Local and global bifurcation of electron-states

TL;DR

This paper analyzes the bifurcation phenomena of traveling electron layers in the Vlasov-Poisson system, revealing complex bifurcation structures and symmetry-dependent behaviors using bifurcation theory.

Contribution

It applies Crandall-Rabinowitz's Theorem to identify and characterize bifurcation branches of electron-states, including symmetric and asymmetric cases, in a one-dimensional plasma model.

Findings

Existence of bifurcation branches from flat velocity strips.

Symmetry influences the number and nature of bifurcation curves.

Description of pitchfork bifurcations in asymmetric cases.

Abstract

We study the bifurcation of traveling periodic electron layers, that we call electron-states, from symmetric and asymmetric flat velocity strips in the phase space, for the one dimensional Vlasov-Poisson equation with space periodic condition. The boundaries of the constructed solutions are real-analytic and in uniform translation at the same speed in the space direction. These structures are obtained applying Crandall-Rabinowitz's Theorem using either the velocity or geometrical quantities related to the size of the strip as bifurcation parameters. In the first case, we can prove for any fixed symmetry, the emergence of a pair of branches and the local bifurcation diagram has a hyperbolic structure. In the symmetric situation, we find, for any large enough symmetry, one branch whose orientation close to the stationary solution depends on the sign of the prescribed speed of translation. As for the asymmetric case, we find either a countable or a finite number of bifurcation curves according to some constraints related to the prescribed speed of translation. The pitchfork (subcritical or supercritical) bifurcation is also described in this case. Finally, we briefly discuss the global continuation of these branches.