Adding new hair to the 3-charge black ring

Motivated by the string theory analysis of arXiv:1108.6331, we construct a class of 1/8-BPS solutions of type IIB supergravity compactified on S^1 x T^4. In this duality frame our ansatz allows for a non-trivial NS-NS B-field which has been usually set to zero in previous studies of 1/8-BPS geometries. We provide a M-theory description of these new geometries and show that they can be interpreted as the lift of solutions of the N=2 5D supergravity with three vector multiplets and whose scalar manifold is the symmetric space SO(1,1) x (SO(1,2)/SO(2)). Finally we show that the non-minimal 5D black rings provide an explicit example of solutions falling in this ansatz. In particular we point out the existence of a black ring that has an extra dipole charge with respect to the solutions of the STU-model. In the near-horizon limit, this ring has an AdS_3 x S^3 geometry with the same radius as the one of the 3-charge black hole and thus its microstates should belong to the usual D1-D5 CFT.Comment: 18 page

Non-extremal superdescendants of the D1D5 CFT

We construct solutions of IIB supergravity dual to non-supersymmetric states of the D1D5 system. These solutions are constructed as perturbations carrying both left and right moving momentum around the maximally rotating D1D5 ground state at linear order. They are found by extending to the asymptotically flat region the geometry generated in the decoupling limit by the action of left and right R-currents on a known D1D5 microstate. The perturbations are regular everywhere and do not carry any global charge. We also study the near-extremal limit of the solutions and derive the first non-trivial correction to the extremal geometry.Comment: 25 page

Geometry of D1-D5-P bound states

Supersymmetric solutions of 6-d supergravity (with two translation symmetries) can be written as a hyperkahler base times a 2-D fiber. The subset of these solutions which correspond to true bound states of D1-D5-P charges give microstates of the 3-charge extremal black hole. To understand the characteristics shared by the bound states we decompose known bound state geometries into base-fiber form. The axial symmetry of the solutions make the base Gibbons-Hawking. We find the base to be actually `pseudo-hyperkahler': The signature changes from (4,0) to (0,4) across a hypersurface. 2-charge D1-D5 geometries are characterized by a `central curve' $S^1$; the analogue for 3-charge appears to be a hypersurface that for our metrics is an orbifold of $S^1\times S^3$.Comment: 20 pages, LaTeX; references adde

Dynamics of supertubes

We find the evolution of arbitrary excitations on 2-charge supertubes, by mapping the supertube to a string carrying traveling waves. We argue that when the coupling is increased from zero the energy of excitation leaks off to infinity, and when the coupling is increased still further a new set of long lived excitations emerge. We relate the excitations at small and large couplings to excitations in two different phases in the dual CFT. We conjecture a way to distinguish bound states from unbound states among 3-charge BPS geometries; this would identify black hole microstates among the complete set of BPS geometries.Comment: 50 pages, 3 figure

D1-D5-P microstates at the cap

The geometries describing D1-D5-P bound states in string theory have three regions: flat asymptotics, an anti-de Sitter throat, and a 'cap' region at the bottom of the throat. We identify the CFT description of a known class of supersymmetric D1-D5-P microstate geometries which describe degrees of freedom in the cap region. The class includes both regular solutions and solutions with conical defects, and generalizes configurations with known CFT descriptions: a parameter related to spectral flow in the CFT is generalized from integer to fractional values. We provide strong evidence for this identification by comparing the massless scalar excitation spectrum between gravity and CFT and finding exact agreement.Comment: 37 pages, 1 figure, v2: comment added, typos corrected, references adde

Entanglement entropy and D1-D5 geometries

http://dx.doi.org/10.1103/PhysRevD.90.066004Giusto, Stefano, and Rodolfo Russo. "Entanglement Entropy and D1-D5 geometries." Physical Review D 90.6 (2014): 066004

Perturbative superstrata

Issued under a Creative Commons Attribution LicenceS.G. has been partially supported by MIUR-PRIN contract 2009-KHZKRX, by the Padova University Project CPDA119349 and by INFN. R.R. has been partially supported by STFC Standard GrantST/J000469/1 “String Theory, Gauge Theory and Duality”

Hemostasis in uncontrolled esophageal variceal bleeding by self-expanding metal stents. A systematic review

Aim: The aim of this systematic review was to evaluate the current reported efficacy and the mortality rate of SEMS treatment in uncontrolled bleeding patients. Background: Esophageal variceal bleeding (EVB) represents a life threatening pathology. Despite the adequate pharmacologic and endoscopic treatment, continuous or recurrent bleeding, named as uncontrolled bleeding, occurs in 10-20% of cases. A new removable, covered, and self-expanding metal stent (SEMS) was proposed to control the variceal bleeding. Materials and methods: The study was conducted according to the PRISMA statement. Studies were identified by searching MEDLINE (1989-present) and SCOPUS (1989-present) databases. The last search was run on 01 July 2015. Results: Nine studies (period range=2002-2015) met the inclusion criteria and were included in quantitative analysis. High rate of SEMS efficacy in controling acute bleeding was observed, with a reported percentage ranging from 77.7 to 100%. In 10% to 20% of patients, re-bleeding occurred with SEMS in situ. Stent deployment was successful in 77.8% to 100% of patients while 11 to 36.5% of patients experienced stent migration. Conclusion: SEMS could be effective and safe in control EVB and can be proposed as a reliable option to ballon tamponed for patient stabilization and as a bridging to other therapeutic approach. Keywords: Nonselective β-blockers, TIPSS, Endoscopic band ligation, Uncontrolled bleeding, Selfexpanding metal stent

Branes wrapping Black Holes

We examine the dynamics of extended branes, carrying lower dimensional brane charges, wrapping black holes and black hole microstates in M and Type II string theory. We show that they have a universal dispersion relation typical of threshold bound states with a total energy equal to the sum of the contributions from the charges. In near-horizon geometries of black holes, these are BPS states, and the dispersion relation follows from supersymmetry as well as properties of the conformal algebra. However they break all supersymmetries of the full asymptotic geometries of black holes and microstates. We comment on a recent proposal which uses these states to explain black hole entropy.Comment: 41 pages, 2 figures;v2: references adde

The black hole behind the cut

We study the analytic structure of the heavy-heavy-light-light holographic correlators in the supergravity approximation of the AdS$_3 \times S^3$/CFT$_2$ duality. As an explicit example, we derive the correlator where the heavy operator is a classical microstate of the 5D supersymmetric black hole and its dual geometry interpolates as a function of a continuous parameter between global AdS$_3$ and the extremal BTZ black hole. The simplest perturbation of this interpolating geometry by a light field is described by the Heun equation and we exploit the relation of its connection coefficients to the Liouville CFT to analytically compute the correlator in the two limits, focusing in particular on the black hole regime. In this limit we find that the real poles of the correlator become dense and can be approximated by a cut. We show that, when the charges of the heavy state are in the black hole regime, the discontinuity across the cut has complex poles corresponding to the quasi-normal modes of BTZ. This behaviour is qualitatively similar to what is expected for the large central charge limit of a typical black hole microstateComment: 59 pages, 1 figur