  We compute AC electrical transport at quantum Hall critical points, as
modeled by intersecting branes and gauge/gravity duality. We compare our
results with a previous field theory computation by Sachdev, and find
unexpectedly good agreement. We also give general results for DC Hall and
longitudinal conductivities valid for a wide class of quantum Hall transitions,
as well as (semi)analytical results for AC quantities in special limits. Our
results exhibit a surprising degree of universality; for example, we find that
the high frequency behavior, including subleading behavior, is identical for
our entire class of theories.
