Black Five-Branes and Fluxbranes on Gravitational Instantons

We apply a U-duality based solution-generating technique to construct supergravity solutions which describe nonextremal D5-branes and fluxbranes on various gravitational instantons. This includes an F7-brane wrapped on a sphere, which remains weakly-coupled in the asymptotic region. We construct various superpositions of nonextremal D5-branes and fluxbranes that have angular momentum fixed by the parameters associated with their mass and two magnetic charges.Comment: 14 pages, added references, an additional commen

Warped Resolved \u3cem\u3eL\u3csup\u3ea,b,c\u3c/sup\u3e\u3c/em\u3e Cones

We construct supergravity solutions describing a stack of D3-branes localized at a point on a blown-up cycle of a resolved La,b,c cone. The geometry flows from AdS5 × La,b,c to AdS5 × S5 × Zk. The corresponding quiver gauge theory undergoes a renormalization group flow between two superconformal fixed points, which leads to semi-infinite chains of flows between the various La;b;c fixed points. The general system is described by a triplet of Heun equations, which can each be solved by an expansion with a three-term recursion relation, though there are closed-form solutions for certain cases. This enables us to read off the operators that acquire nonzero vacuum expectation values as the quiver gauge theory flows away from a fixed point

Strongly-Coupled Quarks and Colorful Black Holes

We use the AdS/CFT correspondence to study the behavior of strongly-coupled quarks in a black hole background. The supergravity background consists of a six-dimensional Schwarzschild-black string AdS soliton, for which the bulk horizon extends from the AdS boundary down to an infra-red floor. By going to higher energy scales, the regime of validity of the classical supergravity background can be extended closer to the singularity than might be expected from the four-dimensional perspective. Small black holes potentially created by the Large Hadron Collider could typically carry color charges inherited from their parton progenitors. The dynamics of quarks near such a black hole depends on the curved spacetime geometry as well as the strong interaction with the color-charged black hole. We study the resulting behavior of quarks and compute the rate at which a quark rotating around the black hole loses energy. We also investigate how the interaction between a quark and an antiquark is altered by the presence of the black hole, which results in a screening length.Comment: Proceedings of the DPF-2011 Conference, 8 pages, 5 figures, added reference

Penrose limits of non-standard brane intersections

The non-standard intersection of two 5-branes and a string can give rise to AdS3 × S3 × S3 × S1. We consider the Penrose limit of this geometry and study the supersymmetry of the resulting pp-wave solution. There is a one-parameter family of Penrose limits associated with the orthogonal rotation of the two foliating circles within the two 3-spheres. Supernumerary Killing spinors arise only when the rotation angle is 45°, for which case we obtain the corresponding light-cone string action that has linearly-realized supersymmetry. We also obtain Penrose limits of other non-standard intersections that give rise to the product of AdS3 or AdS2 and 2-spheres. The resulting pp-waves are supported by multiple constant field strengths.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49207/2/q21512.pd

Brane Resolution Through Fibration

We consider p-branes with one or more circular directions fibered over the transverse space. The fibration, in conjunction with the transverse space having a blown-up cycle, enables these p-brane solutions to be completely regular. Some such circularly-wrapped D3-brane solutions describe flows from SU(N)^3 N=2 theory, F_0 theory, as well as an infinite family of superconformal quiver gauge theories, down to three-dimensional field theories. We discuss the operators that are turned on away from the UV fixed points. Similarly, there are wrapped M2-brane solutions which describe smooth flows from known three-dimensional supersymmetric Chern-Simons matter theories, such as ABJM theory. We also consider p-brane solutions on gravitational instantons, and discuss various ways in which U-duality can be applied to yield other non-singular solutions.Comment: 35 pages, additional referenc

AdS and Lifshitz Black Holes in Conformal and Einstein-Weyl Gravities

We study black hole solutions in extended gravities with higher-order curvature terms, including conformal and Einstein-Weyl gravities. In addition to the usual AdS vacuum, the theories admit Lifshitz and Schr\"odinger vacua. The AdS black hole in conformal gravity contains an additional parameter over and above the mass, which may be interpreted as a massive spin-2 hair. By considering the first law of thermodynamics, we find that it is necessary to introduce an associated additional intensive/extensive pair of thermodynamic quantities. We also obtain new Liftshitz black holes in conformal gravity and study their thermodynamics. We use a numerical approach to demonstrate that AdS black holes beyond the Schwarzschild-AdS solution exist in Einstein-Weyl gravity. We also demonstrate the existence of asymptotically Lifshitz black holes in Einstein-Weyl gravity. The Lifshitz black holes arise at the boundary of the parameter ranges for the AdS black holes. Outside the range, the solutions develop naked singularities. The asymptotically AdS and Lifshitz black holes provide an interesting phase transition, in the corresponding boundary field theory, from a relativistic Lorentzian system to a non-relativistic Lifshitz system.Comment: typos corrected, references adde

Open Wilson Lines and Chiral Condensates in Thermal Holographic QCD

We investigate various aspects of a proposal by Aharony and Kutasov arXiv:0803.3547 [hep-th] for the gravity dual of an open Wilson line in the Sakai-Sugimoto model or its non-compact version. In particular, we use their proposal to determine the effect of finite temperature, as well as background electric and magnetic fields, on the chiral symmetry breaking order parameter. We also generalize their prescription to more complicated worldsheets and identify the operators dual to such worldsheets.Comment: 45 pages, 18 figures; added reference