Relativistic degenerate effects of electrons and positrons on modulational instability of quantum ion acoustic waves in dense plasmas with two polarity ions*
Liu Tie-Lu, Wang Yun-Liang†, Lu Yan-Zhen
       
Modulational instability regions (shadowed parts) in the ultrarelativistic case with γ = 4/3 for different ratios of negative ion temperature to positive ion temperature: σ = 1.0 (a), 2.0 (b), 3.0 (c), and 4.0 (d).