320 research outputs found
Holographic Stress Tensors for Kerr-AdS Black Holes
We use the counterterm subtraction method to calculate the action and
stress-energy-momentum tensor for the (Kerr) rotating black holes in AdS_{n+1},
for n=2, 3 and 4. We demonstrate that the expressions for the total energy for
the Kerr-AdS_3 and Kerr-AdS_5 spacetimes, in the limit of vanishing black hole
mass, are equal to the Casimir energies of the holographically dual
n-dimensional conformal field theories. In particular, for Kerr-AdS_5, dual to
the case of four dimensional N=4 supersymmetric Yang-Mills theory on the
rotating Einstein universe, we explicitly verify the equality of the zero mass
stress tensor from the two sides of the correspondence, and present the result
for general mass as a prediction from gravity. Amusingly, it is observed in
four dimensions that while the trace of the stress tensor defined using the
standard counterterms does not vanish, its integral does, thereby keeping the
action free of ultraviolet divergences. Using a different regularisation scheme
another stress tensor can be defined, which is traceless.Comment: 9 pages, RevTeX; v5: Note added (as in published PRD version) about
the new stress tensor not having same conserved quantities as old. i.e.,
"improvement" fails. The fascinating reason will be reported on in a separate
publication.
First Law, Counterterms and Kerr-AdS_5 Black Holes
We apply the counterterm subtraction technique to calculate the action and
other quantities for the Kerr--AdS black hole in five dimensions using two
boundary metrics; the Einstein universe and rotating Einstein universe with
arbitrary angular velocity. In both cases, the resulting thermodynamic
quantities satisfy the first law of thermodynamics. We point out that the
reason for the violation of the first law in previous calculations is that the
rotating Einstein universe, used as a boundary metric, was rotating with an
angular velocity that depends on the black hole rotation parameter. Using a new
coordinate system with a boundary metric that has an arbitrary angular
velocity, one can show that the resulting physical quantities satisfy the first
law.Comment: 19 pages, 1 figur
Scale Invariance and the AdS/CFT Correspondence
Using the AdS/CFT correspondence, we show that the Anti-de Sitter (AdS)
rotating (Kerr) black holes in five and seven dimensions provide us with
examples of non-trivial field theories which are scale, but not conformally
invariant. This is demonstrated by our computation of the actions and the
stress-energy tensors of the four and six dimensional field theories residing
on the boundary of these Kerr-AdS black holes spacetimes.Comment: 3 pages. LaTeX, IJMP style. Contribution to proceedings of DPF 2000,
held at Ohio State
Higher Dimensional Taub-NUTs and Taub-Bolts in Einstein-Maxwell Gravity
We present a class of higher dimensional solutions to Einstein-Maxwell
equations in d-dimensions. These solutions are asymptotically locally flat,
de-Sitter, or anti-de Sitter space-times. The solutions we obtained depend on
two extra parameters other than the mass and the nut charge. These two
parameters are the electric charge, q and the electric potential at infinity,
V, which has a non-trivial contribution. We Analyze the conditions one can
impose to obtain Taub-Nut or Taub-Bolt space-times, including the
four-dimensional case. We found that in the nut case these conditions coincide
with that coming from the regularity of the one-form potential at the horizon.
Furthermore, the mass parameter for the higher dimensional solutions depends on
the nut charge and the electric charge or the potential at infinity.Comment: 11 pages, LaTe
A Bestiary of Higher Dimensional Taub-NUT-AdS Spacetimes
We present a menagerie of solutions to the vacuum Einstein equations in six,
eight and ten dimensions. These solutions describe spacetimes which are either
locally asymptotically adS or locally asymptotically flat, and which have
non-trivial topology. We discuss the global structure of these solutions, and
their relevance within the context of M-theory.Comment: 11 pages, LaTex(v4: Comments and references added
Gauge Theories with Time Dependent Couplings and their Cosmological Duals
We consider the N=4 SYM theory in flat 3+1 dimensional spacetime with a time
dependent coupling constant which vanishes at , like . In an
analogous quantum mechanics toy model we find that the response is singular.
