19 research outputs found
Emerging Non-Anomalous Baryonic Symmetries in the AdS_5/CFT_4 Correspondence
We study the breaking of baryonic symmetries in the AdS_5/CFT_4
correspondence for D3 branes at Calabi-Yau three-fold singularities. This
leads, for particular VEVs, to the emergence of non-anomalous baryonic
symmetries during the renormalization group flow. We claim that these VEVs
correspond to critical values of the B-field moduli in the dual supergravity
backgrounds. We study in detail the C^3/Z_3 orbifold, the cone over F_0 and the
C^3/Z_5 orbifold. For the first two examples, we study the dual supergravity
backgrounds that correspond to the breaking of the emerging baryonic symmetries
and identify the expected Goldstone bosons and global strings in the infra-red.
In doing so we confirm the claim that the emerging symmetries are indeed
non-anomalous baryonic symmetries.Comment: 65 pages, 15 figures;v2: minor changes, published versio
Probing AdS4/CFT3 proposals beyond chiral rings
We calculate the superconformal Witten index for the Chern-Simons-matter
theory which was proposed to describe multiple M2-branes on . We
consider a variant of this model, which exhibits explicit N=3 supersymmetry and
has the advantage of not having an exotic branch of the moduli space. At ,
we compare the index with that from the proposed gravity dual and find a
disagreement.Comment: references added; introduction modifie
5d quivers and their AdS(6) duals
We consider an infinite class of 5d supersymmetric gauge theories involving
products of symplectic and unitary groups that arise from D4-branes at orbifold
singularities in Type I' string theory. The theories are argued to be dual to
warped AdS(6)x S4/Zn backgrounds in massive Type IIA supergravity. In
particular, this demonstrates the existence of supersymmetric 5d fixed points
of quiver type. We analyze the spectrum of gauge fields and charged states in
the supergravity dual, and find a precise agreement with the symmetries and
charged operators in the quiver theories. We also comment on other brane
objects in the supergravity dual and their interpretation in the field
theories.Comment: 29 pages, 15 figure
Charged particle-like branes in ABJM
We study the effect of adding lower dimensional brane charges to the 't Hooft
monopole, di-baryon and baryon vertex configurations in . We show that these configurations capture the background fluxes
in a way that depends on the induced charges, and therefore, require additional
fundamental strings in order to cancel the worldvolume tadpoles. The study of
the dynamics reveals that the charges must lie inside some interval in order to
find well defined configurations, a situation familiar from the baryon vertex
in with charges. For the baryon vertex and the di-baryon the
number of fundamental strings must also lie inside an allowed interval. Our
configurations are sensitive to the flat -field recently suggested in the
literature. We make some comments on its possible role. We also discuss how
these configurations are modified in the presence of a non-zero Romans mass.Comment: 31 pages, 14 figures, discussion of charges improved, published
versio
Baryonic symmetries and M5 branes in the AdS_4/CFT_3 correspondence
We study U(1) symmetries dual to Betti multiplets in the AdS_4/CFT_3
correspondence for M2 branes at Calabi-Yau four-fold singularities. Analysis of
the boundary conditions for vector fields in AdS_4 allows for a choice where
wrapped M5 brane states carrying non-zero charge under such symmetries can be
considered. We begin by focusing on isolated toric singularities without
vanishing six-cycles, and study in detail the cone over Q^{111}. The boundary
conditions considered are dual to a CFT where the gauge group is U(1)^2 x
SU(N)^4. We find agreement between the spectrum of gauge-invariant
baryonic-type operators in this theory and wrapped M5 brane states. Moreover,
the physics of vacua in which these symmetries are spontaneously broken
precisely matches a dual gravity analysis involving resolutions of the
singularity, where we are able to match condensates of the baryonic operators,
Goldstone bosons and global strings. We also argue more generally that theories
where the resolutions have six-cycles are expected to receive non-perturbative
corrections from M5 brane instantons. We give a general formula relating the
instanton action to normalizable harmonic two-forms, and compute it explicitly
for the Q^{222} example. The holographic interpretation of such instantons is
currently unclear.Comment: 92 pages, 10 figure
M5 spikes and operators in the HVZ membrane theory
In this note we study some aspects of the so-called dual ABJM theory
introduced by Hanany, Vegh & Zaffaroni. We analyze the spectrum of chiral
operators, and compare it with the spectrum of functions on the mesonic moduli
space M=C^2\times C^2/Z_k, finding expected agreement for the coherent branch.
A somewhat mysterious extra branch of dimension N^2 opens up at the orbifold
fixed point. We also study BPS solutions which represent M2/M5 intersections.
