Gravitational microlensing of gamma-ray bursts at medium optical depth

Abstract

Gravitational lensing of a gamma-ray burst (GRB) by a single point mass will produce a second, delayed signal. Several authors have discussed using microlensed GRBs to probe a possible cosmological population of compact objects. We analyse a closely related phenomenon: the effect of microlensing by low to medium optical depth in compact objects on the averaged observed light curve of a sample of GRBs. We discuss the cumulative measured flux as a function of time resulting from delays caused by microlensing by cosmological compact objects. The time-scale and curvature of this function describe unique values for the compact object mass and optical depth. For GRBs with durations larger than the..