HEP/Astro Seminar -- Monday, 27 November 2000

Marginal deformation and creation of codimension ≥ 2 solitons on brane-antibrane pair

Jaydeep Majumder, (Harish-Chandra Inst, India)

Abstract

After the discovery of the mechanism of tachyon condensation by Sen, Witten showed that the K-theory is the correct mathematical framework for describing the phenomena of getting all the lower dimensional BPS and non-BPS D-branes by condensing tachyonic solitons of various codimensions on a bunch of D9-D9-pairs (in type IIB theory) or a bunch of non-BPS D9-branes (in type IIA theory). The exact conformal field theory describing a codimension one tachyonic soliton was already known. For codimension = q > 1 solitons, it was conjectured that such a soliton on a Dp-Dp-brane pair represents a D(p-q)-brane. Witten gave an ansatz for the higher codimension solitions in his K-theory paper. In the first part of my talk, I shall establish these results explicitly for codimension two solitons (vortex/antivortex) by first identifying a series of marginal deformations which create the vortex-antivortex pair on the brane-antibrane system and then showing that under this series of marginal deformations the original D-brane-anti-D-brane system becomes a D-brane-anti-D-brane system with 2 lower dimension.

In the second part of my talk, I shall apply this method to a particular example. I shall consider a sytem containing a pair of non-BPS D-strings of type IIA string theory on a Calabi-Yau 3-fold orbifold with (h^(1,1),h^(1,2)) = (11, 11). After finding the region of stability in the moduli space for this system, I shall show that the system decays to a pair of non-BPS D3-branes.

References

"Vortex pair creation on brane-antibrane pair via marginal deformation," Jaydeep Majumder and Ashoke Sen (Harish-Chandra Inst, India). hep-th/0003124

"Non-BPS D-branes on a Calabi-Yau orbifold," Jaydeep Majumder and Ashoke Sen (Harish-Chandra Inst, India). hep-th/0007158

12:30pm, Smith Lab 1094