# Heavy ion-acoustic rogue waves in electron-positron multi-ion plasmas

## TL;DR

This paper investigates the formation and properties of heavy ion-acoustic rogue waves in a complex multi-ion plasma, highlighting how nonextensive electron-positron effects influence wave stability and characteristics.

## Contribution

It introduces a theoretical model for HIA rogue waves in multi-ion plasmas considering nonextensive electrons and positrons, deriving conditions for modulational instability and rogue wave formation.

## Key findings

- Nonextensivity significantly affects rogue wave features.
- Conditions for modulational instability are identified.
- Wave amplitude and width are influenced by plasma parameters.

## Abstract

The nonlinear propagation of heavy-ion-acoustic (HIA) waves (HIAWs) in a four component multi-ion plasma (containing inertial heavy negative ions and light positive ions, as well as inertialess nonextensive electrons and positrons) has been theoretically investigated. The nonlinear Schr\"{o}dinger (NLS) equation is derived by employing the reductive perturbation method. It is found that the NLS equation leads to the modulational instability (MI) of HIAWs, and to the formation of HIA rogue waves (HIARWs), which are due to the effects of nonlinearity and dispersion in the propagation of HIAWs. The conditions for MI of HIAWs, and the basic properties of the generated HIARWs are identified. It is observed that the striking features (viz. instability criteria, growth rate of MI, amplitude and width of HIARWs, etc.) of the HIAWs are significantly modified by effects of nonextensivity of electrons and positrons, ratio of light positive ion mass to heavy negative ion mass, ratio of electron number density to light positive ion number density, and ratio of electron temperature to positron temperature, etc. The relevancy of our present investigation to the observations in the space (viz. cometary comae and earth's ionosphere) and laboratory (laser plasma interaction experimental devices) plasmas is pointed out.