62 citations · 390 across the 34 of their papers we have counts for
34 papers
Astrophysical cloaking of a naked singularity
Ronaldo S. S. Vieira, Włodek Kluźniak
A massive naked singularity would be cloaked by accreted matter, and thus may appear to a distant observer as an opaque \mbox{(quasi-)}spherical surface of a fluid, not unlike that…
Envelopes for orbits around axially symmetric sources with spheroidal shape
Javier Ramos-Caro, Ronaldo S. S. Vieira
We introduce a method to obtain the envelopes of eccentric orbits in axially symmetric potentials, , endowed with -symmetry of reflection. By making the transformation $…
Chaotic dynamics of a spinless axisymmetric extended body around a Schwarzschild black hole
Ricardo A. Mosna, Fernanda F. Rodrigues, Ronaldo S. S. Vieira
We investigate the long-term orbital dynamics of spinless extended bodies in Schwarzschild geometry, and show that periodic deviations from spherical symmetry in the shape of a tes…
Homoclinic chaos in the Hamiltonian dynamics of extended test bodies
Ronaldo S. S. Vieira, Ricardo A. Mosna
There is a long tradition of studying chaotic trajectories in systems whose integrability is broken by means of an external perturbation. Here we explore a different route to chaos…
Chaotic orbital dynamics of pulsating objects in dark matter halos
Ronaldo S. S. Vieira, Ricardo A. Mosna
Stellar pulsation is nowadays a widely understood subject. However, there has been no research about the effects of pulsations on the star's orbital dynamics throughout the galaxy.…
Levitating atmospheres around naked singularities
Ronaldo S. S. Vieira, Włodek Kluźniak
For a wide class of spherically symmetric naked singularities there is a sphere within which gravity is effectively repulsive. In such spacetimes accreting matter cannot reach the…
Post-Newtonian Hamiltonian dynamics: applications to stationary spacetimes and statistical mechanics
Ronaldo S. S. Vieira, Javier Ramos-Caro, Alberto Saa
Although the post-Newtonian Lagrangian formalism is widely used in relativistic dynamical and statistical studies of test bodies moving around arbitrary mass distributions, the cor…
The solutions of the Yang-Baxter equation for the -vertex models through a differential approach
R. S. Vieira, A. Lima-Santos
The formal derivatives of the Yang-Baxter equation with respect to its spectral parameters, evaluated at some fixed point of these parameters, provide us with two systems of differ…
Nonlinear system synchronization to sum signals of multiple chaotic systems
Robson Vieira, Weliton S. Martins, Sergio Barreiro +3
Coupling of chaotic oscillators has evidenced conditions where synchronization is possible, therefore a nonlinear system can be driven to a particular state through input from a si…
Exploring the origin of moving groups and diagonal ridges by simulations of stellar orbits and birthplaces
Douglas A. Barros, Angeles Pérez-Villegas, Jacques R. D. Lépine +2
The present paper is the culminating one of a series aimed to contribute to the understanding of the kinematic structures of the solar neighbourhood (SN), explaining the origin of…
Fifteen-vertex models with non-symmetric matrices
R. S. Vieira
In this work, we employ the algebraic-differential method recently developed by the author to solve the Yang-Baxter equation for arbitrary fifteen-vertex models satisfying the ice-…
Self-gravitating razor-thin disks around black holes via multi-hole seeds
Ronaldo S. S. Vieira
We construct self-gravitating razor-thin disks of counterrotating dust around Schwarzschild black holes (BHs) by applying the "displace, cut, and reflect" method to known seed solu…
Orthogonal polynomials and Möbius transformations
R. S. Vieira, V. Botta
Given an orthogonal polynomial sequence on the real line, another sequence of polynomials can be found by composing these polynomials with a general Möbius transformation. In this…
Envelopes and vertical amplitudes of disk-crossing orbits
Ronaldo S. S. Vieira, Javier Ramos-Caro
We recently found that regular orbits in axially symmetric galactic disks have their envelopes accurately described by the relation , if their am…
Relativistic chaos in the anisotropic harmonic oscillator
Ronaldo S. S. Vieira, Tatiana A. Michtchenko
The harmonic oscillator is an essential tool, widely used in all branches of Physics in order to understand more realistic systems, from classical to quantum and relativistic regim…
On the stellar velocity distribution in the solar neighborhood in the light of Gaia DR2
Tatiana A. Michtchenko, Jacques R. D. Lépine, Angeles Pérez-Villegas +2
The aim of this work is to contribute to the understanding of the stellar velocity distribution in the solar neighborhood (SN). We propose that the structures on the planes,…
Combined dynamical effects of the bar and spiral arms in a Galaxy model. Application to the solar neighbourhood
Tatiana A. Michtchenko, Jacques R. D. Lépine, Douglas A. Barros +1
Observational data indicate that the Milky Way is a barred spiral galaxy. Computation facilities and availability of data from Galactic surveys stimulate the appearance of models o…
Boundary Algebraic Bethe Ansatz for a nineteen vertex model with symmetry
R. S. Vieira, A. Lima Santos
The boundary algebraic Bethe Ansatz for a supersymmetric nineteen vertex-model constructed from a three-dimensional representation of the twisted quantum affine Lie superalgebra $U…
The dynamical origin of the Local arm and the Sun's trapped orbit
Jacques R. D. Lépine, Tatiana A. Michtchenko, Douglas A. Barros +1
The Local arm of the Milky Way, a short spiral feature near the Sun whose existence is known for decades, was recently observed in detail with different tracers. Many efforts have…
Reflection -matrices for a nineteen vertex model with symmetry
R. S. Vieira, A. Lima Santos
We derive the solutions of the boundary Yang-Baxter equation associated with a supersymmetric nineteen vertex model constructed from the three-dimensional representation of the twi…
Curvature dependence of relativistic epicyclic frequencies in static, axially symmetric spacetimes
Ronaldo S. S. Vieira, Włodek Kluźniak, Marek Abramowicz
The sum of squared epicyclic frequencies of nearly circular motion () in axially symmetric configurations of Newtonian gravity is known to depend both on the matter de…
Vertical stability of circular orbits in relativistic razor-thin disks
Ronaldo S. S. Vieira, Javier Ramos-Caro, Alberto Saa
During the last few decades, there has been a growing interest in exact solutions of Einstein equations describing razor-thin disks. Despite the progress in the area, the analytica…
Solution of Supplee's submarine paradox through special and general relativity
R. S. Vieira
In 1989 Supplee described an apparent relativistic paradox on which a submarine seems to sink to observers at rest within the ocean, but it rather seems to float in the submarine p…
Modelling resonances and orbital chaos in disk galaxies. Application to a Milky Way spiral model
Tatiana A. Michtchenko, Ronaldo S. S. Vieira, Douglas A. Barros +1
Context: Resonances in the stellar orbital motion under perturbations from spiral arms structure play an important role in the evolution of the disks of spiral galaxies. The epicyc…