101 research outputs found
Brane transport in anomalous (2,2) models and localization
We study B-branes in two-dimensional N=(2,2) anomalous models, and their
behaviour as we vary bulk parameters in the quantum K\"ahler moduli space. We
focus on the case of (2,2) theories defined by abelian gauged linear sigma
models (GLSM). We use the hemisphere partition function as a guide to find how
B-branes split in the IR into components supported on Higgs, mixed and Coulomb
branches: this generalizes the band restriction rule of Herbst-Hori-Page to
anomalous models.
As a central example, we work out in detail the case of GLSMs for
Hirzebruch-Jung resolutions of cyclic surface singularities. In these
non-compact models we explain how to compute and regularize the hemisphere
partition function for a brane with compact support, and check that its Higgs
branch component explicitly matches with the geometric central charge of an
object in the derived category.Comment: 67 page
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
Conformal Gravity from AdS/CFT mechanism
We explicitly calculate the induced gravity theory at the boundary of an
asymptotically Anti-de Sitter five dimensional Einstein gravity. We also
display the action that encodes the dynamics of radial diffeomorphisms. It is
found that the induced theory is a four dimensional conformal gravity plus a
scalar field. This calculation confirms some previous results found by a
different approach.Comment: Revtex 8 pages, To be published in Phys. Rev.
Aspects of Defects in 3d-3d Correspondence
In this paper we study supersymmetric co-dimension 2 and 4 defects in the
compactification of the 6d theory of type on a 3-manifold
. The so-called 3d-3d correspondence is a relation between complexified
Chern-Simons theory (with gauge group ) on and a 3d
theory . We establish a dictionary for this
correspondence in the presence of supersymmetric defects, which are knots/links
inside the 3-manifold. Our study employs a number of different methods:
state-integral models for complex Chern-Simons theory, cluster algebra
techniques, domain wall theory , 5d SYM, and also
supergravity analysis through holography. These methods are complementary and
we find agreement between them. In some cases the results lead to highly
non-trivial predictions on the partition function. Our discussion includes a
general expression for the cluster partition function, in particular for
non-maximal punctures and . We also highlight the non-Abelian description
of the 3d theory with defect included, as well as its
Higgsing prescription and the resulting `refinement' in complex CS theory. This
paper is a companion to our shorter paper arXiv:1510.03884, which summarizes
our main results.Comment: 129 pages (sorry), 22 figure
Hybrid models for homological projective duals and noncommutative resolutions
We study hybrid models arising as homological projective duals (HPD) of
certain projective embeddings of Fano manifolds
. More precisely, the category of B-branes of such hybrid models corresponds
to the HPD category of the embedding . B-branes on these hybrid models can
be seen as global matrix factorizations over some compact space or,
equivalently, as the derived category of the sheaf of -modules on
, where is an algebra. This latter interpretation
corresponds to a noncommutative resolution of . We compute explicitly the
algebra by several methods, for some specific class of hybrid
models, and find that in general it takes the form of a smash product of an
algebra with a cyclic group. Then we apply our results to the HPD
of corresponding to a Veronese embedding of projective space and the
projective embedding of Fano complete intersections in .Comment: 50 pages, LaTeX; v3: references added, several improvements on the
examples and the section on complete intersections. Published versio
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