729 research outputs found
Superdescendants of the D1D5 CFT and their dual 3-charge geometries
We describe how to obtain the gravity duals of semiclassical states in the
D1-D5 CFT that are superdescendants of a class of RR ground states. On the
gravity side, the configurations we construct are regular and asymptotically
reproduce the 3-charge D1-D5-P black hole compactified on . The
geometries depend trivially on the directions but non-trivially on the
remaining 6D space. In the decoupling limit, they reduce to asymptotically
AdS spaces that are dual to CFT states obtained by
acting with (exponentials of) the operators of the superconformal algebra. As
explicit examples, we generalise the solution first constructed in
arXiv:1306.1745 and discuss another class of states that have a more
complicated dual geometry. By using the free orbifold description of the CFT we
calculate the average values for momentum and the angular momenta of these
configurations. Finally we compare the CFT results with those obtained in the
bulk from the asymptotically region.Comment: 50 pages; v2: corrected typos; v3: corrected typos, eq. (2.9b)
simplifie
Stationary axisymmetric solutions of five dimensional gravity
We consider stationary axisymmetric solutions of general relativity that
asymptote to five dimensional Minkowski space. It is known that this system has
a hidden SL(3,R) symmetry. We identify an SO(2,1) subgroup of this symmetry
group that preserves the asymptotic boundary conditions. We show that the
action of this subgroup on a static solution generates a one-parameter family
of stationary solutions carrying angular momentum. We conjecture that by
repeated applications of this procedure one can generate all stationary
axisymmetric solutions starting from static ones. As an example, we derive the
Myers-Perry black hole starting from the Schwarzschild solution in five
dimensions.Comment: 31 pages, LaTeX; references adde
The Renormalization of Non-Commutative Field Theories in the Limit of Large Non-Commutativity
We show that renormalized non-commutative scalar field theories do not reduce
to their planar sector in the limit of large non-commutativity. This follows
from the fact that the RG equation of the Wilson-Polchinski type which
describes the genus zero sector of non-commutative field theories couples
generic planar amplitudes with non-planar amplitudes at exceptional values of
the external momenta. We prove that the renormalization problem can be
consistently restricted to this set of amplitudes. In the resulting
renormalized theory non-planar divergences are treated as UV divergences
requiring appropriate non-local counterterms. In 4 dimensions the model turns
out to have one more relevant (non-planar) coupling than its commutative
counterpart. This non-planar coupling is ``evanescent'': although in the
massive (but not in the massless) case its contribution to planar amplitudes
vanishes when the floating cut-off equals the renormalization scale, this
coupling is needed to make the Wilsonian effective action UV finite at all
values of the floating cut-off.Comment: 35 pages, 8 figures; typos correcte
Physical States at the Tachyonic Vacuum of Open String Field Theory
We illustrate a method for computing the number of physical states of open
string theory at the stable tachyonic vacuum in level truncation approximation.
The method is based on the analysis of the gauge-fixed open string field theory
quadratic action that includes Fadeev-Popov ghost string fields. Computations
up to level 9 in the scalar sector are consistent with Sen's conjecture about
the absence of physical open string states at the tachyonic vacuum. We also
derive a long exact cohomology sequence that relates relative and absolute
cohomologies of the BRS operator at the non-perturbative vacuum. We use this
exact result in conjunction with our numerical findings to conclude that the
higher ghost number non-perturbative BRS cohomologies are non-empty.Comment: 43 pages, 16 eps figures, LaTe
D1D5 microstate geometries from string amplitudes
We reproduce the asymptotic expansion of the D1D5 microstate geometries by
computing the emission amplitudes of closed string states from disks with mixed
D1D5 boundary conditions. Thus we provide a direct link between the
supergravity and D-brane descriptions of the D1D5 microstates at non-zero
string coupling. Microscopically, the profile functions characterizing the
microstate solutions are encoded in the choice of a condensate for the twisted
open string states connecting D1 and D5 branes.Comment: 21 pages; added reference
Supergravity Solutions from Floating Branes
We solve the equations of motion of five-dimensional ungauged supergravity
coupled to three U(1) gauge fields using a floating-brane Ansatz in which the
electric potentials are directly related to the gravitational warp factors. We
find a new class of non-BPS solutions, that can be obtained linearly starting
from an Euclidean four-dimensional Einstein-Maxwell base. This class - the
largest known so far - reduces to the BPS and almost-BPS solutions in certain
limits. We solve the equations explicitly when the base space is given by the
Israel-Wilson metric, and obtain solutions describing non-BPS D6 and anti-D6
branes kept in equilibrium by flux. We also examine the action of spectral flow
on solutions with an Israel-Wilson base and show that it relates these
solutions to almost-BPS solutions with a Gibbons-Hawking base.Comment: 24 pages, 1 figur
A Microscopic Model for the Black hole - Black string Phase Transition
Computations in general relativity have revealed an interesting phase diagram for the black hole - black string phase transition, with three different black objects present for a range of mass values. We can add charges to this system by `boosting' plus dualities; this makes only kinematic changes in the gravity computation but has the virtue of bringing the system into the near-extremal domain where a microscopic model can be conjectured. When the compactification radius is very large or very small then we get the microscopic models of 4+1 dimensional near-extremal holes and 3+1 dimensional near-extremal holes respectively (the latter is a uniform black string in 4+1 dimensions). We propose a simple model that interpolates between these limits and reproduces most of the features of the phase diagram. These results should help us understand how `fractionation' of branes works in general situations
The Kontsevich Connection on the Moduli Space of FZZT Liouville Branes
We point out that insertions of matrix fields in (connected amputated)
amplitudes of (generalized) Kontsevich models are given by covariant
derivatives with respect to the Kontsevich moduli. This implies that
correlators are sections of symmetric products of the (holomorphic) tangent
bundle on the (complexified) moduli space of FZZT Liouville branes. We discuss
the relation of Kontsevich parametrization of moduli space with that provided
by either the (p,1) or the (1,p) boundary conformal field theories. It turns
out that the Kontsevich connection captures the contribution of contact terms
to open string amplitudes of boundary cosmological constant operators in the
(1,p) minimal string models. The curvature of the connection is of type (1,1)
and has delta-function singularities at the points in moduli space where
Kontsevich kinetic term vanishes. We also outline the extention of our
formalism to the c=1 string at self-dual radius and discuss the problems that
have to be understood to reconciliate first and second quantized approaches in
this case.Comment: 34 pages, 2 eps figures, LaTex; typos corrected (including title);
more typos fixed, including those in Eqs.(72) and (132
Hamiltonian Formulation of Open WZW Strings
Using a Hamiltonian approach, we construct the classical and quantum theory
of open WZW strings on a strip. (These are the strings which end on WZW
branes.) The development involves non-abelian generalized Dirichlet images in
an essential way. At the classical level, we find a new non-commutative
geometry in which the equal-time coordinate brackets are non-zero at the
world-sheet boundary, and the result is an intrinsically non-abelian effect
which vanishes in the abelian limit. Using the classical theory as a guide to
the quantum theory, we also find the operator algebra and the analogue of the
Knizhnik-Zamolodchikov equations for the the conformal field theory of open WZW
strings.Comment: 34 pages. Added an equation in Appendix C; some typos corrected.
Footnote b changed. Version to appear on IJMP
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