Rajesh Gopakumar


Research Summary:

In the last year I have continued my study of the relation between gauge theories and string theories.

In particular, my goal has been to answer the question of how exactly a gauge theory (in the large N limit) can reorganise itself into a dual closed string theory. Moreover, we would like to see if there is a systematic procedure which enables one to contruct the string theory starting from the field theory.

I have made some progress towards this end in the last year. In a couple of papers I have studied how free field theories in the large N limit can be reorganised into closed string theories. The answer comes via implementing the geometric idea of open-closed string duality on the field theory diagrams. To do so, a proper time parametrisation of field theory amplitudes is useful.

I show that this parametrised representation can be organised in a way which manifests the sum over Feynman graphs of the field theory as actually a sum over the two dimensional worldsheets underlying the dual closed string theory. In fact, this procedure also enables us to access the correlators of the two dimensional worldsheet theory of the string. This contains, in principle, all the information to construct the dual closed string theory. I have shown how the expected AdS structure of the closed string theory emerges from a study of two and three point functions.

At present I am engaged in developing this program further so as to be able to extract useful information about the dual string theory which might otherwise be inaccessible.


Publications:

  • R. Gopakumar, "From Free Fields to AdS", hep-th/0308184, (To appear in Phys. Rev. D .)

  • R. Gopakumar, "From Free Fields to AdS -II", hep-th/0402063, (To appear in Phys. Rev. D .)


Conference/Workshops Attended:

  • Amsterdam workshop on Quantum Gravity and String Theory, University of Amsterdam, Jun. 2003.

  • Second Crete Regional meeting on String Theory Kolymbari, Greece, Jun. 2003.

  • Strings 2003, Kyoto, Japan, July 2003.

  • IPM String School and Workshop 2003, Anzali, Iran, Sep. 2003.

  • Workshop on Geometry and Topology Inspired by Physics, University of Kochi, Dec. 2003.

  • National Workshop on String Theory, I.I.T. Kanpur, Dec. 2003.


Visits to other Institutes:

  • Harvard University, Cambridge, USA (March, 2003).

  • Rutgers University, USA (April, 2003).

  • Institute for Advanced Study, Princeton, USA, (April-June, 2003).

  • University of Amsterdam, The Netherlands, (June 2003, Apr. 2004).

  • I.I.T. Kanpur, (July 2003, Jan-Feb. 2004).

  • Saha Instt. of Nuclear Physics (Oct. 2003).

  • University of Paris VI, France (Mar. 2004).

  • Trinity College, Dublin, Ireland (Mar. 2004).


Invited Lectures/Seminars:

  • Seminar, IAS, Princeton, (May 2003).

  • Seminar, Amsterdam Workshop on String Theory, (Jun. 2003).

  • Lecture series at Second Crete Regional meeting on String Theory Kolymbari, Greece, (Jun. 2003).

  • Lecture Series at IPM String School and Workshop 2003, Anzali, Iran, (Sep. 2003).

  • Colloquium and Seminar, Saha Instt. of Nuclear Physics (Oct. 2003).

  • Colloquium, HRI, (Nov. 2003).

  • Lecture at Workshop on Geometry and Topology Inspired by Physics, University of Kochi, (Dec. 2003).

  • Lectures at National Workshop on String Theory, I.I.T. Kanpur, (Dec. 2003).

  • Seminar, University of Paris VI, France (Mar. 2004).

  • Public lectures on "Gauge Theory and Gravity" at Hamilton Institute March Meeting, Trinity College, Dublin, (Mar. 2004).


Other Activities:

Was one of the organisers of the "Eighth APCTP Winter School on String theory", Seoul, Korea, (Feb. 2003).

 



© Harish-Chandra Research Institute