Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Centre National de la Recherche ScientifiqueFR835 papers
- The Ohio State UniversityUS812 papers
- Universidade de São PauloBR798 papers
- Panjab UniversityIN636 papers
- Universidade Federal do ABCBR635 papers
- Istituto Nazionale di Fisica Nucleare, Sezione di TorinoIT634 papers
- Institut National de Physique Nucléaire et de Physique des ParticulesFR603 papers
- Benemérita Universidad Autónoma de PueblaMX594 papers
- European Organization for Nuclear ResearchCH583 papers
- Wayne State UniversityUS576 papers
- Istituto Nazionale di Fisica Nucleare, Sezione di BolognaIT570 papers
- Istituto Nazionale di Fisica Nucleare, Sezione di CataniaIT565 papers
170 papers · 1 filter
Robinson-Trautman spacetimes in (2+1) dimensions
Alberto Saa
We propose a Robinson-Trautman evolution in -dimensional spacetime that retains key structural features of the four-dimensional case. We consider a recently studied exact fa…
Vacuum polarization in the Schwarzschild black hole with a global monopole
Leonardo G. Barbosa, Victor H. M. Ramos, João Paulo M. Pitelli
We investigate vacuum polarization on the event horizon of a Schwarzschild black hole carrying a global monopole. For a massless scalar field in the Hartle-Hawking state and wi…
Unified dynamical system formulations for gravity with applications to nonminimal derivative coupling and -Higgs inflation
Saikat Chakraborty, Sergio E. Jorás, Alberto Saa
Two different dynamical system formulations are presented that can be implemented to analyze a rather large class of modified gravity theories within the generic family.…
Wind-Finslerian structure of black holes
Hengameh R. Dehkordi, Mauricio Richartz, Alberto Saa
Recently, there has been an increasing interest in the Finslerian interpretation of null geodesics in the exterior regions of stationary black holes, particularly through the Zerme…
Stability of the spacetime of a magnetized compact object
Eveling C. Ribeiro, L. Formigari, Marcos R. Ribeiro +5
We investigate the stability of scalar perturbations around a magnetized stationary compact object in General Relativity. The considered object is one of the simplest exact solutio…
Chaotic orbital dynamics of pulsating stars around black holes surrounded by dark matter halos
Tiago S. Amancio, Ricardo A. Mosna, Ronaldo S. S. Vieira
We analyze the orbital dynamics of spherical test bodies in ``black hole surrounded by dark matter halo'' spherically symmetric spacetimes. When the test body pulsates periodically…
Unruh-deWitt detector in impulsive plane wave spacetimes
João Paulo M. Pitelli, Ricardo A. Mosna
We investigate the response function of an inertial Unruh-deWitt detector in an impulsive plane wave spacetime. Through symmetry considerations applied to the Wightman function, we…
The need for a nonlocal expansion in general relativity
Marco Galoppo, Giorgio Torrieri
Motivated by known facts about effective field theory and non-Abelian gauge theory, we argue that the post-Newtonian approximation might fail even in the limit of weak fields and s…
Chaotic dynamics of pulsating spheres orbiting black holes
Fernanda de F. Rodrigues, Ricardo A. Mosna, Ronaldo S. S. Vieira
We study the chaotic dynamics of spinless extended bodies in a wide class of spherically symmetric spacetimes, which encompasses black-hole scenarios in many modified theories of g…
Quasinormal modes and the analytical continuation of non-self-adjoint operators
M. G. Richarte, J. C. Fabris, A. Saa
We briefly review the analytical continuation method for determining quasinormal modes (QNMs) and the associated frequencies in open systems. We explore two exactly solvable cases…
The number of fundamental constants from a spacetime-based perspective
George E. A. Matsas, Vicente Pleitez, Alberto Saa +1
We revisit Duff, Okun, and Veneziano's divergent views on the number of fundamental constants and argue that the issue can be set to rest by having spacetime as the starting point.…
Robin boundary conditions in acoustic BTZ black holes
Christyan C. de Oliveira, Ricardo A. Mosna, João Paulo M. Pitelli
We introduce an analog model for the conformally coupled scalar field on the BTZ black hole. The model is based on the propagation of acoustic waves in a Laval nozzle. Since the BT…
Comment on "Analog Schwarzschild-like geometry in fluids with external pressure''
João Paulo M. Pitelli, Ricardo A. Mosna, Christyan C. de Oliveira +1
In Ref. [1], exact (not only conformally related) analogue models for the Schwarzschild and Reissner-Nordström spacetimes were found. The background non-relativistic fluid flow was…
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…
Analog model for the BTZ black hole
Christyan C. de Oliveira, Ricardo A. Mosna
We present an analog model for the Bañados, Teitelboim, Zanelli (BTZ) black hole based on a hydrodynamical flow. We numerically solve the fully nonlinear hydrodynamic equations of…
Boundary conditions for isolated asymptotically anti-de Sitter spacetimes
Christyan C. de Oliveira, Ricardo A. Mosna, João Paulo M. Pitelli
We revisit the propagation of classical scalar fields in a spacetime which is asymptotically anti-de Sitter. The lack of global hyperbolicity of the underlying background gives ris…
Isochrone spacetimes
Alberto Saa, Roberto Venegeroles
We introduce the relativistic version of the well-known Henon's isochrone spherical models: static spherically symmetrical spacetimes in which all bounded trajectories are isochron…
Unruh-DeWitt detector in
João Paulo M. Pitelli, Bruno S. Felipe, Ricardo A. Mosna
We find the response function and the transition rate for an Unruh-DeWitt detector interacting with a conformal scalar field in global two-dimensional anti--de Sitter (AdS) spaceti…
Analogue models for Schwarzschild and Reissner-Nordström spacetimes
Christyan C. de Oliveira, Ricardo A. Mosna, João Paulo M. Pitelli +1
We present analogue models for the Schwarzschild and Reissner-Nordström (RN) spacetimes based on unidirectional hydrodynamic flows. We show that, with appropriate coordinate transf…
An angular momentum based graviton detector
J. P. M. Pitelli, T. Rick Perche
We show that gravitons with energy , where is the energy gap a localized non-relativistic system, can be detected by finite-time interactions with a detector. Our detector…
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…
Quasinormal modes and self-adjoint extensions of the Schroedinger operator
Júlio C. Fabris, Martín G. Richarte, Alberto Saa
We revisit here the analytical continuation approach usually employed to compute quasinormal modes (QNM) and frequencies of a given potential barrier starting from the bounded…
The Influence of Magnetic Field Geometry in Neutron Stars Crustal Oscillations
Gibran Henrique de Souza, Ernesto Kemp
In this work, we have studied oscillations in the crust of a neutron star which magnetic field has both dipolar and toroidal components, the former extends from the stellar interio…
Particle Production Between Isometric Frames on a Poincaré Patch of
J. P. M. Pitelli, Vitor S. Barroso
In a recent paper [J. P. M. Pitelli, Phys. Rev. D {\bf 99}, 108701 (2019)], one of us showed that the vacuum state associated to conformal fields on a Poicaré patch of anti-de Sitt…