The energy diverges at , for a generic state. In addition, if the
phase of the wave function has a wildly oscillating behavior, which does not
allow it to be continued past . A similar effect would make the gauge
theory singular as well, though nontrivial effects of renormalization could
tame this singularity and allow a smooth continuation beyond . The gravity
dual in some cases is known to be a time dependent cosmology which exhibits a
space-like singularity at . Our results, if applicable in the gauge theory
for the case of the vanishing coupling, imply that the singularity is a genuine
sickness and does not admit a meaningful continuation. When the coupling
remains non-zero and becomes small at , the curvature in the bulk becomes
of order the string scale. The gauge theory now admits a time evolution beyond
this point. In this case, a finite amount of energy is produced which possibly
thermalizes and leads to a black hole in the bulk.Comment: 45 pages, 1 figure; v2. minor modifications; v3: PRD version,
conclusions in the field theory case significantly revised to include
possible renormalization effects, quantum mechanics toy model unchanged,
abstract and introduction revised, additional subsection 4.1 adde
Higher Dimensional Kerr-AdS Black Holes and the AdS/CFT Correspondence
Using the counterterm subtraction technique we calculatehe stress-energy
tensor, action, and other physical quantities for Kerr-AdS black holes in
various dimensions. For Kerr-AdS_5 with both rotation parameters non-zero, we
demonstrate that stress-energy tensor, in the zero mass parameter limit, is
equal to the stress tensor of the weakly coupled four dimensional dual field
theory. As a result, the total energy of the generalKerr-AdS_5 black hole at
zero mass parameter, exactly matches the Casimir energy of the dual field
theory. We show that at high temperature, the general Kerr-AdS_5 and
perturbative field theory stress-energy tensors are equal, up to the usual
factor of 3/4. We also use the counterterm technique to calculate the stress
tensors and actions for Kerr-AdS_6, and Kerr-AdS_7 black holes, with one
rotation parameter, and we display the results. We discuss the conformal
anomalies of the field theories dual to the Kerr-AdS_5 and Kerr-AdS_7
spacetimes. In these two field theories, we show that the rotation parameters
break conformal invariance but not scale invariance, a novel result for a
non-trivial field theory. For Kerr-AdS_7 the conformal anomalies calculated on
the gravity side and the dual (0,2) tensor multiplet theory are equal up to 4/7
factor. We expect that the Casimir energy of the free field theory is the same
as the energy of the Kerr-AdS_7 black hole (with zero mass parameter), up to
that factor.Comment: 18 pages, LaTex (v3: references added. footnote added
On Superspace Chern-Simons-like Terms
We search for superspace Chern-Simons-like higher-derivative terms in the low
energy effective actions of supersymmetric theories in four dimensions.
Superspace Chern-Simons-like terms are those gauge-invariant terms which cannot
be written solely in terms of field strength superfields and covariant
derivatives, but in which a gauge potential superfield appears explicitly. We
find one class of such four-derivative terms with N=2 supersymmetry which,
though locally on the Coulomb branch can be written solely in terms of field
strengths, globally cannot be. These terms are classified by certain Dolbeault
cohomology classes on the moduli space. We include a discussion of other
examples of terms in the effective action involving global obstructions on the
Coulomb branch.Comment: 23 pages; a reference and an author email correcte
Higher-Derivative Terms in N=2 Supersymmetric Effective Actions
We show how to systematically construct higher-derivative terms in effective
actions in harmonic superspace despite the infinite redundancy in their
description due to the infinite number of auxiliary fields. Making an
assumption about the absence of certain superspace Chern-Simons-like terms
involving vector multiplets, we write all 3- and 4-derivative terms on Higgs,
Coulomb, and mixed branches. Among these terms are several with only
holomorphic dependence on fields, and at least one satisfies a
non-renormalization theorem. These holomorphic terms include a novel
3-derivative term on mixed branches given as an integral over 3/4 of
superspace. As an illustration of our method, we search for Wess-Zumino terms
in the low energy effective action of N=2 supersymmetric QCD. We show that such
terms occur only on mixed branches. We also present an argument showing that
the combination of space-time locality with supersymmetry implies locality in
the anticommuting superspace coordinates of for unconstrained superfields.Comment: 30 pages. Added references and simplified final form of WZ ter
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