Fluid simulation of ion acoustic solitary waves in electron–positron–ion plasma Kuldeep Singh, Amar Kakad, Bharati Kakad and N. S. Saini Eur. Phys. J. Plus, 136 1 (2021) 14 Published online: 02 January 2021 DOI: 10.1140/epjp/s13360-020-00941-4