Searching for primordial black holes with the VERITAS gamma-ray experiment

Primordial black holes (PBHs) could have been formed in the early Universe from gravitational collapse of matter-energy density fluctuations, collapsing cosmic strings or phase transitions. Setting a limit on the number density of PBHs is important for cosmology, particle physics and quantum gravity. According to some theoretical models, PBHs evaporate and could produce bursts of very-high-energy (VHE; E > 100 GeV) gamma rays which could be seen by detectors on Earth. We present the results from a search in 700 hours of VERITAS data for evidence of gamma-ray bursts due to evaporating PBHs. A new constraint on the number density of PBHs is derived by comparing the VERITAS data with a model prediction.