My interests: My general interest is in strongly correlated
systems - and here quantum criticality is providing a useful framework
for a wide variety of such systems. One aspect of my work is
concerned with quantum criticality in oxide metals like the ruthenates
which sometimes offer a new perspective on the issues we face in
understanding heavy fermion quantum criticality. Recently I've been
concerned with issues of transport near a quantum critical point where
the collapse of an energy scale at the QCP can lead to rich
transport behaviour.

My questions (well, some of them):
(1) Given the theoretical problems with Hertz Millis theory
(e.g. integrating out the fermions), why does it ever appear to work?
(2) Experimentally some quantum critical systems appear to be above, and
some below their upper critical dimensions. Again, can we develop a
framework which accounts for this---and is predictive?
(3) It is tempting to attribute all non-Fermi liquid metallic behaviour
to proximity to a quantum critical point. Is this the only route to a
non-Fermi liquid in dimensions greater than one?