116 research outputs found
Boundary States of D-branes in AdS_3 Based on Discrete Series
We study D-branes in the Lorentzian AdS_3 background from the viewpoint of
boundary states, emphasizing the role of open-closed duality in string theory.
Employing the world sheet with Lorentzian signature, we construct the Cardy
states with the discrete series. We show that they are compatible with (1)
unitarity and normalizability, and (2) the spectral flow symmetry, in the open
string spectrum. We also discuss their brane interpretation. We further show
that in the case of superstrings on AdS_3 x S^3 x T^4, our Cardy states yield
an infinite number of physical BPS states in the open string channel, on which
the spectral flows act consistently.Comment: 27 pages, latex, no figures, v2: we discuss on the single cover of
AdS_3 rather than the universal cover, reference added, v3: Appendix B and
reference adde
Marginal deformations of 3d supersymmetric U(N) model and broken higher spin symmetry
We examine the marginal deformations of double-trace type in 3d
supersymmetric U(N) model with N complex free bosons and fermions. We compute
the anomalous dimensions of higher spin currents to the 1/N order but to all
orders in the deformation parameters by mainly applying the conformal
perturbation theory. The 3d field theory is supposed to be dual to 4d
supersymmetric Vasiliev theory, and the marginal deformations are argued to
correspond to modifying boundary conditions for bulk scalars and fermions. Thus
the modification should break higher spin gauge symmetry and generate the
masses of higher spin fields. We provide supports for the dual interpretation
by relating bulk computation in terms of Witten diagrams to boundary one in
conformal perturbation theory.Comment: 32 pages, 3 figures, minor changes, references added, published
versio
Three point functions in higher spin AdS_3 holography with 1/N corrections
We examine three point functions with two scalar operators and a higher spin
current in 2d W_N minimal model to the next non-trivial order in 1/N expansion.
The minimal model was proposed to be dual to a 3d higher spin gauge theory, and
1/N corrections should be interpreted as quantum effects in the dual gravity
theory. We develop a simple and systematic method to obtain three point
functions by decomposing four point functions of scalar operators with Virasoro
conformal blocks. Applying the method, we reproduce known results at the
leading order in 1/N and obtain new ones at the next leading order. As
confirmation, we check that our results satisfy relations among three point
functions conjectured before.Comment: 30 pages, no figures, minor changes, a reference added, published
versio
- …