149 research outputs found
Three-Form Flux with N=2 Supersymmetry on AdS_5 x S^5
In the context of the AdS/CFT correspondence the general form of a three-form
flux perturbation to the AdS_5 x S^5 solution in the type IIB supergravity
which preserves N=2 supersymmetry is obtained. The arbitrary holomorphic
function appearing in the N=1 case studied by Grana and Polchinski is
restricted to a quadratic function of the coordinates transverse to the
D3-branes.Comment: 11 pages, LaTe
Boundary Ground Ring in 2D String Theory
The 2D quantum gravity on a disc, or the non-critical theory of open strings,
is known to exhibit an integrable structure, the boundary ground ring, which
determines completely the boundary correlation functions. Inspired by the
recent progress in boundary Liouville theory, we extend the ground ring
relations to the case of non-vanishing boundary Liouville interaction known
also as FZZT brane in the context of the 2D string theory. The ring relations
yield an over-determined set of functional recurrence equations for the
boundary correlation functions. The ring action closes on an infinite array of
equally spaced FZZT branes for which we propose a matrix model realization. In
this matrix model the boundary ground ring is generated by a pair of complex
matrix fields.Comment: sect. 5 extended, appendix adde
Kundt spacetimes as solutions of topologically massive gravity
We obtain new solutions of topologically massive gravity. We find the general
Kundt solutions, which in three dimensions are spacetimes admitting an
expansion-free null geodesic congruence. The solutions are generically of
algebraic type II, but special cases are types III, N or D. Those of type D are
the known spacelike-squashed AdS_3 solutions, and of type N are the known AdS
pp-waves or new solutions. Those of types II and III are the first known
solutions of these algebraic types. We present explicitly the Kundt solutions
that are CSI spacetimes, for which all scalar polynomial curvature invariants
are constant, whereas for the general case we reduce the field equations to a
series of ordinary differential equations. The CSI solutions of types II and
III are deformations of spacelike-squashed AdS_3 and the round AdS_3,
respectively.Comment: 30 pages. This material has come from splitting v1 of arXiv:0906.3559
into 2 separate papers. v2: minor changes
The Gaugings of Maximal D=6 Supergravity
We construct the most general gaugings of the maximal D=6 supergravity. The
theory is (2,2) supersymmetric, and possesses an on-shell SO(5,5) duality
symmetry which plays a key role in determining its couplings. The field content
includes 16 vector fields that carry a chiral spinor representation of the
duality group. We utilize the embedding tensor method which determines the
appropriate combinations of these vectors that participate in gauging of a
suitable subgroup of SO(5,5). The construction also introduces the magnetic
duals of the 5 two-form potentials and 16 vector fields.Comment: 34 pages, latex, reference added, typo's corrected and minor
improvements mad
CP^{N-1} models and the Quantized 2D Black Holes
We have examined the coupled system of the dilaton gravity and the
theory known as a model of the confinement of massive scalar quarks. After the
quantization of the system, we could see the quantum effect of the gravitation
on the coupling constant of model and how the coupling constant of
dynamically induced gauge field changes near the black hole configuration.Comment: 12 pages, Late
Epsilon-expansion in quantum field theory in curved spacetime
We discuss epsilon-expansion in curved spacetime for asymptotically free and
asymptotically non-free theories. The esistence of stable and unstable fixed
points is investigated for and SU(2) gauge theory. It is shown that
epsilon-expansion maybe compatible with asymptotic freedom on special solutions
of the RG equations in a special case (supersymmetric theory). Using
epsilon-expansion RG technique the effective Lagrangian for covariantly
constant gauge SU(2) field and effective potential for gauged NJL-model are
found in 4-epsilon- dimensional curved space (in linear curvature
approximation). The curvature- induced phase transitions from symmetric phase
to asymmetric phase (chromomagnetic vacuum and chiral symmetry broken phase,
respectively) are discussed for the above two models.Comment: Latex file, 22 pages, July 1997 preprin
Timelike Boundary Liouville Theory
The timelike boundary Liouville (TBL) conformal field theory consisting of a
negative norm boson with an exponential boundary interaction is considered. TBL
and its close cousin, a positive norm boson with a non-hermitian boundary
interaction, arise in the description of the accumulation point of
minimal models, as the worldsheet description of open string tachyon
condensation in string theory and in scaling limits of superconductors with
line defects. Bulk correlators are shown to be exactly soluble. In contrast,
due to OPE singularities near the boundary interaction, the computation of
boundary correlators is a challenging problem which we address but do not fully
solve. Analytic continuation from the known correlators of spatial boundary
Liouville to TBL encounters an infinite accumulation of poles and zeros. A
particular contour prescription is proposed which cancels the poles against the
zeros in the boundary correlator d(\o) of two operators of weight \o^2 and
yields a finite result. A general relation is proposed between two-point CFT
correlators and stringy Bogolubov coefficients, according to which the
magnitude of d(\o) determines the rate of open string pair creation during
tachyon condensation. The rate so obtained agrees at large \o with a
minisuperspace analysis of previous work. It is suggested that the mathematical
ambiguity arising in the prescription for analytic continuation of the
correlators corresponds to the physical ambiguity in the choice of open string
modes and vacua in a time dependent background.Comment: 28 pages, 1 figure, v2 reference and acknowledgement adde
Witten-Nester Energy in Topologically Massive Gravity
We formulate topologically massive supergravity with cosmological constant in
the first order formalism, and construct the Noether supercurrent and
superpotential associated with its local supersymmetry. Using these results, we
construct in ordinary topologically massive gravity the Witten-Nester integral
for conserved charges containing spinors which satisfy a generalized version of
Witten equation on the initial value surface. We show that the Witten-Nester
charge, represented as an integral over the boundary of the initial value
surface produces the Abbott-Deser-Tekin energy for asymptotically anti de
Sitter spacetimes. We consider all values of the Chern-Simons coupling
constant, including the critical value known as the chiral point, and study the
cases of standard Brown-Henneaux boundary conditions, as well as their weaker
version that allow a slower fall-off. Studying the Witten-Nester energy as a
bulk integral over the initial value surface instead, we find a bound on the
energy, and through it the sufficient condition for the positivity of the
energy. In particular, we find that spacetimes of Petrov type N that admit
globally well defined solutions of the generalized Witten equation have
positive energy.Comment: 43 page
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