  Gamma-ray bursts (GRBs) are detectable out to very large distances and as
such are potentially powerful cosmological probes. Historically, the angular
distribution of GRBs provided important information about their origin and
physical properties. As a general population, GRBs are distributed
isotropically across the sky. However, there are published reports that once
binned by duration or redshift, GRBs display significant clustering. We have
studied the redshift- and duration-dependent clustering of GRBs using proximity
measures and kernel density estimation. Utilizing bursts detected by BATSE,
Fermi/GBM and Swift/BAT, we found marginal evidence for clustering in very
short duration GRBs lasting less than 100 ms. Our analysis provides little
evidence for significant redshift-dependent clustering of GRBs.
