> While an M⊕ object is too light to be an astrophysical black hole formed by stellar collapse, PBHs arise from over densities in the early universe [15, 16] an

> While an M⊕ object is too light to be an astrophysical black hole formed by stellar collapse, PBHs arise from over densities in the early universe [15, 16] and as a result can be substantially lighter than M . Normally black holes do have at least the mass of ~1.4 times our sun because they are formed by stellar collapse. That is why here they are considering Primordial Black Holes which a) formed differently and b) radiated some of their mass away