34 research outputs found
SUSY Enhancements in (0,4) Deformations of AdS_3/CFT_2
We discuss a marginal deformation of the SL(2,R) x SU(2) x U(1)^4 WZW model,
which describes string theory on AdS_3 x S^3 x T^4, that corresponds to warping
the S^3 factor. This deformation breaks part of the N=(4,4) supersymmetry of
the undeformed dual CFT to N=(0,4) supersymmetry. In the spirit of work by
Giveon, Kutasov, and Seiberg, we construct the asymptotic spacetime symmetry
algebra from worldsheet operators and find a restoration of (4,4) supersymmetry
at discrete values of the deformation parameter. We explain this result from
various perspectives: the worldsheet, supergravity, and from the singular D1-D5
CFT. The supergravity analysis includes an asymptotic symmetry computation of
the level of the affine SU(2) R-symmetry, which arises purely from B-field
contributions.Comment: 16 pages; v2: references adde
N=1 Sigma Models in AdS_4
We study sigma models in AdS_4 with global N=1 supersymmetry and find that
they differ significantly from their flat-space cousins -- the target space is
constrained to be a Kahler manifold with an exact Kahler form, the
superpotential transforms under Kahler transformations, the space of
supersymmetric vacua is generically a set of isolated points even when the
superpotential vanishes, and the R-symmetry is classically broken by the
cosmological constant. Remarkably, the exactness of the Kahler class is also
required for the sigma model to arise as a decoupling limit of N=1
supergravity, and ensures the vanishing of gravitational anomalies. As simple
applications of these results, we argue that fields with AdS_4 scale masses are
ubiquitous in, for example, type IIB N=1 AdS_4 vacua stabilized near large
volume; we also show that the Affleck-Dine-Seiberg runaway of N_f < N_c SQCD is
regulated by considering the theory in AdS_4.Comment: 32 pages; v2: minor changes and references added; v3: discussion in
sect. 5 extended, version published in JHE
Black Hole Monodromy and Conformal Field Theory
The analytic structure of solutions to the Klein-Gordon equation in a black
hole background, as represented by monodromy data, is intimately related to
black hole thermodynamics. It encodes the "hidden conformal symmetry" of a
non-extremal black hole, and it explains why features of the inner event
horizon appear in scattering data such as greybody factors. This indicates that
hidden conformal symmetry is generic within a universality class of black
holes.Comment: 20 pages, v2 minor corrections, updated reference
Two-Sphere Partition Functions and Gromov-Witten Invariants
Many N=(2,2) two-dimensional nonlinear sigma models with Calabi-Yau target
spaces admit ultraviolet descriptions as N=(2,2) gauge theories (gauged linear
sigma models). We conjecture that the two-sphere partition function of such
ultraviolet gauge theories -- recently computed via localization by Benini et
al. and Doroud et al. -- yields the exact K\"ahler potential on the quantum
K\"ahler moduli space for Calabi-Yau threefold target spaces. In particular,
this allows one to compute the genus zero Gromov-Witten invariants for any such
Calabi-Yau threefold without the use of mirror symmetry. More generally, when
the infrared superconformal fixed point is used to compactify string theory,
this provides a direct method to compute the spacetime K\"ahler potential of
certain moduli (e.g., vector multiplet moduli in type IIA), exactly in
{\alpha}'. We compute these quantities for the quintic and for R{\o}dland's
Pfaffian Calabi-Yau threefold and find agreement with existing results in the
literature. We then apply our methods to a codimension four determinantal
Calabi-Yau threefold in P^7, recently given a nonabelian gauge theory
description by the present authors, for which no mirror Calabi-Yau is currently
known. We derive predictions for its Gromov-Witten invariants and verify that
our predictions satisfy nontrivial geometric checks.Comment: 25 pages + 2 appendices; v2 corrects a divisor in K\"ahler moduli
space and includes a new calculation that confirms a geometric prediction; v3
contains minor update of Gromov-Witten invariant extraction procedur