2k citations · 12k across the 281 of their papers we have counts for
14 papers · 1 filter
Noncommutative Black Holes and the Singularity Problem
C. Bastos, O. Bertolami, N. C. Dias +1
A phase-space noncommutativity in the context of a Kantowski-Sachs cosmological model is considered to study the interior of a Schwarzschild black hole. Due to the divergence of th…
Non-Canonical Phase-Space Noncommutativity and the Kantowski-Sachs singularity for Black Holes
Catarina Bastos, Orfeu Bertolami, Nuno Costa Dias +1
We consider a cosmological model based upon a non-canonical noncommutative extension of the Heisenberg-Weyl algebra to address the thermodynamical stability and the singularity pro…
Noncommutative Black Holes
C. Bastos, O. Bertolami, N. C. Dias +1
One considers phase-space noncommutativity in the context of a Kantowski-Sachs cosmological model to study the interior of a Schwarzschild black hole. It is shown that the potentia…
Entropic Gravity, Phase-Space Noncommutativity and the Equivalence Principle
Catarina Bastos, Orfeu Bertolami, Nuno Costa Dias +1
We generalize E. Verlinde's entropic gravity reasoning to a phase-space noncommutativity set-up. This allow us to impose a bound on the product of the noncommutative parameters bas…
Reheating via a generalized non-minimal coupling of curvature to matter
Orfeu Bertolami, Pedro Frazão, Jorge Páramos
In this work one shows that a generalized non-minimal coupling between geometry and matter is compatible with Starobinsky inflation and leads to a successful process of preheating,…
Unparticle inspired corrections to the Gravitational Quantum Well
A. Alves, O. Bertolami
We consider unparticle inspired corrections of the type to the Newtonian potential in the context of the gravitational quantum well. The new energy spectrum…
Using global positioning systems to test extensions of General Relativity
O. Bertolami, J. Páramos
We consider the feasibility of using the Galileo Navigation Satellite System to constrain possible extensions or modifications to General Relativity, by assessing the impact of the…
The Spirit of Unification: The Wei of Physics
Orfeu Bertolami
We review, in a historical perspective, developments in physics which led to the emergence of unifying ideas and theories. Some attention is paid to the theoretical programme that…
Gamma-Ray Bursts and Dark Energy - Dark Matter interaction
T. Barreiro, O. Bertolami, P. Torres
In this work Gamma Ray Burst (GRB) data is used to place constraints on a putative coupling between dark energy and dark matter. Type Ia supernovae (SNe Ia) constraints from the Sl…
Dark matter as a dynamic effect due to a non-minimal gravitational coupling with matter
Orfeu Bertolami, Jorge Páramos
In this work the phenomenology of models possessing a non-minimal coupling between matter and geometry is discussed, with a particular focus on the possibility of describing the fl…
Accelerated expansion from a non-minimal gravitational coupling to matter
O. Bertolami, P. Frazao, J. Páramos
It is shown that a non-minimal coupling between the scalar curvature and the matter Lagrangian density may account for the accelerated expansion of the Universe and provide, throug…
Noncommutative effects in astrophysical objects: a survey
Orfeu Bertolami, Carlos A. D. Zarro
The main implications of noncommutativity over astrophysical objects are examined. Noncommutativity is introduced through a deformed dispersion relation $E^{2}=p^{2}c^{2}(1+λE)^{2}…
Naturalness and stability of the generalized Chaplygin gas in the seesaw cosmon scenario
Alex E. Bernardini, O. Bertolami
The seesaw mechanism is conceived on the basis that a mass scale, , and a dimensionless scale, , can be fine-tuned in order to control the dynamics of active and sterile neut…
Cosmological thinking: cultural heritage and challenge
Orfeu Bertolami
The limitations of current technology do not allow one to foresee the expansion of the humankind beyond our planet for at least a few decades. Furthermore, the laws of physics, as…