26,062 research outputs found
Five-Dimensional Charged Rotating Black Holes
We consider charged rotating black holes in 5-dimensional Einstein-Maxwell
theory. These black holes are asymptotically flat, they possess a regular
horizon of spherical topology and two independent angular momenta associated
with two distinct planes of rotation. We discuss their global and horizon
properties, and derive a generalized Smarr formula. We construct these black
holes numerically, focussing on black holes with a single angular momentum, and
with two equal-magnitude angular momenta.Comment: 13 pages, 8 figure
First-order flow equations for extremal black holes in very special geometry
We construct interpolating solutions describing single-center static extremal
non-supersymmetric black holes in four-dimensional N=2 supergravity theories
with cubic prepotentials. To this end, we derive and solve first-order flow
equations for rotating electrically charged extremal black holes in a Taub-NUT
geometry in five dimensions. We then use the connection between five- and
four-dimensional extremal black holes to obtain four-dimensional flow equations
and we give the corresponding solutions.Comment: 21 pages. v2: Summary section adde
Coalescence of Rotating Black Holes on Eguchi-Hanson Space
We obtain new charged rotating multi-black hole solutions on the
Eguchi-Hanson space in the five-dimensional Einstein-Maxwell system with a
Chern-Simons term and a positive cosmological constant. In the two-black holes
case, these solutions describe the coalescence of two rotating black holes with
the spatial topologies of S^3 into a single rotating black hole with the
spatial topology of the lens space S^3/Z_2. We discuss the differences in the
horizon areas between our solutions and the two-centered Klemm-Sabra solutions
which describe the coalescence of two rotating black holes with the spatial
topologies of S^3 into a single rotating black hole with the spatial topology
of S^3.Comment: 20 pages, 9 figure
Shadows of rotating five-dimensional charged EMCS black holes
Higher dimensional theories admit astrophysical objects like supermassive
black holes, which are rather different from standard ones, and their
gravitational lensing features deviate from general relativity. It is well
known that a black hole shadow is a dark region due to the falling geodesics of
photons into the black hole and, if detected, a black hole shadow could be used
to determine which theory of gravity is consistent with observations.
Measurements of the shadow sizes around the black holes can help to evaluate
various parameters of the black hole metric. We study the shapes of the shadow
cast by the rotating five-dimensional charged Einstein-Maxwell-Chern-Simons
(EMCS) black holes, which is characterized by the four parameters, i.e., mass,
two spins, and charge, in which the spin parameters are set equal. We integrate
the null geodesic equations and derive an analytical formula for the shadow of
the five-dimensional EMCS black hole, in turn, to show that size of black hole
shadow is affected due to charge as well as spin. The shadow is a dark zone
covered by a deformed circle, and the size of the shadow decreases with an
increase in the charge when compared with the five-dimensional Myers-Perry
black hole. Interestingly, the distortion increases with charge . The effect
of these parameters on the shape and size of the naked singularity shadow of
five-dimensional EMCS black hole is also discussed.Comment: 27 pages, 9 figures, matches with published versio
Gyromagnetic Ratio of Charged Kerr-Anti-de Sitter Black Holes
We examine the gyromagnetic ratios of rotating and charged AdS black holes in
four and higher spacetime dimensions. We compute the gyromagnetic ratio for
Kerr-AdS black holes with an arbitrary electric charge in four dimensions and
show that it corresponds to g=2 irrespective of the AdS nature of the
spacetime. We also compute the gyromagnetic ratio for Kerr-AdS black holes with
a single angular momentum and with a test electric charge in all higher
dimensions. The gyromagnetic ratio crucially depends on the dimensionless ratio
of the rotation parameter to the curvature radius of the AdS background. At the
critical limit, when the boundary Einstein universe is rotating at the speed of
light, it exhibits a striking feature leading to g=2 regardless of the
spacetime dimension. Next, we extend our consideration to include the exact
metric for five-dimensional rotating charged black holes in minimal gauged
supergravity. We show that the value of the gyromagnetic ratio found in the
"test-charge" approach remains unchanged for these black holes.Comment: New section added; 6 pages, RevTe
An extremization principle for the entropy of rotating BPS black holes in AdS
We show that the Bekenstein-Hawking entropy of a class of BPS electrically
charged rotating black holes in AdS can be obtained by a simple
extremization principle. We expect that this extremization corresponds to the
attractor mechanism for BPS rotating black holes in five-dimensional gauged
supergravity, which is still unknown. The expression to be extremized has a
suggestive resemblance to anomaly polynomials and the supersymmetric Casimir
energy recently studied for super Yang-Mills.Comment: 27 pages; v2: refs added; v3: ref adde
Thermodynamics and Hawking radiation of five-dimensional rotating charged G\"{o}del black holes
We study the thermodynamics of G\"{o}del-type rotating charged black holes in
five-dimensional minimal supergravity. These black holes exhibit some peculiar
features such as the presence of closed time-like curves and the absence of
globally spatial-like Cauchy surface. We explicitly compute their energies,
angular momenta, and electric charges that are consistent with the first law of
thermodynamics. Besides, We extend the covariant anomaly cancellation method,
as well as the approach of the effective action, to derive their Hawking
fluxes. Both the methods of the anomaly cancellation and effective action give
the same Hawking fluxes as those from Planck distribution for blackbody
radiation in the background of the charged rotating G\"{o}del black holes. Our
results further support that Hawking radiation is a quantum phenomenon arising
at the event horizon.Comment: 12 pages, no figures, accepted by PR
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