Sanjaye Ramgoolam



     String Theory,  Quantum Field Theory,  Quantum Gravity, Black Holes,
     Gauge Theory, Non-commutative   Geometry .

      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 :

  •    ``Non-commutative gravity from the ADS/CFT correspondence,''

  •      Antal Jevicki,  Sanjaye Ramgoolam ,  JHEP 9904:032,1999 ,  hep-th/9902059
  •    ``Finite N-effects in 4D super-Yang Mills theories and non-commutative spacetimes, ''

  •           P.M. Ho,  S. Ramgoolam, R. Tatar,         Nucl. Phys. B573 :364-376,2000,
  •   ``Non-commutative spheres and the ADS/CFT correspondence, ''

  •       A. Jevicki, M. Mihailescu, S. Ramgoolam  ,  JHEP 0010:008,2000 ,   hep-th/0006239

     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

  •  ``Hidden classical symmetry in quantum spaces at roots of unity : from q-sphere to fuzzy sphere ,''

  •      hep-th/0008186

       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.

  •      ``Fuzzy Spheres in AdS/CFT Correspondence and Holography from Noncommutativity,'' P.M.Ho and M. Li

  •      Nucl.Phys. B596 (2001) 259-272,    hep-th/0004072
  •        ``Matrix Theory, AdS/CFT and Higgs-Coulomb Equivalence,''  M. Berkooz and H. Verlinde,

  •      JHEP 9911 (1999) 037,  hep-th/9907100
  •       `` Invasion of the Giant Gravitons from Anti-de Sitter Space,''   J. Mc Greevy, L. Susskind, N. Toumbas,

  •          JHEP 0006 (2000) 008,   hep-th/0003075

      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

  • ``On the polarization of unstable D0-branes into noncommutative odd spheres, '' Z. Guralnik,   S. Ramgoolam ,

  •      JHEP 0102:032,2001,  hep-th/0101001
  •  ``On spherical harmonics for fuzzy spheres in diverse dimensions, ''    Nuc. Phys B 610 (2001)

  •          S. Ramgoolam, hep-th/0105006

    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 :

  • ``Branes, fluxes and duality in M(atrix) theory,'' O. Ganor, S. Ramgoolam,  W. Taylor,

  •    Nucl.Phys.B492:191-204,1997, hep-th/9611202
  • `` Torons and D-brane bound states,'' Z. Guralnik, S. Ramgoolam ,

  •      Nucl.Phys.B499:241-252,1997, hep-th/9611202
  •  `` From 0-branes to torons, '' Z. Guralnik, S. Ramgoolam,

  •      Nucl.Phys.B521:129-138,1998, hep-th/9708089
  •   `` Zero branes on a compact orbifold,'' S. Ramgoolam, D.  Waldram

  •        JHEP 9807:009,1998 , hep-th/9805191

     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.



    A ) String Theory and Particle Theory


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