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Existence of quasilinear relaxation shock profiles in systems with characteristic velocities

Guy Métivier, Benjamin Texier, Kevin Zumbrun (2012)

Annales de la faculté des sciences de Toulouse Mathématiques

We revisit the existence problem for shock profiles in quasilinear relaxation systems in the case that the velocity is a characteristic mode, implying that the profile ODE is degenerate. Our result states existence, with sharp rates of decay and distance from the Chapman–Enskog approximation, of small-amplitude quasilinear relaxation shocks. Our method of analysis follows the general approach used by Métivier and Zumbrun in the semilinear case, based on Chapman–Enskog expansion and the macro–micro...

Heteroclinic orbits in plane dynamical systems

Luisa Malaguti, Cristina Marcelli (2002)

Archivum Mathematicum

We consider general second order boundary value problems on the whole line of the type u ' ' = h ( t , u , u ' ) , u ( - ) = 0 , u ( + ) = 1 , for which we provide existence, non-existence, multiplicity results. The solutions we find can be reviewed as heteroclinic orbits in the ( u , u ' ) plane dynamical system.

Multiple positive solutions for a second order delay boundary value problem on the half-line

K. G. Mavridis, Ch. G. Philos, P. Ch. Tsamatos (2006)

Annales Polonici Mathematici

Second order nonlinear delay differential equations are considered, and Krasnosel'skiĭ's fixed point theorem is used to establish a result on the existence of positive solutions of a boundary value problem on the half-line. This result can be used to guarantee the existence of multiple positive solutions. A specification of the result obtained to the case of second order nonlinear ordinary differential equations as well as to a particular case of second order nonlinear delay differential equations...

On a singular multi-point third-order boundary value problem on the half-line

Zakia Benbaziz, Smail Djebali (2020)

Mathematica Bohemica

We establish not only sufficient but also necessary conditions for existence of solutions to a singular multi-point third-order boundary value problem posed on the half-line. Our existence results are based on the Krasnosel’skii fixed point theorem on cone compression and expansion. Nonexistence results are proved under suitable a priori estimates. The nonlinearity f = f ( t , x , y ) which satisfies upper and lower-homogeneity conditions in the space variables x , y may be also singular at time t = 0 . Two examples of applications...

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