133 citations · 711 across the 43 of their papers we have counts for
43 papers
Polytropic Stars in covariant formulation
J. C. N de Araujo, H. G. M. Fortes
General Relativity (GR) is not the only way gravity can be geometrised. Instead of curvature, the Teleparallel Theory attributes gravity to torsion , which is related to the ant…
On the optical transients from double white-dwarf mergers
M. F. Sousa, J. G. Coelho, J. C. N. de Araujo +2
Double white-dwarf (DWD) mergers are relevant astrophysical sources expected to produce massive, highly-magnetized WDs, supernovae (SNe) Ia, and neutron stars (NSs). Although they…
Mass of compact stars in f(T) gravity
José Carlos Neves de Araujo, Hemily Gomes Marciano Fortes
The mass of compact objects in General Relativity (GR), which as is well known, is obtained via the Tolman - Oppenheimer - Volkov (TOV) equations, is a well defined quantity. Howev…
The double white dwarf merger progenitors of SDSS J2211+1136 and ZTF J1901+1458
M. F. Sousa, J. G. Coelho, J. C. N. de Araujo +2
Double white dwarf (DWD) mergers are possibly the leading formation channel of massive, rapidly rotating, high-field magnetic white dwarfs (HFMWDs). However, the direct link connec…
Solving Tolman-Oppenheimer-Volkoff equations in gravity: a novel approach applied to polytropic equations of state
J. C. N. de Araujo, H. G. M. Fortes
The Teleparallel Theory is an alternative theory of gravity equivalent to General Relativity (GR) and with non-vanishing torsion . Some extensions of this theory, the so-called…
Reconstruction of energy conditions from observations and implications for extended theories of gravity
M. Penna-Lima, S. D. P. Vitenti, M. E. S. Alves +2
The attempt to describe the recent accelerated expansion of the Universe includes different propositions for dark energy models and modified gravity theories. Establish their featu…
Cosmological constant constraints from observation-derived energy condition bounds and their application to bimetric massive gravity
M. E. S. Alves, F. C. Carvalho, J. C. N. de Araujo +2
Among the various possibilities to probe the theory behind the recent accelerated expansion of the universe, the energy conditions (ECs) are of particular interest, since it is pos…
Gravitational Waves from Pulsars and Their Braking Indices: The Role of a Time Dependent Magnetic Ellipticity
José C. N. de Araujo, Jaziel G. Coelho, César A. Costa
We study the role of time dependent magnetic ellipticities () on the calculation of the braking index of pulsars. Moreover, we study the consequences of such a on th…
Gravitational waves from pulsars in the context of magnetic ellipticity
José C. N. de Araujo, Jaziel G. Coelho, César A. Costa
In one of our previous articles we have considered the role of a time dependent magnetic ellipticity on pulsars' braking indices and on the putative gravitational waves these objec…
Gravitational waves from pulsars with measured braking index
Jose C. N. de Araujo, Jaziel G. Coelho, Cesar A. Costa
We study the putative emission of gravitational waves (GWs) in particular for pulsars with measured braking index. We show that the appropriate combination of both GW emission and…
Gravitational waves in the theory of gravity
M. E. S. Alves, P. H. R. S. Moraes, J. C. N. de Araujo +1
There is a host of alternative theories of gravitation in the literature, among them the recently elaborated by Harko and collaborators. In these theories the and …
Master equation solutions in the linear regime of characteristic formulation of general relativity
C. E. Cedeño M., J. C. N. de Araujo
From the field equations in the linear regime of the characteristic formulation of general relativity, Bishop, for a Schwarzschild's background, and Mädler, for a Minkowski's backg…
Primordial Gravitational Waves in Running Vacuum Cosmologies
D. A. Tamayo, J. A. S. Lima, M. E. S. Alves +1
We investigate the cosmological production of gravitational waves in a nonsingular flat cosmology powered by a "running vacuum" energy density described by , a phe…
Point Particle Binary System with Components of Different Masses in the Linear Regime of the Characteristic Formulation of General Relativity
C. E. Cedeño M., J. C. N. de Araujo
A study of binary systems composed of two point particles with different masses in the linear regime of the characteristic formulation of general relativity in a Minkowski backgrou…
Flood avalanches in a semiarid basin with a dense reservoir network
Samuel J. Peter, J. C. de Araújo, N. A. M. Araújo +1
This study investigates flood avalanches in a dense reservoir network in the semiarid north-eastern Brazil. The population living in this area strongly depends on the availability…
Ondas gravitacionales y objetos compactos (Gravitational waves and compact objects)
J. C. N. de Araujo
It is presented a brief review on gravitational waves (GWs). It is shown how the wave equation is obtained from Einstein's equations and how many and how are the polarization modes…
A Recipe to Probe Alternative Theories of Gravitation via N-body Numerical Simulations. I. Spiral Galaxies
C. S. S. Brandao, J. C. N. de Araujo
A way to probe alternative theories of gravitation is to study if they could account for the structures of the universe. We then modified the well-known Gadget-2 code to probe alte…
Overspill avalanching in a dense reservoir network
G. L. Mamede, N. A. M. Araújo, C. M. Schneider +2
Sustainability of communities, agriculture, and industry is strongly dependent on an effective storage and supply of water resources. In some regions the economic growth has led to…
Coalescence Rate of Supermassive Black Hole Binaries Derived from Cosmological Simulations: Detection Rates for LISA and ET
Ch. Filloux, J. A. de Freitas Pacheco, F. Durier +1
The coalescence history of massive black holes has been derived from cosmological simulations, in which the evolution of those objects and that of the host galaxies are followed in…
Isotropisation of Quadratic Gravity: Scalar and Tensor Components
Daniel Müller, Márcio E. S. Alves, José C. N. de Araujo
It is believed that soon after the Planck era, spacetime should have a semi-classical nature. Therefore, it is unavoidable to modify the theory of General Relativity or look for al…
Gravitational Waves in Braneworld Scenarios with AdS Background
A. C. Amaro de Faria, Roldao da Rocha, M. E. S. Alves +1
In this paper, we investigate gravitational waves as metric perturbations around a general warped 5-dimensional background. We find an analytical solution in Randall-Sundrum branew…
Observational Constraints on Visser's Cosmological Model
Marcio E. S. Alves, Fabio C. Carvalho, Jose C. N. de Araujo +3
Theories of gravity for which gravitons can be treated as massive particles have presently been studied as realistic modifications of General Relativity, and can be tested with cos…
Probing Brownstein-Moffat Gravity via Numerical Simulations
C. S. S. Brandao, J. C. N. de Araujo
In the standard scenario of the Newtonian gravity, a late-type galaxy (i.e., a spiral galaxy) is well described by a disk and a bulge embedded in a halo mainly composed by dark mat…
Extra polarization states of cosmological gravitational waves in alternative theories of gravity
Marcio E. S. Alves, Oswaldo D. Miranda, Jose C. N. de Araujo
Cosmological Gravitational Waves (GWs) are usually associated with the transverse-traceless part of the metric perturbations in the context of the theory of cosmological perturbati…