The mesonic moduli space suggests that there should be two versions of this
spike: one where the M5 lives in the orbifolded C^2 and another where it lives
in the unorbifolded one. While expectedly the first class turns out to be like
the ABJM spike, the latter class looks like a collection of stacks of M5 branes
with fuzzy S^3 profiles. This shows hints of the appearance of the global SO(4)
at the non-abelian level which is otherwise not present in the bosonic
potential. We also study the matching of SUGRA modes with operators in the
coherent branch of the moduli space. As a byproduct, we present some formulae
for the laplacian in conical CY_4 of the form C^n\times CY_{4-n}.Comment: 22 pages, 1 figure. Published version with corrected typos
Towards the F-Theorem: N=2 Field Theories on the Three-Sphere
For 3-dimensional field theories with {\cal N}=2 supersymmetry the Euclidean
path integrals on the three-sphere can be calculated using the method of
localization; they reduce to certain matrix integrals that depend on the
R-charges of the matter fields. We solve a number of such large N matrix models
and calculate the free energy F as a function of the trial R-charges consistent
with the marginality of the superpotential. In all our {\cal N}=2
superconformal examples, the local maximization of F yields answers that scale
as N^{3/2} and agree with the dual M-theory backgrounds AdS_4 x Y, where Y are
7-dimensional Sasaki-Einstein spaces. We also find in toric examples that local
F-maximization is equivalent to the minimization of the volume of Y over the
space of Sasakian metrics, a procedure also referred to as Z-minimization.
Moreover, we find that the functions F and Z are related for any trial
R-charges. In the models we study F is positive and decreases along RG flows.
We therefore propose the "F-theorem" that we hope applies to all 3-d field
theories: the finite part of the free energy on the three-sphere decreases
along RG trajectories and is stationary at RG fixed points. We also show that
in an infinite class of Chern-Simons-matter gauge theories where the
Chern-Simons levels do not sum to zero, the free energy grows as N^{5/3} at
large N. This non-trivial scaling matches that of the free energy of the
gravity duals in type IIA string theory with Romans mass.Comment: 66 pages, 10 figures; v2: refs. added, minor improvement
On nonsupersymmetric \BC^4/\BZ_N, tachyons, terminal singularities and flips
We investigate nonsupersymmetric \BC^4/\BZ_N orbifold singularities using
their description in terms of the string worldsheet conformal field theory and
its close relation with the toric geometry description of these singularities
and their possible resolutions. Analytic and numerical study strongly suggest
the absence of nonsupersymmetric Type II terminal singularities (i.e. with no
marginal or relevant blowup modes) so that there are always moduli or closed
string tachyons that give rise to resolutions of these singularities, although
supersymmetric and Type 0 terminal singularities do exist. Using gauged linear
sigma models, we analyze the phase structure of these singularities, which
often involves 4-dimensional flip transitions, occurring between resolution
endpoints of distinct topology. We then discuss 4-dim analogs of unstable
conifold-like singularities that exhibit flips, in particular their Type II GSO
projection and the phase structure. We also briefly discuss aspects of
M2-branes stacked at such singularities and nonsupersymmetric AdS_4\times
S^7/\BZ_N backgrounds.Comment: Latex, 43pgs incl. appendices, 2 eps figs, v2. minor clarifications
added, to appear in JHE
M2-Branes and Fano 3-folds
A class of supersymmetric gauge theories arising from M2-branes probing
Calabi-Yau 4-folds which are cones over smooth toric Fano 3-folds is
investigated. For each model, the toric data of the mesonic moduli space is
derived using the forward algorithm. The generators of the mesonic moduli space
are determined using Hilbert series. The spectrum of scaling dimensions for
chiral operators is computed.Comment: 128 pages, 39 figures, 42 table
Gravitational and Yang-Mills instantons in holographic RG flows
We study various holographic RG flow solutions involving warped
asymptotically locally Euclidean (ALE) spaces of type. A
two-dimensional RG flow from a UV (2,0) CFT to a (4,0) CFT in the IR is found
in the context of (1,0) six dimensional supergravity, interpolating between
and geometries. We also find
solutions involving non trivial gauge fields in the form of SU(2) Yang-Mills
instantons on ALE spaces. Both flows are of vev type, driven by a vacuum
expectation value of a marginal operator. RG flows in four dimensional field
theories are studied in the type IIB and type I context. In type IIB theory,
the flow interpolates between and geometries. The field theory interpretation is that of an N=2
quiver gauge theory flowing to N=4 SU(n) gauge theory. In type I theory the
solution describes an RG flow from N=2 quiver gauge theory with a product gauge
group to N=2 gauge theory in the IR, with gauge group . The
corresponding geometries are and , respectively. We also
explore more general RG flows, in which both the UV and IR CFTs are N=2 quiver
gauge theories and the corresponding geometries are and . Finally, we discuss the matching between the geometric and
field theoretic pictures of the flows.Comment: 32 pages, 3 figures, typoe corrected and a reference adde