D-Branes in NS5-branes and fundamental strings background

by Dan Israel (Hebrew University Jerusalem)

Tuesday 12 Jul 2005, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

We analyze in detail the D-branes in the near-horizon limit of NS5-branes on a circle, the holographic dual of little string theory in a double scaling limit. We emphasize their geometry in the background of the NS5-branes and show the relation with D-branes in coset models. The exact one-point function giving the coupling of the closed string states with the D-branes and the spectrum of open strings is computed. Using these results, we analyze several aspects of Hanany-Witten setups, using exact CFT analysis. In particular we identify the open string spectrum on the D-branes stretched between NS5-branes. As an application we show the emergence of the beta-function of the N=2 gauge theory on D4-branes stretching between NS5-branes from the boundary states describing the D4-branes. We also speculate on the possibility of getting a matrix model description of little string theory from the effective theory on the D1-branes. By considering D3-branes orthogonal to the NS5-branes we find a CFT incarnation of the Hanany-Witten effect of anomalous creation of D-branes. If time permits, we will briefly describe the D-branes in AdS3, the NS5-fundamental strings background.