David D. K. Chow

Dyonic AdS black holes in maximal gauged supergravity

We present two new classes of dyonic anti-de Sitter black hole solutions of four-dimensional maximal N=8, SO(8) gauged supergravity. They are (1) static black holes of N=2, U(1)4 gauged supergravity with four electric and four magnetic charges, with spherical, planar or hyperbolic horizons; and (2) rotating black holes of N=2, U(1)2 gauged supergravity with two electric and two magnetic charges. We study their thermodynamics, and point out that the formulation of a consistent thermodynamics for dyonic anti-de Sitter black holes is dependent on the existence of boundary conditions for the gauge fields. We identify several distinct classes of boundary conditions for gauge fields in U(1)4 supergravity. We study a general family of metrics containing the rotating solutions, and find Killing-Yano tensors with torsion in two conformal frames, which underlie separability.

Classification of solutions in topologically massive gravity

We study exact solutions of three-dimensional gravity with a cosmological constant and a gravitational Chern–Simons term: the theory known as topologically massive gravity. After reviewing the algebraic classification, we show that if a solution has curvature of algebraic type D, then it is biaxially squashed AdS3. Applying the classification, we provide a comprehensive review of the literature, showing that most known solutions are locally equivalent to biaxially squashed AdS3 or to AdS pp-waves.

Black holes in N=8 supergravity from SO(4,4) hidden symmetries

We detail the construction of the most general asymptotically flat, stationary, rotating, nonextremal, dyonic black hole of the four-dimensional N = 2 supergravity coupled to 3 vector multiplets that describes the S T U model. It generates through U dualities the most general asymptotically flat, stationary black hole of N = 8 supergravity. We develop the solution generating technique based on SO ( 4 , 4 ) / SL ( 2 , R ) 4 coset model symmetries, with an emphasis on the 4-fold permutation symmetry of the gauge fields. We indicate how previously known nonextremal and extremal solutions of the S T U model are recovered as limiting cases. Several properties of the general black hole solution are discussed, including its thermodynamics, the quadratic mass formula, the Bogomolny-Prasad-Sommerfield limit, the slow and fast extremal rotating limits, its properties in regards to the Kerr/conformal field theory correspondence, its Killing tensors and the separability of geodesic motion and probe scalars.

Kundt spacetimes as solutions of topologically massive gravity

We obtain new solutions of topologically massive gravity. We find the general Kundt solutions, which in three dimensions are spacetimes admitting an expansion-free null geodesic congruence. The solutions are generically of algebraic type II, but special cases are types III, N or D. Those of type D are the known spacelike-squashed AdS3 solutions and of type N are the known AdS pp-waves or new solutions. Those of types II and III are the first known solutions of these algebraic types. We present explicitly the Kundt solutions that are constant scalar invariant (CSI) spacetimes, for which all scalar polynomial curvature invariants are constant, whereas for the general case, we reduce the field equations to a series of ordinary differential equations. The CSI solutions of types II and III are deformations of spacelike-squashed AdS3 and the round AdS3, respectively.

Single-charge rotating black holes in four-dimensional gauged supergravity

We consider four-dimensional U(1)4 gauged supergravity, and obtain asymptotically AdS4, non-extremal, charged, rotating black holes with one non-zero U(1) charge. The thermodynamic quantities are computed. We obtain a generalization that includes a NUT parameter. The general solution has a discrete symmetry involving inversion of the rotation parameter, and has a string frame metric that admits a rank-2 Killing–Stackel tensor.

Charged rotating black holes in six-dimensional gauged supergravity

We obtain non-extremal charged rotating black holes in six-dimensional SU(2) gauged supergravity with two independent angular momenta and one U(1) charge. These include supersymmetric black holes without naked closed timelike curves.

Higher-dimensional lifts of Killing–Yano forms with torsion

Using a Kaluza–Klein-type lift, it is shown how Killing–Yano forms with torsion can remain symmetries of a higher-dimensional geometry, subject to an algebraic condition between the Kaluza–Klein field strength and the Killing–Yano form. The lift condition’s significance is highlighted, and is satisfied by examples of black holes in supergravity.