Relativistic breather-like solitary waves with linear polarization in cold plasmas

TL;DR

This paper presents new exact numerical solutions for linearly polarized, breather-like solitary waves in cold plasmas, revealing their energy exchange dynamics and stability through detailed analysis and simulations.

Contribution

It introduces a novel class of exact nonlinear solutions for linearly polarized solitary waves in cold plasmas, highlighting their breather-like behavior and energy exchange mechanisms.

Findings

Solutions exist within a specific frequency range

Waves exhibit periodic energy exchange at twice the wave frequency

Numerical simulations confirm long-term propagation stability

Abstract

Linearly polarized solitary waves, arising from the interaction of an intense laser pulse with a plasma, are investigated. New localized structures, in the form of exact \Changes{numerical} nonlinear solutions of the one-dimensional Maxwell-fluid model for a cold plasma with fixed ions are presented. Unlike stationary circularly polarized solitary waves, the linear polarization gives rise to a breather-like behavior and a periodic exchange of electromagnetic energy and electron kinetic energy at twice the frequency of the wave. A numerical method based on a finite-differences scheme allows to compute a branch of solutions within the frequency range $\Omega_{min}<\Omega<\omega_{pe}$, where $\omega_{pe}$ and $\Omega_{min}$ are the electron plasma frequency and the frequency value for which the plasma density vanishes locally, respectively. A detailed description of the spatio-temporal structure of the waves and their main properties as a function of $\Omega$ are presented. Direct numerical simulations of the Maxwell-fluid model show that these solitary waves propagate without change for a long time.