arXiv subjects

Toshiharu Nakagawa

Publications and source records attributed to Toshiharu Nakagawa.

3 recordsLinked to original sources

arXiv2008

Rotating Kaluza-Klein Multi-Black Holes with Godel Parameter

We obtain new five-dimensional supersymmetric rotating multi-Kaluza-Klein black hole solutions with the Godel parameter in the Einstein-Maxwell system with a Chern-Simons term. These solutions have no closed timelike curve outside the black hole horizons. At the infinity, the space-time is effectively four-dimensional. Each horizon admits various lens space topologies L(n;1)=S^3/Z_n in addition to a round S^3. The space-time can have outer ergoregions disjointed from the black hole horizons, as well as inner ergoregions attached to each horizon. We discuss the rich structures of ergoregions.

hep-th↗

arXiv2008

Squashed Kerr-Godel Black Holes - Kaluza-Klein Black Holes with Rotations of Black Hole and Universe -

Applying squashing transformation to Kerr-Godel black hole solutions, we present a new type of a rotating Kaluza-Klein black hole solution to the five-dimensional Einstein-Maxwell theory with a Chern-Simon term. The new solutions generated via the squashing transformation have no closed timelike curve everywhere outside the black hole horizons. At the infinity, the metric asymptotically approaches a twisted S^1 bundle over a four-dimensional Minkowski space-time. One of the remarkable features is that the solution has two independent rotation parameters along an extra dimension associated with the black hole's rotation and the Godel's rotation. The space-time also admits the existence of two disconnected ergoregions, an inner ergoregion and an outer ergoregion. These two ergoregions can rotate in the opposite direction as well as in the same direction.

hep-th↗

arXiv2007

Charged Rotating Kaluza-Klein Black Holes in Five Dimensions

We construct a new charged rotating Kaluza-Klein black hole solution in the five-dimensional Einstein-Maxwell theory with a Chern-Simon term. The features of the solutions are also investigated. The spacetime is asymptotically locally flat, i.e., it asymptotes to a twisted $\rm S^1$ bundle over the four-dimensional Minkowski spacetime. The solution describe a non-BPS black hole rotating in the direction of the extra dimension. The solutions have the limits to the supersymmetric black hole solutions, a new extreme non-BPS black hole solutions and a new rotating non-BPS black hole solution with a constant twisted $\rm S^1$ fiber.

hep-th↗