Zobrazeno 1 - 10
of 302
pro vyhledávání: '"Viana, Ricardo L"'
Nontwist area-preserving maps violate the twist condition at specific orbits, resulting in shearless invariant curves that prevent chaotic transport. Plasmas and fluids with nonmonotonic equilibrium profiles may be described using nontwist systems, w
Externí odkaz:
http://arxiv.org/abs/2409.00785
Autor:
Leal, Bruno B., Lazarotto, Matheus J., Mugnaine, Michele, de Almeida, Alfredo M. Ozorio, Viana, Ricardo L., Caldas, Iberê L.
In nontwist systems, primary shearless curves act as barriers to chaotic transport. Surprisingly, the onset of secondary shearless curves has been reported in a few twist systems. Meanwhile, we found that, in twist systems, the onset of these seconda
Externí odkaz:
http://arxiv.org/abs/2408.10930
Autor:
Souza, Diogo L. M., Borges, Fernando S., Gabrick, Enrique C., Bentivoglio, Lucas E., Protachevicz, Paulo R., Santos, Vagner dos, Viana, Ricardo L., Caldas, Ibere L., Iarosz, Kelly C., Batista, Antonio M., Kurths, Jürgen
Spiral waves are spatial-temporal patterns that can emerge in different systems as heart tissues, chemical oscillators, ecological networks and the brain. These waves have been identified in the neocortex of turtles, rats, and humans, particularly du
Externí odkaz:
http://arxiv.org/abs/2403.00022
Autor:
Gabrick, Enrique C., Brugnago, Eduardo L., de Souza, Silvio L. T., Iarosz, Kelly C., Szezech Jr., José D., Viana, Ricardo L., Caldas, Iberê L., Batista, Antonio M., Kurths, Jürgen
We study three different strategies of vaccination in a SEIRS (Susceptible--Exposed--Infected--Recovered--Susceptible) seasonal forced model, which are: ($i$) continuous vaccination; ($ii$) periodic short time localized vaccination and ($iii$) period
Externí odkaz:
http://arxiv.org/abs/2402.16883
Autor:
Mugnaine, Michele, Leal, Bruno B., de Almeida, Alfredo M. Ozorio, Viana, Ricardo L., Caldas, Iberê L.
Isochronous islands in phase space emerge in twist Hamiltonian systems as a response to multiple resonant perturbations. According to the Poincar\'e-Birkhoff theorem, the number of islands depends on the system characteristics and the perturbation. W
Externí odkaz:
http://arxiv.org/abs/2312.12552
Autor:
Gabrick, Enrique C., Sales, Matheus R., Sayari, Elaheh, Trobia, José, Lenzi, Ervin K., Borges, Fernando da S., Szezech Jr., José D., Iarosz, Kelly C., Viana, Ricardo L., Caldas, Iberê L., Batista, Antonio M.
In this work, we analyze the effects of fractional derivatives in the chaotic dynamics of a cancer model. We begin by studying the dynamics of a standard model, {\it i.e.}, with integer derivatives. We study the dynamical behavior by means of the bif
Externí odkaz:
http://arxiv.org/abs/2309.04446
For tokamaks with uniform magnetic shear, Martin and Taylor have proposed a symplectic map has been used to describe the magnetic field lines at the plasma edge perturbed by an ergodic magnetic limiter. We propose an analytical magnetic field line ma
Externí odkaz:
http://arxiv.org/abs/2308.00885
Under certain circumstances, the equations for the magnetic field lines can be recast in a canonical form, after defining a suitable field line Hamiltonian. This analogy is extremely useful for dealing with a variety of problems involving magneticall
Externí odkaz:
http://arxiv.org/abs/2308.00821
Nontwist area-preserving maps violate the twist condition along shearless invariant curves, which act as transport barriers in phase space. Recently, some plasma models have presented multiple shearless curves in phase space and these curves can brea
Externí odkaz:
http://arxiv.org/abs/2305.17538
Autor:
Haerter, Pedro, Viana, Ricardo L.
Publikováno v:
Braz J Phys 53, 114 (2023)
Many systems of physical and biological interest are characterized by assemblies of phase oscillators whose interaction is mediated by a diffusing chemical. The coupling effect results from the fact that the local concentration of the mediating chemi
Externí odkaz:
http://arxiv.org/abs/2305.07471