My recent works have focused on two general areas.
One is ``Applications of non-commutative manifolds in string theory.''
More specifically I have worked on non-commutative spheres,
with two main classes of applications. The first is to understand
the ``stringy exclusion
principle'' from a spacetime point of view.
A selection of my first papers in this area were :
In the course of these investigations we were lead
to wonder about the relations
between fuzzy spheres and q-spheres, and some investigations
along these lines were
reported in
A small sample among many other interesting papers which
deal
with closely
related issues is given below. The paper on ``giant gravitons''
in particular may,
in the long run,
be quite central to our whole perception of what string theory is
and how it relates to gravity.
More related papers
can be accessed by looking up the citation lists of the papers above
or below.
The second, related and more
general, application of non-commutative
spheres involves the
fascinating field of brane polarization effects,
where simple facts about
D-brane actions and their spacetime interpretation conspire
to give a grandiose string
theory realization of the lowly :) dielectric effect .
Two papers I have written
along these lines
are
Here is an artist's impression of
a fuzzy odd sphere :)
Work on a better artistic impression is under progress . Suggestions are welcome.
The area of brane polarization effects is very large, and a coherent
picture
of what it is telling us about spacetime remains to be formulated.
Works
in this area can be accessed by looking up citations of the original
paper
which is linked above.
One of my more speculative efforts
involves an application of the stringy spacetime
uncertainty relation,
an idea closely related to spacetime non-commutativity,
to cosmology :
``Stringy space-time uncertainty
as an alternative to inflation,''
J.Gu, P.M Ho, S. Ramgoolam, hep-th/0101058
My other general
area of interest has been `` Connections between
gauge theory
and spacetime physics in string theory .'' Key papers
in this area
are the ones by Witten,
BFSS and Maldacena .
A sample of
my papers in this area are :
The toron-D-brane connection
has been relevant to some interesting applications
to black holes, and to brane constructions
of the Standard Model.
My other areas of interest have been : D-branes
and cohomology, D-branes and
Einstein action on Worldvolume, Monopoles
without adjoint matter,
SL(2,R) current algebra, c=1 Matrix model,
quantum groups,
string theory of 2D Yang Mills, scattering in Matrix
Theory,
correlation functions in orbifold CFT.
A complete list of my
publications can be found from the SLAC spires database,
which lists a huge number
of particle physics papers.