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Supersymmetric Probes in a Rotating 5D Attractor

Wei Li, Andrew StromingerSubjects: Physics >> The Physics of Elementary Particles and Fields

Supersymmetric zero-brane and one-brane probes in the squashed AdS2譙3 near-horizon geometry of the BMPV black hole are studied. Supersymmetric zero-brane probes stabilized by orbital angular momentum on the S3 are found and shown to saturate a BPS bound. We also find supersymmetric one-brane probes which have momentum and winding around a U(1)L譛(1)R torus in the S3 and in some cases are static. |

Non-Supersymmetric Attractor Flow in Symmetric Spaces

Davide Gaiotto, Wei Li, Megha PadiSubjects: Physics >> The Physics of Elementary Particles and Fields

We derive extremal black hole solutions for a variety of four dimensional models which, after Kaluza-Klein reduction, admit a description in terms of 3D gravity coupled to a sigma model with symmetric target space. The solutions are in correspondence with certain nilpotent generators of the isometry group. In particular, we provide the exact solution for a non-BPS black hole with generic charges and asymptotic moduli in N=2 supergravity coupled to one vector multiplet. Multi-centered solutions can also be generated with this technique. It is shown that the non-supersymmetric solutions lack the intricate moduli space of bound configurations that are typical of the supersymmetric case. |

Non-Supersymmetric Attractors in Symmetric Coset Spaces

Wei LiSubjects: Physics >> The Physics of Elementary Particles and Fields

We present a method of constructing generic single-centered and multi-centered extremal black hole solutions in a large class of 4D N=2 supergravities coupled to vector-multiplets with cubic prepotentials. The method is applicable to models for which the 3D moduli spaces obtained via c*-map are symmetric coset spaces. The attractor solutions are generated by certain nilpotent elements in the coset algebra. We present explicit computations in 4D N=2 supergravity coupled to one vector-multiplet, whose 3D moduli space is the symmetric coset space G_{2(2)}/SL(2,R)^2. The non-supersymmetric multi-centered black holes in this model are found to lack the intricate moduli space of bound configurations that are typical of the supersymmetric case. |

Comment on "Cosmological Topological Massive Gravitons and Photons"

Wei Li, Wei Song, Andrew StromingerSubjects: Physics >> The Physics of Elementary Particles and Fields

In a recent paper (arXiv: 0801.4566) it was shown that all global energy eigenstates of asymptotically AdS3 chiral gravity have non-negative energy at the linearized level. This result was questioned (arXiv: 0803.3998) by Carlip, Deser, Waldron and Wise (CDWW), who work on the Poincare patch. They exhibit a linearized solution of chiral gravity and claim that it has negative energy and is smooth at the boundary. We show that the solution of CDWW is smooth only on that part of the boundary of AdS3 included in the Poincare patch. Extended to global AdS3, it is divergent at the boundary point not included in the Poincare patch. Hence it is consistent with the results of (arXiv: 0801.4566). |

Subjects: Physics >> The Physics of Elementary Particles and Fields

Three dimensional topologically massive gravity (TMG) with a negative cosmological constant -\ell^{-2} and positive Newton constant G admits an AdS_3 vacuum solution for any value of the graviton mass \mu. These are all known to be perturbatively unstable except at the recently explored chiral point \mu\ell=1. However we show herein that for every value of \mu\ell< 3 there are two other (potentially stable) vacuum solutions given by SL(2,R)x U(1)-invariant warped AdS_3 geometries, with a timelike or spacelike U(1) isometry. Critical behavior occurs at \mu\ell=3, where the warping transitions from a stretching to a squashing, and there are a pair of warped solutions with a null U(1) isometry. For \mu\ell>3, there are known warped black hole solutions which are asymptotic to warped AdS_3. We show that these black holes are discrete quotients of warped AdS_3 just as BTZ black holes are discrete quotients of ordinary AdS_3. Moreover new solutions of this type, relevant to any theory with warped AdS_3 solutions, are exhibited. Finally we note that the black hole thermodynamics is consistent with the hypothesis that, for \mu\ell>3, the warped AdS_3 ground state of TMG is holographically dual to a 2D boundary CFT with central charges c_R={15(\mu\ell)^2+81\over G\mu((\mu\ell)^2+27)} and c_L={12 \mu\ell^2\over G((\mu\ell)^2+27)}. |

Chiral Gravity in Three Dimensions

Wei Li, Wei Song, Andrew StromingerSubjects: Physics >> The Physics of Elementary Particles and Fields

Three dimensional Einstein gravity with negative cosmological constant -1/\ell^2 deformed by a gravitational Chern-Simons action with coefficient 1/\mu is studied in an asymptotically AdS_3 spacetime. It is argued to violate unitary or positivity for generic \mu due to negative-energy massive gravitons. However at the critical value \mu\ell=1, the massive gravitons disappear and BTZ black holes all have mass and angular momentum related by \ell M=J. The corresponding chiral quantum theory of gravity is conjectured to exist and be dual to a purely right-moving boundary CFT with central charges (c_L,c_R)=(0,3\ell /G). |

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