in a Hayward spacetime in terms of an observer far away from the center and a free falling observer. By solvi…
Born-Infeld boson stars
Víctor Jaramillo, Daniel Martínez-Carbajal, Juan Carlos Degollado +1
We study the Einstein-Klein-Gordon system coupled to the Born-Infeld electrodynamics. We explore the solution space of a static spherically symmetric, complex scalar field minimall…
Boson stars and their relatives in semiclassical gravity
Miguel Alcubierre, Juan Barranco, Argelia Bernal +5
We construct boson star configurations in quantum field theory using the semiclassical gravity approximation. Restricting our attention to the static case, we show that the semicla…
Self-interacting scalar field distributions around Schwarzschild black holes
Alejandro Aguilar-Nieto, Víctor Jaramillo, Juan Barranco +3
Long-lived configurations of massive scalar fields around black holes may form if the coupling between the mass of the scalar field and the mass of the black hole is very small. In…
Determination of the angular momentum of the Kerr black hole from equatorial geodesic motion
Laura O. Villegas, Eduardo Ramirez-Codiz, Víctor Jaramillo +4
We present a method to determine the angular momentum of a black hole, based on observations of the trajectories of the bodies in the Kerr space-time. We use the Hamilton equations…
Head-on collisions of -boson stars
Víctor Jaramillo, Nicolas Sanchis-Gual, Juan Barranco +5
Fully non-linear numerical evolutions of the Einstein-(multi)--Klein-Gordon equations are performed to study head-on collisions of -boson stars. Despite being spherically sym…
On the role of magnetic fields into the dynamics and gravitational wave emission of binary neutron stars
Mariana Lira, Juan Carlos Degollado, Claudia Moreno +1
Modelling as a dipole the magnetic interaction of a binary system of neutron stars, we are able to include the magnetic effects in the Newtonian and in the inspiral dynamics of the…
Extreme -boson stars
Miguel Alcubierre, Juan Barranco, Argelia Bernal +6
A new class of complex scalar field objects, which generalize the well known boson stars, was recently found as solutions to the Einstein-Klein-Gordon system. The generalization co…
A stabilization mechanism for excited fermion-boson stars
Fabrizio Di Giovanni, Saeed Fakhry, Nicolas Sanchis-Gual +2
We study numerically the nonlinear stability of {\it excited} fermion-boson stars in spherical symmetry. Such compound hypothetical stars, composed by fermions and bosons, are grav…
Gravitational and electromagnetic perturbations of a charged black hole in a general gauge condition
Claudia Moreno, Juan Carlos Degollado, Darío Núñez +1
We derive a set of coupled equations for the gravitational and electromagnetic perturbation in the Reissner-Nordström geometry using the Newman Penrose formalism. We show that the…
On the linear stability of -boson stars with respect to radial perturbations
Miguel Alcubierre, Juan Barranco, Argelia Bernal +5
In previous work we constructed new boson star solutions consisting of a family of massive complex scalar fields minimally coupled to gravity in which the individual fields have an…
Stability study of a model for the Klein-Gordon equation in Kerr space-time II
Horst Reinhard Beyer, Miguel Alcubierre, Miguel Megevand
The present paper is a follow-up of our previous paper that derives a slightly simplified model equation for the Klein-Gordon equation, describing the propagation of a scalar field…
Gravitational waves from binary black hole mergers surrounded by scalar field clouds: Numerical simulations and observational implications
Sunil Choudhary, Nicolas Sanchis-Gual, Anshu Gupta +3
We show how gravitational-wave observations of binary black hole (BBH) mergers can constrain the physical characteristics of a scalar field cloud parameterized by mass an…
On the formation of "supermassive" neutron stars and dynamical transition to spontaneous scalarization
Juan Carlos Degollado, Marcelo Salgado, Miguel Alcubierre
It is well known that neutron stars can undergo a phase transition under a certain class of Scalar Tensor Theories of gravity (STT's) where a new order parameter, the {\it scalar c…
Dynamical formation and stability of fermion-boson stars
Fabrizio Di Giovanni, Saeed Fakhry, Nicolas Sanchis-Gual +2
Gravitationally bound structures composed by fermions and scalar particles known as fermion-boson stars are regular and static configurations obtained by solving the coupled Einste…
Dynamical -boson stars: generic stability and evidence for non-spherical solutions
Víctor Jaramillo, Nicolas Sanchis-Gual, Juan Barranco +4
-boson stars are static, spherical, multi-field self-gravitating solitons. They are asymptotically flat, finite energy solutions of Einstein's gravity minimally coupled to an…
Geodesic structure of a rotating regular black hole
Brandon Bautista-Olvera, Juan Carlos Degollado, Gabriel German
We examine the dynamics of particles around a rotating regular black hole. In particular we focus on the effects of the characteristic length parameter of the spinning black hole o…
Dynamical evolutions of -boson stars in spherical symmetry
Miguel Alcubierre, Juan Barranco, Argelia Bernal +5
In previous work, we have found new static, spherically symmetric boson star solutions which generalize the standard boson stars by allowing a particular superposition of scalar fi…
Traversable -wormholes supported by ghost scalar fields
Belen Carvente, Víctor Jaramillo, Juan Carlos Degollado +2
We present new, asymptotically flat, static, spherically symmetric and traversable wormhole solutions in General Relativity which are supported by a family of ghost scalar fields w…