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A within-host dengue infection model with immune response and nonlinear incidence rate

Hajar Ansari, Mahmoud Hesaaraki (2013)

Applicationes Mathematicae

A model of viral infection of monocytes population by the dengue virus is formulated as a system of four ordinary differential equations. The model takes into account the immune response and nonlinear incidence rate of susceptible and free virus particles. Global stability of the uninfected steady state is investigated. Such a steady state always exists. If it is the only steady state, then it is globally asymptotically stable. If any infected steady state exists, then the uninfected...

A WKB analysis of the Alfvén spectrum of the linearized magnetohydrodynamics equations

Manuel Núñez, Jesús Rojo (1993)

Applications of Mathematics

Small perturbations of an equilibrium plasma satisfy the linearized magnetohydrodynamics equations. These form a mixed elliptic-hyperbolic system that in a straight-field geometry and for a fixed time frequency may be reduced to a single scalar equation div A 1 Δ u + A 2 u = 0 , where A 1 may have singularities in the domaind U of definition. We study the case when U is a half-plane and u possesses high Fourier components, analyzing the changes brought about by the singularity A 1 = . We show that absorptions of energy takes...

Abelian integrals in holomorphic foliations.

Hossein Movasati (2004)

Revista Matemática Iberoamericana

The aim of this paper is to introduce the theory of Abelian integrals for holomorphic foliations in a complex manifold of dimension two. We will show the importance of Picard-Lefschetz theory and the classification of relatively exact 1-forms in this theory. As an application we identify some irreducible components of the space of holomorphic foliations of a fixed degree and with a center singularity in the projective space of dimension two. Also we calculate higher Melnikov functions under some...

Abelian integrals related to Morse polynomials and perturbations of plane hamiltonian vector fields

Lubomir Gavrilov (1999)

Annales de l'institut Fourier

Let 𝒜 be the real vector space of Abelian integrals I ( h ) = { H h } R ( x , y ) d x d y , h [ 0 , h ˜ ] where H ( x , y ) = ( x 2 + y 2 ) / 2 + ... is a fixed real polynomial, R ( x , y ) is an arbitrary real polynomial and { H h } , h [ 0 , h ˜ ] , is the interior of the oval of H which surrounds the origin and tends to it as h 0 . We prove that if H ( x , y ) is a semiweighted homogeneous polynomial with only Morse critical points, then 𝒜 is a free finitely generated module over the ring of real polynomials [ h ] , and compute its rank. We find the generators of 𝒜 in the case when H is an arbitrary cubic polynomial. Finally we...

About differential inequalities for nonlocal boundary value problems with impulsive delay equations

Alexander Domoshnitsky, Irina Volinsky (2015)

Mathematica Bohemica

We propose results about sign-constancy of Green's functions to impulsive nonlocal boundary value problems in a form of theorems about differential inequalities. One of the ideas of our approach is to construct Green's functions of boundary value problems for simple auxiliary differential equations with impulses. Careful analysis of these Green's functions allows us to get conclusions about the sign-constancy of Green's functions to given functional differential boundary value problems, using the...

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