4,657 research outputs found
Scalar Quartic Effective Action on
We review the recent results concerning the computation of cubic and quartic
couplings of scalar fields in type IIB supergravity on AdS_5\times S^5
background that are dual to (extended) chiral primary operators in N=4 SYM_4.
We discuss the vanishing of certain cubic and quartic couplings and
non-renormalization property of corresponding correlators in the conformal
field theoryComment: 6 pages, Latex, JHEP style; based on the talk by G. Arutyunov at the
TMR Meeting "Quantum Aspects of Gauge Theories, Supersymmetry and
Unification" held in Paris, September 199
Stationary strings near a higher-dimensional rotating black hole
We study stationary string configurations in a space-time of a
higher-dimensional rotating black hole. We demonstrate that the Nambu-Goto
equations for a stationary string in the 5D Myers-Perry metric allow a
separation of variables. We present these equations in the first-order form and
study their properties. We prove that the only stationary string configuration
which crosses the infinite red-shift surface and remains regular there is a
principal Killing string. A worldsheet of such a string is generated by a
principal null geodesic and a timelike at infinity Killing vector field. We
obtain principal Killing string solutions in the Myers-Perry metrics with an
arbitrary number of dimensions. It is shown that due to the interaction of a
string with a rotating black hole there is an angular momentum transfer from
the black hole to the string. We calculate the rate of this transfer in a
spacetime with an arbitrary number of dimensions. This effect slows down the
rotation of the black hole. We discuss possible final stationary configurations
of a rotating black hole interacting with a string.Comment: 13 pages, contains additianal material at the end of Section 8, also
small misprints are correcte
Integrable Hamiltonian for Classical Strings on AdS_5 x S^5
We find the Hamiltonian for physical excitations of the classical bosonic
string propagating in the AdS_5 x S^5 space-time. The Hamiltonian is obtained
in a so-called uniform gauge which is related to the static gauge by a 2d
duality transformation. The Hamiltonian is of the Nambu type and depends on two
parameters: a single S^5 angular momentum J and the string tension \lambda. In
the general case both parameters can be finite. The space of string states
consists of short and long strings. In the sector of short strings the large J
expansion with \lambda'=\lambda/J^2 fixed recovers the plane-wave Hamiltonian
and higher-order corrections recently studied in the literature. In the strong
coupling limit \lambda\to \infty, J fixed, the energy of short strings scales
as \sqrt[4]{\lambda} while the energy of long strings scales as \sqrt{\lambda}.
We further show that the gauge-fixed Hamiltonian is integrable by constructing
the corresponding Lax representation. We discuss some general properties of the
monodromy matrix, and verify that the asymptotic behavior of the quasi-momentum
perfectly agrees with the one obtained earlier for some specific cases.Comment: 30 pages, LaTex; v2: a few comments added, misprints corrected,
references adde
A note on gravity-scalar fluctuations in holographic RG flow geometries
We study five-dimensional gravity models with non-vanishing background scalar
fields which are dual to non-conformal boundary field theories. We develop a
procedure to decouple the graviton fluctuations from the scalar ones and apply
it to the simplest case of one scalar field. The quadratic action for the
decoupled scalar fluctuations has a very simple form and can be used to compute
two-point functions. We perform this computation for the two examples of
background RG flow recently considered by DeWolfe and Freedman and find
physically reasonable results.Comment: 13 pages, latex, no figure
Perturbative and instanton corrections to the OPE of CPOs in N=4 SYM_4
We study perturbative and instanton corrections to the Operator Product
Expansion of the lowest weight Chiral Primary Operators of N=4 SYM_4. We
confirm the recently observed non-renormalization of various operators (notably
of the double-trace operator with dimension 4 in the 20 irrep of SU(4)), that
appear to be unprotected by unitarity restrictions. We demonstrate the
splitting of the free-field theory stress tensor and R-symmetry current in
supermultiplets acquiring different anomalous dimensions in perturbation theory
and argue that certain double-trace operators also undergo a perturbative
splitting into operators dual to string and two-particle gravity states
respectively. The instanton contributions affect only those double-trace
operators that acquire finite anomalous dimensions at strong coupling. For the
leading operators of this kind, we show that the ratio of their anomalous
dimensions at strong coupling to the anomalous dimensions due to instantons is
the same number.Comment: Latex, 26p, typos are removed, a strong-coupling anomalous dimension
of one of the double-trace operators is correcte
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