39 citations · 224 across the 14 of their papers we have counts for
14 papers
The near equilibrium Einstein-Boltzmann system with a simplified collision term
Philip Semrén, Michael Bradley, João M. S. Oliveira +1
A simplified relativistic kinetic theory for gases with internal degrees of freedom, based on a BGK-type collision term, is considered. First the Boltzmann equation is rewritten in…
Energy bounds and ergoregion instability in Einstein-Maxwell-Scalar field models
Filipe C. Mena, João M. Oliveira
We investigate energy bounds and the stability of stationary asymptotically flat spacetimes with an ergoregion and no future horizon in the context of Einstein-Maxwell-Scalar field…
Reaction-diffusion systems derived from kinetic theory for Multiple Sclerosis
Romina Travaglini, João Miguel Oliveira
We present a mathematical study for the development of Multiple Sclerosis in which a spatio-temporal kinetic { theory} model describes, at the mesoscopic level, the dynamics of a h…
Scalaroca stars: coupled scalar-Proca solitons
Alexandre M. Pombo, João M. S. Oliveira, Nuno M. Santos
We construct and explore the physical properties of \textit{scalaroca stars}: spherically symmetric solitonic solutions made of a complex scalar field and a complex Proca field…
A convenient gauge for virial identities in axial symmetry
Joao M. S. Oliveira, Alexandre M. Pombo
Virial identities are a useful mathematical tool in General Relativity. Not only have they been used as a numerical accuracy tool, but they have also played a significant role in e…
Deconstructing scaling virial identities in General Relativity: spherical symmetry and beyond
Carlos A. R. Herdeiro, João M. S. Oliveira, Alexandre M. Pombo +1
Derrick-type virial identities, obtained via dilatation (scaling) arguments, have a variety of applications in field theories. We deconstruct such virial identities in relativistic…
Virial identities in relativistic gravity: 1D effective actions and the role of boundary terms
Carlos A. R. Herdeiro, João M. S. Oliveira, Alexandre M. Pombo +1
Virial (aka scaling) identities are integral identities that are useful for a variety of purposes in non-linear field theories, including establishing no-go theorems for solitonic…
Spontaneous vectorization of electrically charged black holes
João M. S. Oliveira, Alexandre M. Pombo
In this work, we generalise the spontaneous scalarization phenomena in Einstein-Maxwell-Scalar models to a higher spin field. The result is an Einstein-Maxwell-Vector model wherein…
Higher dimensional black hole scalarization
Dumitru Astefanesei, Carlos Herdeiro, João Oliveira +1
In the simplest scalar-tensor theories, wherein the scalar field is non-minimally coupled to the Ricci scalar, spontaneous scalarization of electrovacuum black holes (BHs) does not…
Electromagnetic dual Einstein-Maxwell-scalar models
Carlos A. R. Herdeiro, João M. S. Oliveira
Electromagnetic duality is discussed in the context of Einstein-Maxwell-scalar (EMS) models including axionic-type couplings. This family of models introduces two non-minimal coupl…
A class of solitons in Maxwell-scalar and Einstein-Maxwell-scalar models
Carlos A. R. Herdeiro, João M. S. Oliveira, Eugen Radu
Recently, no-go theorems for the existence of solitonic solutions in Einstein-Maxwell-scalar (EMS) models have been established in arXiv:1902.07721. Here we discuss how these theor…
On the inexistence of self-gravitating solitons in generalised axion electrodynamics
Carlos A. R. Herdeiro, João M. S. Oliveira
Building upon the methods used recently, we establish the inexistence of self-gravitating solitonic solutions for both static and strictly stationary asymptotically flat spacetimes…
On the inexistence of solitons in Einstein-Maxwell-scalar models
Carlos A. R. Herdeiro, João M. S. Oliveira
Three non-existence results are established for self-gravitating solitons in Einstein-Maxwell-scalar models, wherein the scalar field is, generically, non-minimally coupled to the…
Radiative gravitational collapse to spherical, toroidal and higher genus black holes
Filipe C. Mena, João M. Oliveira
We derive the matching conditions between FLRW and generalised Vaidya spacetimes with spherical, planar or hyperbolic symmetry, across timelike hypersurfaces. We then construct new…