Non-geometric String Backgrounds and Worldsheet Algebras

Using worldsheet Hamiltonian methods we derive a charge algebra which generalizes the Courant bracket to include fluxes of general index type. This is achieved by coupling a bi-vector to the Hamiltonian of the Polyakov model. This bracket is useful to describe so-called non-geometric backgrounds and has been discussed in the mathematics literature by Dmitry Roytenberg.Comment: 18 page

BPS Black Hole Horizons in N=2 Gauged Supergravity

We study static BPS black hole horizons in four dimensional N=2 gauged supergravity coupled to $n_v$-vector multiplets and with an arbitrary cubic prepotential. We work in a symplectically covariant formalism which allows for both electric and magnetic gauging parameters as well as dyonic background charges and obtain the general solution to the BPS equations for horizons of the form $AdS_2\times \Sigma_g$. In particular this means we solve for the scalar fields as well as the metric of these black holes as a function of the gauging parameters and background charges. When the special Kahler manifold is a symmetric space, our solution is completely explicit and the entropy is related to the familiar quartic invariant. For more general models our solution is implicit up to a set of holomorphic quadratic equations. For particular models which have known embeddings in M-theory, we derive new horizon geometries with dyonic charges and numerically construct black hole solutions. These correspond to M2-branes wrapped on a Riemann surface in a local Calabi-Yau five-fold with internal spin.Comment: 17 pages, 2 figures. v2 refs adde

Missing Mirrors: Type IIA Supergravity on the Resolved Conifold

We consider massive IIA supergravity on the resolved conifold with $SU(2)_L^2\times U(1)_R$ symmetry and $\N=1$ supersymmetry. A one dimensional family of such regular solutions was found by Brandhuber and we propose this to be the mirror to one dimension of the moduli space of IIB solutions on the deformed conifold found by Butti et al. This family provides a description of the geometric transition in terms of a smooth family of flux backgrounds. The remaining dimension of the moduli space of Butti et al contains the baryonic branch of Klebanov-Strassler and we propose that the mirror of this is either some stringy resolution of a family of singular solutions found here or must be entirely non-geometric.Comment: 27 pages, 2 figures

Abelian Hypermultiplet Gaugings and BPS Vacua in N = 2 Supergravity

We analyze the gauging of Abelian isometries on the hypermultiplet scalar manifolds of N = 2 supergravity in four dimensions. This involves a study of symmetric special quaternionic-K\"ahler manifolds, building on the work of de Wit and Van Proeyen. In particular we compute the general set of Killing prepotentials and associated compensators for these manifolds manifolds. This allows us to glean new insights about AdS 4 vacua which preserve the full N = 2 supersymmetry as well as BPS static black hole horizons.Comment: 22 p. (+ 14 app.); v2: published version, fix minor typos and Killing prepotential expression

q-Identities and affinized projective varieties, II. Flag varieties

In a previous paper we defined the concept of an affinized projective variety and its associated Hilbert series. We computed the Hilbert series for varieties associated to quadratic monomial ideals. In this paper we show how to apply these results to affinized flag varieties. We discuss various examples and conjecture a correspondence between the Hilbert series of an affinized flag variety and a modified Hall-Littlewood polynomial. We briefly discuss the application of these results to quasi-particle character formulas for affine Lie algebra modules.Comment: AMSTeX, 25 pages, 3 figure

AdS Black Holes from Duality in Gauged Supergravity

We study and utilize duality transformations in a particular STU-model of four dimensional gauged supergravity. This model is a truncation of the de Wit-Nicolai N=8 theory and as such has a lift to eleven-dimensional supergravity on the seven-sphere. Our duality group is $U(1)^3$ and while it can be applied to any solution of this theory, we consider the known asymptotically AdS$_4$, supersymmetric black holes and focus on duality transformations which preserve supersymmetry. For static black holes we generalize the supersymmetric solutions of Cacciatori and Klemm from three magnetic charges to include two additional electric charges and argue that this is co-dimension one in the full space of supersymmetric static black holes in the STU-model. These new static black holes have nontrivial profiles for axions. For rotating black holes, we generalize the known two-parameter supersymmetric solution to include an additional parameter which represents scalar hair. When lifted to M-theory, these black holes correspond to the near horizon geometry of a stack of BPS rotating M2-branes, spinning on an $S^7$ which is fibered non-trivially over a Riemann surface.Comment: 21 page

Tensor Models for Black Hole Probes

The infrared dynamics of the SYK model, as well as its associated tensor models, exhibit some of the non trivial features expected of a holographic dual of near extremal black holes. These include developing certain symmetries of the near horizon geometry and exhibiting maximal chaos. In this paper we present a generalization of these tensor models to include fields with fewer tensor indices and which can be thought of as describing probes in a black hole background. In large $N$ limit, dynamics of the original model remain unaffected by the probe fields and the four point functions of the probe fields exhibit maximal chaos, a non trivial feature expected of a black hole probe. Interestingly probe primaries have the same dimensions as primaries of the original fields.Comment: 32 pages, 12 figure

Non-Relativistic Solutions of N=2 Gauged Supergravity

We find infinite families of supersymmetric solutions of four dimensional, N=2 gauged supergravity with Lifshitz, Schrodinger and also AdS symmetries. We focus on the canonical example of a single hypermultiplet and a single vector multiplet and find that the spectrum of solutions depends crucially on whether the gaugings are electric or magnetic but to a far milder extent on the strength of the gaugings. For purely electric or purely magnetic gaugings we generically find Lifshitz solutions, while for a mixed gauging we find Schrodinger and AdS solutions. For some of the gaugings the theory has a known lift to string/M-theory thus giving a higher dimensional embedding of our solutions.Comment: 27 pages, v2 refs added, comments regarding string embeddings altered, cleaner discussion of the scaling parameter for Schrodinger solutions; v3 published version, refs adde

Punctures from Probe M5-Branes and N=1 Superconformal Field Theories

We study probe M5-branes in N=1 AdS5 solutions of M-theory that arise from M5-branes wrapped on a Riemann surface. Using the BPS condition from kappa-symmetry, we classify supersymmetric probe M5-branes that extend along all of AdS5 and intersect the Riemann surface at points. These can be viewed as punctures in the dual N=1 superconformal field theories. We find M5-branes that correspond to the two types of simple punctures previously studied in field theory. In addition, when the central charge is rational, we find a new class of M5-branes with a moduli space that includes two internal dimensions in addition to the Riemann surface. These new M5-branes have the essential characteristic of fractional branes, in that a single one at a generic point of its moduli space becomes multiple M5-branes at special points.Comment: 29 pages, 9 figure