Filamentation instability of ultra-intense linearly polarized laser pulse in electron-positron plasmas

Based on the wave equation of ultra-intense linearly polarized laser pulse propagating in electron-positron plasmas, the filamentation instability was investigated. The nonlinear dispersion relation and the growth rate of instability were derived. The effects of temperature and laser intensity on the growth rate were analyzed. The results show that in an electron-positron plasma, the intensity of the filamentation instability is mainly determined by the competition between the nonlinearity in the interaction and the relativistic light ponderomotive driven density responses.