Preprint typeset in JHEP style - HYPER VERSION LPTENS-05/08 hep-th/0502073 D-branes in Little String Theory∗ Dan Isra¨el1,2, Ari Pakman2 and Jan Troost1 1 Laboratoire de Physique Th´eorique de l’Ecole´ Normale Sup´erieure† 24, Rue Lhomond 75231 Paris Cedex 05, France 2 Racah Institute of Physics, The Hebrew University Jerusalem 91904, Israel E-mail:
[email protected],
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[email protected] Abstract: 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 functions giving the coupling of the closed string states with the D-branes and the spectrum of open strings are 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 which confirms the low-energy analysis in brane constructions, and that allows to go to higher energy scales. As an application we show the emergence of the beta-function of the N=2 gauge theory on D4-branes stretching between NS5-branes arXiv:hep-th/0502073v3 19 Jul 2005 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.