1,178 research outputs found
The 't Hooft Model As A Hologram
We consider the 3d dual of 1+1 dimensional large-N_c QCD with quarks in the
fundamental representation, also known as the 't Hooft model. 't Hooft solved
this model by deriving a Schroedinger equation for the wavefunction of a parton
inside the meson. In the scale-invariant limit, we show how this equation is
related by a transform to the equation of motion for a scalar field in AdS_3.
We thus find an explicit map between the `parton-x' variable and the radial
coordinate of AdS_3. This direct map allows us to check the AdS/CFT
prescription from the 2d side. We describe various features of the dual in the
conformal limit and to the leading order in conformal symmetry breaking, and
make some comments on the 3d theory in the fully non-conformal regime.Comment: Introduction expanded. References rearranged. The version published
in JHE
Effective Values of Komar Conserved Quantities and Their Applications
We calculate the effective Komar angular momentum for the Kerr-Newman (KN)
black hole. This result is valid at any radial distance on and outside the
black hole event horizon. The effcetive values of mass and angular momentum are
then used to derive an identity () which relates the Komar
conserved charge () corresponding to the null Killing vector
() with the thermodynamic quantities of this black hole. As an
application of this identity the generalised Smarr formula for this black hole
is derived. This establishes the fact that the above identity is a local form
of the inherently non-local generalised Smarr formula.Comment: v3, minor modifications over v2; LaTex, 9 pages, no figures, to
appear in Int. Jour. Theo. Phy
Enigma of ultraluminous X-ray sources may be resolved by 3D-spectroscopy (MPFS data)
The ultraluminous X-ray sources (ULXs) were isolated in external galaxies for
the last 5 years. Their X-ray luminosities exceed 100-10000 times those of
brightest Milky Way black hole binaries and they are extremely variable. There
are two models for the ULXs, the best black hole candidates. 1. They are
supercritical accretion disks around a stellar mass black hole like that in
SS433, observed close to the disk axes. 2. They are Intermediate Mass Black
Holes (of 100-10000 solar masses). Critical observations which may throw light
upon the ULXs nature come from observations of nebulae around the ULXs. We
present results of 3D-spectroscopy of nebulae around several ULXs located in
galaxies at 3-6 Mpc distances. We found that the nebulae to be powered by their
central black holes. The nebulae are shocked and dynamically perturbed probably
by jets. The nebulae are compared with SS433 nebula (W50).Comment: Proceedings of the ESO and Euro3D Workshop "Science Perspectives for
3D Spectroscopy", Garching (Germany), October 10-14, 2005. M. Kissler-Patig,
M.M. Roth and J.R. Walsh (eds.
On the WDVV Equation and M-Theory
A wide class of Seiberg-Witten models constructed by M-theory techniques and
described by non-hyperelliptic Riemann surfaces are shown to possess an
associative algebra of holomorphic differentials. This is a first step towards
proving that also these models satisfy the Witten-Dijkgraaf-Verlinde-Verlinde
equation. In this way, similar results known for simpler Seiberg-Witten models
(described by hyperelliptic Riemann surfaces and constructed without recourse
to M-theory) are extended to certain non-hyperelliptic cases constructed in
M-theory. Our analysis reveals a connection between the algebra of holomorphic
differentials on the Riemann surface and the configuration of M-theory branes
of the corresponding Seiberg-Witten model.Comment: 30 pages, Latex, some corrections made, refs adde
Examples of M5-Brane Elliptic Genera
We determine the modified elliptic genus of an M5-brane wrapped on various
one modulus Calabi-Yau spaces, using modular invariance together with some
known Gopakumar-Vafa invariants of small degrees. As a bonus, we find
nontrivial relations among Gopakumar-Vafa invariants of different degrees and
genera from modular invariance.Comment: 13 page
Non-Local Effects of Multi-Trace Deformations in the AdS/CFT Correspondence
The AdS/CFT correspondence relates deformations of the CFT by "multi-trace
operators" to "non-local string theories". The deformed theories seem to have
non-local interactions in the compact directions of space-time; in the gravity
approximation the deformed theories involve modified boundary conditions on the
fields which are explicitly non-local in the compact directions. In this note
we exhibit a particular non-local property of the resulting space-time theory.
We show that in the usual backgrounds appearing in the AdS/CFT correspondence,
the commutator of two bulk scalar fields at points with a large enough distance
between them in the compact directions and a small enough time-like distance
between them in AdS vanishes, but this is not always true in the deformed
theories. We discuss how this is consistent with causality.Comment: 24 pages, 6 figures, 2 appendices. v2: added reference
Purely Four-dimensional Viable Anomaly Mediation
Anomaly mediation of supersymmetry breaking solves the supersymmetric flavor
problem thanks to its ultraviolet-insensitivity. However, it suffers from two
problems: sleptons have negative masses-squared, and there are likely bulk
moduli that spoil the framework. Here, we present the first fully
ultraviolet-insensitive model of anomaly mediation with positive slepton
masses-squared in a purely four-dimensional framework. Our model is based on
the additional D-term contributions to the sparticle masses, and the conformal
sequestering mechanism.Comment: 7 pages, Uses RevTex4 (included). References modifie
Partition functions and elliptic genera from supergravity
We develop the spacetime aspects of the computation of partition functions
for string/M-theory on AdS(3) xM. Subleading corrections to the semi-classical
result are included systematically, laying the groundwork for comparison with
CFT partition functions via the AdS(3)/CFT(2) correspondence. This leads to a
better understanding of the "Farey tail" expansion of Dijkgraaf et. al. from
the point of view of bulk physics. Besides clarifying various issues, we also
extend the analysis to the N=2 setting with higher derivative effects included.Comment: 34 page
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