Relation between the dark matter surface density and the core radius of dark matter haloes (top). Relation between the core radius and the virial mass of dark matter haloes (bottom). The purple circles in both panelsrepresent the simulated FDM haloes, and the empty squares represent the properties of dark matter haloes hosting observed LSB dwarf galaxies (Di Paolo & Salucci 2020). In addition, the dashed black lines correspond to the result of the URC method presented in Salucci et al. (2007).