189 citations · 954 across the 20 of their papers we have counts for
20 papers
Revisiting Unimodular Quantum Cosmology
Júlio C. Fabris, Luiz Filipe Guimarães, Nelson Pinto-Neto +1
The quantization of unimodular gravity in minisuperspace leads to a time evolution of states generated by the Hamiltonian, as in usual quantum mechanics. We revisit the analysis ma…
Spherically Symmetric Configurations in Unimodular Gravity
Júlio C. Fabris, Mahamadou Hamani Daouda, Hermano Velten
Unimodular gravity (UG) is considered, under many aspects, equivalent to General Relativity (GR), even if the theory is invariant under a more restricted diffeomorphic class of tra…
Brans-Dicke unimodular gravity
Alexandre M. R. Almeida, Júlio C. Fabris, Mahamadou Hamani Daouda +3
We propose a unimodular version of the Brans-Dicke theory designed with a constrained Lagrangian formulation. The resulting field equations are traceless. The vacuum solutions in t…
Nonconservative unimodular gravity: Gravitational waves
Júlio C. Fabris, Marcelo H. Alvarenga, Mahamadou Hamani-Daouda +1
Unimodular gravity is characterized by an extra condition with respect to General Relativity: the determinant of the metric is constant. This extra condition leads to a more restri…
Nonconservative traceless type gravity
Mahamadou Daouda, J. C. Fabris, A. M. Oliveira +2
Extensions of the gravity theory in order to obtain traceless field equations have been widely considered in the literature. The leading example of such class of theories is the un…
Introducing quantum effects in classical theories
J. C. Fabris, O. F. Piattella, D. C. Rodrigues +2
In this paper, we explore two different ways of implementing quantum effects in a classical structure. The first one is through an external field. The other one is modifying the cl…
The Brans-Dicke-Rastall theory
Thiago R. P. Caramês, Mahamadou H. Daouda, Júlio C. Fabris +3
We formulate a theory combining the principles of a scalar-tensor gravity and Rastall's proposal of a violation of the usual conservation laws. We obtain a scalar-tensor theory wit…
Rastall's Cosmology and its Observational Constraints
J. C. Fabris, O. F. Piattella, D. C. Rodrigues +1
The Rastall's theory is a modification of General Relativity touching one of the cornestone of gravity theory: the conservation laws. In Rastall's theory, the energy-momentum tenso…
Rastall cosmology
J. C. Fabris, O. F. Piattella, D. C. Rodrigues +2
We review the difficulties of the generalized Chaplygin gas model to fit observational data, due to the tension between background and perturbative tests. We argue that such issues…
Inhomogeneous Universe in f(T) Theory
Manuel E. Rodrigues, M. Hamani Daouda, M. J. S. Houndjo +2
We obtain the equations of motions of the theory considering the Lemaître-Tolman-Bondi's metric for a set of diagonal and non-diagonal tetrads. In the case of diagonal tetra…
Scalar models for the unification of the dark sector
Mahamadou H. Daouda, Julio C. Fabris, Oliver F. Piattella
We review the difficulties of the generalized Chaplygin gas model to fit observational data, due to the tension between background and perturbative tests. We argue that such issues…
Anisotropic fluid for a set of non-diagonal tetrads in f(T) gravity
M. Hamani Daouda, Manuel E. Rodrigues, M. J. S. Houndjo
We consider gravity for a Weitzenbock spherically symmetric and static spacetime, where the metric is projected in the tangent space to the manifold for a set of non-diagona…
Rastall Cosmology and the ΛCDM Model
Carlos E. M. Batista, Mahamadou H. Daouda, Júlio C. Fabris +2
Rastall's theory is based on the non-conservation of the energy-momentum tensor. We show that, in this theory, if we introduce a two-fluid model, one component representing vacuum…
Reconstruction of f(T) gravity according to holographic dark energy
M. Hamani Daouda, Manuel E. Rodrigues, M. J. S. Houndjo
We develop the reconstruction of a model of gravity according to the holographic dark energy. is the torsion scalar and its initial value from the Teleparallel gravity i…
New Black Holes Solutions in a Modified Gravity
M. Hamani Daouda, Manuel E. Rodrigues, M. J. S. Houndjo
We present a theory of modified gravity, inspired by the gauge theories, where the commutator algebra of covariant derivative gives us an added term with respect to the General Rel…
Note on the Evolution of the Gravitational Potential in Rastall Scalar Field Theories
J. C. Fabris, M. Hamani Daouda, O. F. Piattella
We investigate the evolution of the gravitational potential in Rastall scalar field theories. In a single component model a consistent perturbation theory, formulated in the newton…
Static Anisotropic Solutions in f(T) Theory
M. Hamani Daouda, Manuel E. Rodrigues, M. J. S. Houndjo
In a previously work, we undertook a static and anisotropic content in theory and obtained new spherically symmetric solutions considering a constant torsion and some partic…
New Static Solutions in f(T) Theory
M. Hamani Daouda, Manuel E. Rodrigues, M. J. S. Houndjo
We consider the equations of motion of an anisotropic space-time in theory, where is the torsion. New spherically symmetric solutions of black holes and wormholes are ob…
Scalar models for the generalized Chaplygin gas and the structure formation constraints
J. C. Fabris, T. C. C. Guio, M. Hamani Daouda +1
The generalized Chaplygin gas model represents an attempt to unify dark matter and dark energy. It is characterized by a fluid with an equation of state . It can be ob…
Testing the Rastall's theory using matter power spectrum
C. E. M. Batista, J. C. Fabris, M. Hamani Daouda
The Rastall's theory is a modification of the General Relativity theory leading to a different expression for the conservation law in the matter sector compared with the usual one.…