Evidence for Primordial Black Hole Final Evaporation: Swift, BATSE and KONUS and Comparisons of VSGRBs and Observations of VSB That Have PBH Time Signatures

Abstract

More than a decade ago we identified a class of VSGRB (T90 < 100 ms) as having unusual properties: (1) galactic position asymmetry, (2) very hard gamma spectrum, (3) possible evidence for galactic origin of these events. We now study the recent Swift data and show that a VSGRB enhancement consistent BATSE and KONUS exists. We estimate that this is now a total 4.5sigma observation. We then study the VSB for evidence of the time structure expected for PBH evaporation. Several of the events show the general time structure expected for PBH evaporation. If correct, then PBH must exist in this galaxy. Since even large detectors like BATSE record only a few VSB per year the density of PBH can still be very small and it is hard to predict a rate for the Fermi spacecraft LAT.