Primordial black holes may trigger some white dwarf explosions and leave measurable signatures in the Milky Way’s chemistry. Some Type Ia supernovae may begin with an invisible intruder passing through a white dwarf. Primordial black holes (PBH) are hypothetical remnants of the early universe that may have formed from fluctuations in matter during cosmic inflation. Their results indicated that a non-zero fraction of Type Ia supernovae triggered by primordial black holes is needed to explain a chemical abundance trend observed among Milky Way stars. Reference: “Primordial Black Hole Triggered Type Ia Supernovae.