Zobrazeno 1 - 10
of 695
pro vyhledávání: '"Ronaldo, S."'
Publikováno v:
Gen. Rel. Grav. 56:112 (2024)
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 gravity. We show that a spherically symmetric pulsating ball may have c
Externí odkaz:
http://arxiv.org/abs/2409.14667
Publikováno v:
Revista Brasileira de Ensino de F\'isica, vol. 46, e20240229 (2024)
Non-linear dynamics is not a usually covered topic in undergraduate physics courses. However, its importance within classical mechanics and the general theory of dynamical systems is unquestionable. In this work we show that this subject can be inclu
Externí odkaz:
http://arxiv.org/abs/2407.02526
Autor:
Vieira, Ronaldo S. S., Wielgus, Maciek
Publikováno v:
Physical Review D 110, 064010 (2024)
We study trajectories of test particles around a luminous, static, spherically symmetric neutron star, under the combined influence of gravity and radiation. In general relativity, for Schwarzschild spacetime, an equilibrium sphere (the Eddington Cap
Externí odkaz:
http://arxiv.org/abs/2403.01006
Publikováno v:
Bull. Soc. R. Sci. Liege, 2023, 92(2), 1 - 4
We present an update of the grid of detailed atmosphere models and homogeneous synthetic spectra for hot, high-gravity subdwarf stars. High-resolution spectra and synthetic photometry were calculated in the wavelength range 1,000 \r{A} - 10,000 \r{A}
Externí odkaz:
http://arxiv.org/abs/2307.08362
Publikováno v:
MNRAS 523, 4615--4623 (2023)
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 of a star or planet. We present here analytical solutions for levitat
Externí odkaz:
http://arxiv.org/abs/2304.05932
Autor:
Mishra, Ruchi, Vieira, Ronaldo S. S.
In General Relativity, the gravitational field of an electrically charged, non-rotating, spherically symmetric body is described by the Reissner-Nordstrom (RN) metric. In the naked-singularity regime, a general property of this metric is the existenc
Externí odkaz:
http://arxiv.org/abs/2304.04313
We introduce a method to obtain the envelopes of eccentric orbits in axially symmetric potentials, $\Phi(R,z)$, endowed with $z$-symmetry of reflection. By making the transformation $z\rightarrow a+\sqrt{a^{2}+ z^{2}}$, with $a>0$, we compute the res
Externí odkaz:
http://arxiv.org/abs/2302.02739
Autor:
Eliane A. Morais, Maykon A. Lemes, Natalilian R. S. Souza, Amando Siuiti Ito, Evandro L. Duarte, Ronaldo S. Silva, Sergio Brochsztain, Jose A. Souza
Publikováno v:
ACS Omega, Vol 9, Iss 20, Pp 22296-22304 (2024)
Externí odkaz:
https://doaj.org/article/1ca5352ad8fa48a895d2519b89bd06d3
Publikováno v:
IJCSR Volume 6, October 2022, ISSN 2546-115X, pages 1-15
The study aims the development of a wearable device to combat the onslaught of covid-19. Likewise, to enhance the regular face shield available in the market. Furthermore, to raise awareness of the health and safety protocols initiated by the governm
Externí odkaz:
http://arxiv.org/abs/2212.08996
Autor:
IRLANE CRISTINE S.A. LIRA, NATONIEL F. DE MELO, RAFAELA PRISCILA ANTONIO, RONALDO S. DE OLIVEIRA, MANOEL A. DE QUEIROZ
Publikováno v:
Anais da Academia Brasileira de Ciências, Vol 96, Iss suppl 1 (2024)
Abstract The genus Stylosanthes has economic importance in semi-arid regions and requires studies that reveal complex relationships between species involving different ploidies. The aim of this study was to cytogenetically investigate accessions of S
Externí odkaz:
https://doaj.org/article/9fc63d28085a49ec877a6d07602f9f93