Browsing Exact and Earth Sciences by Author "Haas, Fernando"
Now showing items 21-31 of 31
-
Multi-Hamiltonian structure of the epidemics model accounting for vaccinations and a suitable test for the accuracy of its numerical solvers
Haas, Fernando; Kröger, Martin; Schlickeiser, Reinhard (2022) [Journal article]We derive a generalized Hamiltonian formalism for a modified suscepti ble–infectious–recovered/removed (SIR) epidemic model taking into account the population V of vaccinated persons. The resulting SIRV model is shown to ... -
Neutrino-driven electrostatic instabilities in a magnetized plasma
Haas, Fernando; Pascoal, Kellen Alves; Mendonça, José Tito (2017) [Journal article]The destabilizing role of neutrino beams on the Trivelpiece-Gould modes is considered, assuming electrostatic perturbations in a magnetized plasma composed by electrons in a neutralizing ionic background, coupled to a ... -
Neutrino magnetohydrodynamics
Haas, Fernando; Pascoal, Kellen Alves; Mendonça, José Tito (2016) [Journal article]A new neutrino magnetohydrodynamics (NMHD) model is formulated, where the effects of the charged weak current on the electron-ion magnetohydrodynamic fluid are taken into account. The model incorporates in a systematic way ... -
Neutrino oscillations and instabilities in degenerate relativistic astrophysical plasmas
Haas, Fernando (2019) [Journal article]We set up a proposal to extend significantly recent works on neutrino-plasma interaction, allowing the possibility of deep degenerate and relativistic electrons, which are often present in compact stars such as high-density ... -
Nonlinear dynamics in isotropic and anisotropic nagneto-optical traps
Haas, Fernando; Soares, Luiz Gustavo Ferreira (2022) [Journal article]We briefly review some recent advances in the field of nonlinear dynamics of atomic clouds in magneto-optical traps. A hydrodynamical model in a three-dimensional geometry is applied and analyzed using a variational approach. ... -
Nonlinear ion-acoustic solitons in a magnetized quantum plasma with arbitrary degeneracy of electrons
Haas, Fernando; Mahmood, Shahzad (2016) [Journal article]Nonlinear ion-acoustic waves are analyzed in a nonrelativistic magnetized quantum plasma with arbitrary degeneracy of electrons. Quantum statistics is taken into account by means of the equation of state for ideal fermions ... -
Relativistic Ermakov–Milne–Pinney Systems and First Integrals
Haas, Fernando (2021) [Journal article]The Ermakov–Milne–Pinney equation is ubiquitous in many areas of physics that have an explicit time-dependence, including quantum systems with time-dependent Hamiltonian, cosmology, time-dependent harmonic oscillators, ... -
Relativistic theory for localized electrostatic excitations in degenerate electron-ion plasmas
Mc Kerr, Michael; Haas, Fernando; Kourakis, Ioannis (2014) [Journal article]A self-consistent relativistic two-fluid model is proposed for electron-ion plasma dynamics. A one-dimensional geometry is adopted. Electrons are treated as a relativistically degenerate fluid, governed by an appropriate ... -
Sobre a integrabilidade de problemas em mecânica clássica com dependência temporal explícita
Haas, Fernando; Goedert, Joao (1999) [Journal article]Transformações canônicas generalizadas são apresentadas como uma extensão simples das transformaçõoes canônicas usuais. Este artifício reduz uma classe extensa de sistemas com dependência temporal explícita em sistemas ... -
Trapping and instability of directional gravity waves in localized water currents
Eliasson, Bengt; Haas, Fernando (2014) [Journal article]The influence of localizedwater currents on the nonlinear dynamics and stability of large amplitude, statistically distributed gravity waves is investigated theoretically and numerically by means of an evolution equation ... -
Weakly nonlinear ion-acoustic excitationsin a relativistic modelfor dense quantum plasma
Behery, Ebraheem Ebraheem; Haas, Fernando; Kourakis, Ioannis (2016) [Journal article]The dynamics of linear and nonlinear ionic-scale electrostatic excitations propagating in a magnetized relativistic quantum plasma is studied. A quantum-hydrodynamic model is adopted and degenerate statistics for the ...