String theory of supertubes

Abstract

String theory on AdS 3 backgrounds arises as an IR limit of Little String Theory on NS5-branes. A wide variety of holographic RG flows from the fivebrane theory in the UV to (orbifolds of) AdS 3 in the IR is amenable to exact treatment in worldsheet string theory as a class of null-gauged WZW models. The condensate of stringy winding operators which resolves the near-source structure of fivebranes on the Coulomb branch plays a crucial role in AdS 3 , revealing stringy structure invisible to the supergravity approximation. The D-brane sector contains precursors of the long strings which dominate black hole entropy in the dual spacetime CFT. D-branes 40-i -7 Discussion 44 A Current algebra properties 47 A.1 SU (2) 47 A.2 SL(2, R) 49 5 Note that the natural coordinates for the branes exclude the region r BTZ < r − [13].

A solvable irrelevant deformation of AdS3/CFT2

“…Systems of fivebranes in motion are described by modifying the null current to involve the time translation generator [21]. And, recently it has been shown [22] that some of the Ramond ground states of the string-fivebrane system can be described by adding the null translation generator in IR 1,1 (more precisely IR × S 1 ) to the null generator J 3 − K 3 mentioned above. Other closely related cosets give rise to black holes (see e.g.…”

Little strings, long strings, and fuzzballs

“…and gauges a pair of null isometries so that the physical target spacetime geometry is 9+1 dimensional [66]. Roughly, the first factor in G lies largely transverse to the fivebranes but has 5+1 rather than 4+0 dimensions; the role of the gauging is to eliminate the unwanted directions.…”

“…We then specialize the discussion to group manifolds G, using the symmetry analysis of [73,77,82,83,[85][86][87][88] and especially the work of Quella and Schomerus [89][90][91] to determine both the shape of the brane in simple examples as well as the two-form ω 2 = B + F that solves the DBI equations of motion. Section 4 reviews the results of [66], showing how the choice of gauged null isometries in (1.8) yields the fivebrane backgrounds of interest. Various D-branes in the SL(2, R) and SU (2) WZW models are then reviewed in Section 5.…”

Correlation functions in the D1-D5 orbifold CFT

“…Early discussions of (non-generic) microstates for macroscopic black holes can be found in [18][19][20][21][22][23][24][25]. Recent constructions of microstates illustrate more generic features, using concepts such as superstrata, see for example [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]; there is ongoing study of what fraction of the black hole microstates such constructions can represent.…”