Gravitating polarons in Bose–Einstein condensate: a contribution to the dark matter substance? Sh. N. Mardonov, B. J. Ahmedov and E. Ya. Sherman Eur. Phys. J. Plus, 137 8 (2022) 884 Published online: 02 August 2022 DOI: 10.1140/epjp/s13360-022-03092-w