522 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Instituto Superior TécnicoPT53 papers
- University of LisbonPT24 papers
- Centro de MatemáticaPT10 papers
- Universidade Técnica de LisboaPT9 papers
- University of MinhoPT9 papers
- Iscte – Instituto Universitário de LisboaPT4 papers
- Universidade do PortoPT4 papers
- Universidade Federal do Rio de JaneiroBR3 papers
- University of TurinIT3 papers
- Centre National de la Recherche ScientifiqueFR2 papers
- Heriot-Watt UniversityGB2 papers
- Istituto Nazionale di Fisica Nucleare, Sezione di TorinoIT2 papers
17 papers · 1 filter
Primordial magnetic fields in theories of gravity with non-minimal coupling between curvature and matter
Orfeu Bertolami, Maria Margarida Lima, Filipe C. Mena
The existence of magnetic fields in the universe is unmistakable. They are observed at all scales from stars to galaxy clusters. However, the origin of these fields remains enigmat…
Quasinormal modes and stability of boosted Reissner-Nordström AdS black holes
Rodrigo D. B. Fontana, Filipe C. Mena
We investigate the numerical stability of accelerated AdS black holes against linear scalar perturbations. In particular, we study the evolution of a probe non-minimally coupled sc…
Stability of the Cauchy horizon in accelerating black-hole spacetimes
Kyriakos Destounis, Rodrigo D. B. Fontana, Filipe C. Mena
The extendibility of spacetime and the existence of weak solutions to the Einstein field equations beyond Cauchy horizons, is a crucial ingredient to examine the limits of General…
Global dynamics of Yang-Mills field and perfect-fluid Robertson-Walker cosmologies
Artur Alho, Vitor Bessa, Filipe C. Mena
We apply a new global dynamical systems formulation to flat Robertson-Walker cosmologies with a massless and massive Yang-Mills field and a perfect-fluid with linear equation of st…
Singularity theorems and the inclusion of torsion in affine theories of gravity
Paulo Luz, Filipe C. Mena
We extend the scope of the Raychaudhuri-Komar singularity theorem of General Relativity to affine theories of gravity with and without torsion. We first generalize the existing foc…
Strong Cosmic Censorship in Horndeski Theory
Kyriakos Destounis, Rodrigo D. B. Fontana, Filipe C. Mena +1
The strong cosmic censorship hypothesis has recently regained a lot of attention in charged and rotating black holes immersed in de Sitter space. Although the picture seems to be c…
Covariant and gauge-invariant linear scalar perturbations in multiple scalar field cosmologies
Artur Alho, Filipe C. Mena
We derive a set of equations monitoring the evolution of covariant and gauge-invariant linear scalar perturbations of Friedman-Lemaître-Robertson-Walker models with multiple intera…
The spherically symmetric Einstein-scalar field system with positive and vanishing cosmological constant: a comparison
João L. Costa
We review recent results concerning the spherically symmetric Einstein-scalar field system with positive cosmological constant. We do so by comparing with the classical results of…
Theory of intersecting loops on a torus
J. E. Nelson, R. F. Picken
We continue our investigation into intersections of closed paths on a torus, to further our understanding of the commutator algebra of Wilson loop observables in 2+1 quantum gravit…
Optimal escape from circular orbits around black holes
Jose Natario
Using the theory of optimal rocket trajectories in general relativity, recently developed in arXiv:1105.5235, we show that the "obvious" manoeuvre of using a tangential instantaneo…
Gravito-electromagnetic analogies
L. Filipe O. Costa, José Natário
We reexamine and further develop different gravito-electromagnetic (GEM) analogies found in the literature, and clarify the connection between them. Special emphasis is placed in t…
The problem of a self-gravitating scalar field with positive cosmological constant
Joao L. Costa, Artur Alho, Jose Natario
We study the Einstein-scalar field system with positive cosmological constant and spherically symmetric characteristic initial data given on a truncated null cone. We prove well-po…
Stationary Black Holes: Uniqueness and Beyond
Piotr T. Chruściel, João Lopes Costa, Markus Heusler
The spectrum of known black-hole solutions to the stationary Einstein equations has been steadily increasing, sometimes in unexpected ways. In particular, it has turned out that no…
Spherical linear waves in de Sitter spacetime
Joao L. Costa, Artur Alho, Jose Natario
We apply Christodoulou's framework, developed to study the Einstein-scalar field equations in spherical symmetry, to the linear wave equation in de Sitter spacetime, as a first ste…
Optimal time travel in the Godel universe
Jose Natario
Using the theory of optimal rocket trajectories in general relativity, recently developed in arXiv:1105.5235, we present a candidate for the minimum total integrated acceleration c…
A Quantum Goldman Bracket for Loops on Surfaces
J. E. Nelson, R. F. Picken
In the context of (2+1)--dimensional gravity, we use holonomies of constant connections which generate a --deformed representation of the fundamental group to derive signed area…
Painleve-Gullstrand Coordinates for the Kerr Solution
Jose Natario
We construct a coordinate system for the Kerr solution, based on the zero angular momentum observers dropped from infinity, which generalizes the Painleve-Gullstrand coordinate sys…