10,691 research outputs found
A one-dimensional theory for Higgs branch operators
We use supersymmetric localization to calculate correlation functions of
half-BPS local operators in 3d superconformal field theories
whose Lagrangian descriptions consist of vectormultiplets coupled to
hypermultiplets. The operators we primarily study are certain twisted linear
combinations of Higgs branch operators that can be inserted anywhere along a
given line. These operators are constructed from the hypermultiplet scalars.
They form a one-dimensional non-commutative operator algebra with topological
correlation functions. The 2- and 3-point functions of Higgs branch operators
in the full 3d theory can be simply inferred from the 1d
topological algebra. After conformally mapping the 3d superconformal field
theory from flat space to a round three-sphere, we preform supersymmetric
localization using a supercharge that does not belong to any 3d
subalgebra of the algebra. The result is a simple model that can
be used to calculate correlation functions in the 1d topological algebra
mentioned above. This model is a 1d Gaussian theory coupled to a matrix model,
and it can be viewed as a gauge-fixed version of a topological gauged quantum
mechanics. Our results generalize to non-conformal theories on that
contain real mass and Fayet-Iliopolous parameters. We also provide partial
results in the 1d topological algebra associated with the Coulomb branch, where
we calculate correlation functions of local operators built from the
vectormultiplet scalars.Comment: 108 pages; v2: typos corrected, some statements clarifie
Bootstrapping Vector Models in
We use the conformal bootstrap to study conformal field theories with
global symmetry in and spacetime dimensions that have a scalar
operator transforming as an vector. The crossing symmetry of
the four-point function of this vector operator, along with unitarity
assumptions, determine constraints on the scaling dimensions of conformal
primary operators in the OPE. Imposing a lower bound on
the second smallest scaling dimension of such an -singlet conformal
primary, and varying the scaling dimension of the lowest one, we obtain an
allowed region that exhibits a kink located very close to the interacting
-symmetric CFT conjectured to exist recently by Fei, Giombi, and
Klebanov. Under reasonable assumptions on the dimension of the second lowest
singlet in the OPE, we observe that this kink
disappears in for small enough , suggesting that in this case an
interacting CFT may cease to exist for below a certain critical
value.Comment: 24 pages, 5 figures; v2 minor improvement
Coulomb Branch Operators and Mirror Symmetry in Three Dimensions
We develop new techniques for computing exact correlation functions of a
class of local operators, including certain monopole operators, in
three-dimensional abelian gauge theories that have
superconformal infrared limits. These operators are position-dependent linear
combinations of Coulomb branch operators. They form a one-dimensional
topological sector that encodes a deformation quantization of the Coulomb
branch chiral ring, and their correlation functions completely fix the ()-point functions of all half-BPS Coulomb branch operators. Using these
results, we provide new derivations of the conformal dimension of half-BPS
monopole operators as well as new and detailed tests of mirror symmetry. Our
main approach involves supersymmetric localization on a hemisphere with
half-BPS boundary conditions, where operator insertions within the hemisphere
are represented by certain shift operators acting on the wavefunction.
By gluing a pair of such wavefunctions, we obtain correlators on with an
arbitrary number of operator insertions. Finally, we show that our results can
be recovered by dimensionally reducing the Schur index of 4D
theories decorated by BPS 't Hooft-Wilson loops.Comment: 92 pages plus appendices, two figures; v2 and v3: typos corrected,
references adde
Transition behavior of k-surface from hyperbola to ellipse
The transition behavior of the k-surface of a lossy anisotropic indefinite slab is investigated. It is found that, if the material loss is taken into account, the k-surface does not show a sudden change from hyperbola to the ellipse when one principle element of the permittivity tensor changes from negative to positive. In fact, after introducing a small material loss, the shape of the k-surface can be a combination of a hyperbola and an ellipse, and a selective high directional transmission can be obtained in such a slab
Regional reserve pooling arrangements
Recently, several emerging market countries in East Asia and Latin America have initiated intra-regional reserve pooling mechanisms. This is puzzling from a traditional risk-diversification perspective, because country-level shocks are more correlated within rather than across regions. This paper provides a novel rationale for intra-regional pooling: if non-contingent reserve assets can be used to support production during a crisis, then a country's reserve accumulation decision affects not only its own production and consumption, but also its trading partners. If consumption through terms of trade effects. These terms of trade adjustments can be fully internalized only by a reserve pool among trading partners. If trade linkages are stronger within rather than across regions, then intra-regional reserve pooling may dominate inter-regional pooling, even if shocks are more correlated within regions.
The Superconformal Bootstrap in Three Dimensions
We analyze the constraints imposed by unitarity and crossing symmetry on the
four-point function of the stress-tensor multiplet of
superconformal field theories in three dimensions. We first derive the
superconformal blocks by analyzing the superconformal Ward identity. Our
results imply that the OPE of the primary operator of the stress-tensor
multiplet with itself must have parity symmetry. We then analyze the relations
between the crossing equations, and we find that these equations are mostly
redundant. We implement the independent crossing constraints numerically and
find bounds on OPE coefficients and operator dimensions as a function of the
stress-tensor central charge. To make contact with known
superconformal field theories, we compute this central charge in a few
particular cases using supersymmetric localization. For limiting values of the
central charge, our numerical bounds are nearly saturated by the large
limit of ABJM theory and also by the free ABJM theory.Comment: 74 pages, 7 figures; v2 refs added, minor improvements; v3 typos
fixe
The Korean system of innovation and the semiconductor industry
노트 : This paper is written as part of the Science Policy Research Unit/Sussex European Institute-joint project ‘‘Innovation Dynamics of Pacific Asia: Implications for Europe’’
Bootstrapping Vector Models with Four Supercharges in
We analyze the conformal bootstrap constraints in theories with four
supercharges and a global flavor symmetry in dimensions. In particular, we consider the 4-point function of
-fundamental chiral operators that have no chiral primary in the
-singlet sector of their OPE. We find features in our numerical bounds
that nearly coincide with the theory of chiral super-fields with
superpotential , as well as general bounds on SCFTs
where vanishes in the chiral ring.Comment: 25 pages, 8 figure
Monopoles and Solitons in Fuzzy Physics
Monopoles and solitons have important topological aspects like quantized
fluxes, winding numbers and curved target spaces. Naive discretizations which
substitute a lattice of points for the underlying manifolds are incapable of
retaining these features in a precise way. We study these problems of discrete
physics and matrix models and discuss mathematically coherent discretizations
of monopoles and solitons using fuzzy physics and noncommutative geometry. A
fuzzy sigma-model action for the two-sphere fulfilling a fuzzy Belavin-Polyakov
bound is also put forth.Comment: 17 pages, Latex. Uses amstex, amssymb.Spelling of the name of one
Author corrected. To appear in Commun.Math.Phy
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