The Search for Primordial Black Holes Using Very Short Gamma Ray Bursts

We show the locations of the SWIFT short hard bursts (SHB) with afterglows on the galactic map and compare with the VSB BATSE events. As we have pointed out before, there is an excess of events in the galactic map of BATSE VSB events. We not that none of VSB SWIFT era events fall into this cluster. More SWIFT events are needed to check this claim. We also report a new study with KONUS data of the VSB sample with an average energy above 90 keV showing a clear excess of events below 100 ms duration (T90) that have large mean energy protons. We suggest that VSB themselves consist of two subclasses: a fraction of events have peculiar distribution properties and have no detectable counterparts, as might be expected for exotic sources such as primordial black holes. We show how GLAST could add key new information to the study of VSB bursts and could help test the black hole concept.