3,771 research outputs found
Wilson loops in supersymmetric Chern-Simons-matter theories and duality
We study the algebra of BPS Wilson loops in 3d gauge theories with N=2
supersymmetry and Chern-Simons terms. We argue that new relations appear on the
quantum level, and that in many cases this makes the algebra
finite-dimensional. We use our results to propose the mapping of Wilson loops
under Seiberg-like dualities and verify that the proposed map agrees with the
exact results for expectation values of circular Wilson loops. In some cases we
also relate the algebra of Wilson loops to the equivariant quantum K-ring of
certain quasi projective varieties. This generalizes the connection between the
Verlinde algebra and the quantum cohomology of the Grassmannian found by
Witten
Generalized Superconformal Index for Three Dimensional Field Theories
We introduce a generalization of the S^2 x S^1 superconformal index where
background gauge fields with magnetic flux are coupled to the global symmetries
of the theory. This allows one to gauge a global symmetry at the level of the
index, which we use to show the matching of the superconformal index for N=2
SQED with N_f flavors and its mirror dual
Generalized Global Symmetries
A -form global symmetry is a global symmetry for which the charged
operators are of space-time dimension ; e.g. Wilson lines, surface defects,
etc., and the charged excitations have spatial dimensions; e.g. strings,
membranes, etc. Many of the properties of ordinary global symmetries (=0)
apply here. They lead to Ward identities and hence to selection rules on
amplitudes. Such global symmetries can be coupled to classical background
fields and they can be gauged by summing over these classical fields. These
generalized global symmetries can be spontaneously broken (either completely or
to a subgroup). They can also have 't Hooft anomalies, which prevent us from
gauging them, but lead to 't Hooft anomaly matching conditions. Such anomalies
can also lead to anomaly inflow on various defects and exotic Symmetry
Protected Topological phases. Our analysis of these symmetries gives a new
unified perspective of many known phenomena and uncovers new results.Comment: 49 pages plus appendices. v2: references adde
Tests of Seiberg-like Dualities in Three Dimensions
We use localization techniques to study several duality proposals for supersymmetric gauge theories in three dimensions reminiscent of Seiberg duality. We compare the partition functions of dual theories deformed by real mass terms and FI parameters. We find that Seiberg-like duality for N = 3 Chern-Simons gauge theories proposed by Giveon and Kutasov holds on the level of partition functions and is closely related to level-rank duality in pure Chern-Simons theory. We also clarify the relationship between the Giveon-Kutasov duality and a duality in theories of fractional M2 branes and propose a generalization of the latter. Our analysis also confirms previously known results concerning decoupled free sectors in N = 4 gauge theories realized by monopole operators
Exact results for supersymmetric abelian vortex loops in 2+1 dimensions
We define a class of supersymmetric defect loop operators in N = 2 gauge theories in 2 + 1 dimensions. We give a prescription for computing the expectation value of such operators in a generic N = 2 theory on the three-sphere using localization. We elucidate the role of defect loop operators in IR dualities of supersymmetric gauge theories, and write down their transformation properties under the SL(2, Z ) action on conformal theories with abelian global symmetries
Force-Free Gravitational Redshift: Proposed Gravitational Aharonov-Bohm experiment
We propose a feasible laboratory interferometry experiment with matter waves
in a gravitational potential caused by a pair of artificial field-generating
masses. It will demonstrate that the presence of these masses (and, for moving
atoms, time dilation) induces a phase shift, even if it does not cause any
classical force. The phase shift is identical to that produced by the
gravitational redshift (or time dilation) of clocks ticking at the atom's
Compton frequency. In analogy to the Aharonov-Bohm effect in electromagnetism,
the quantum mechanical phase is a function of the gravitational potential and
not the classical forces.Comment: Updated to published versio
MC: Subaru and Hubble Space Telescope Weak-Lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9
The second most significant detection of the Planck Sunyaev Zel'dovich
survey, PLCK~G287.0+32.9 () boasts two similarly bright radio relics
and a radio halo. One radio relic is located kpc northwest of the
X-ray peak and the other Mpc to the southeast. This large difference
suggests that a complex merging scenario is required. A key missing puzzle for
the merging scenario reconstruction is the underlying dark matter distribution
in high resolution. We present a joint Subaru Telescope and {\it Hubble Space
Telescope} weak-lensing analysis of the cluster. Our analysis shows that the
mass distribution features four significant substructures. Of the
substructures, a primary cluster of mass
$M_{200\text{c}}=1.59^{+0.25}_{-0.22}\times 10^{15} \ h^{-1}_{70} \
\text{M}_{\odot}M_{200\text{c}}=1.16^{+0.15}_{-0.13}\times 10^{14} \ h^{-1}_{70} \
\text{M}_{\odot}\sim 400\sim 2M_{200\text{c}}=1.68^{+0.22}_{-0.20}\times
10^{14} \ h^{-1}_{70} \ \text{M}_{\odot}M_{200\text{c}}=1.87^{+0.24}_{-0.22}\times 10^{14} \ h^{-1}_{70} \
\text{M}_{\odot}$, is northwest of the X-ray peak and beyond the NW radio
relic.Comment: 19 pages, 14 figures; Accepted to Ap
Phylogenetic detection of conserved gene clusters in microbial genomes
BACKGROUND: Microbial genomes contain an abundance of genes with conserved proximity forming clusters on the chromosome. However, the conservation can be a result of many factors such as vertical inheritance, or functional selection. Thus, identification of conserved gene clusters that are under functional selection provides an effective channel for gene annotation, microarray screening, and pathway reconstruction. The problem of devising a robust method to identify these conserved gene clusters and to evaluate the significance of the conservation in multiple genomes has a number of implications for comparative, evolutionary and functional genomics as well as synthetic biology. RESULTS: In this paper we describe a new method for detecting conserved gene clusters that incorporates the information captured by a genome phylogenetic tree. We show that our method can overcome the common problem of overestimation of significance due to the bias in the genome database and thereby achieve better accuracy when detecting functionally connected gene clusters. Our results can be accessed at database GeneChords . CONCLUSION: The methodology described in this paper gives a scalable framework for discovering conserved gene clusters in microbial genomes. It serves as a platform for many other functional genomic analyses in microorganisms, such as operon prediction, regulatory site prediction, functional annotation of genes, evolutionary origin and development of gene clusters
Analysis of 1,000+ Type-Strain Genomes Substantially Improves Taxonomic Classification of Alphaproteobacteria.
The class Alphaproteobacteria is comprised of a diverse assemblage of Gram-negative bacteria that includes organisms of varying morphologies, physiologies and habitat preferences many of which are of clinical and ecological importance. Alphaproteobacteria classification has proved to be difficult, not least when taxonomic decisions rested heavily on a limited number of phenotypic features and interpretation of poorly resolved 16S rRNA gene trees. Despite progress in recent years regarding the classification of bacteria assigned to the class, there remains a need to further clarify taxonomic relationships. Here, draft genome sequences of a collection of genomes of more than 1000 Alphaproteobacteria and outgroup type strains were used to infer phylogenetic trees from genome-scale data using the principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families and genera, including taxa recognized as problematic long ago but also quite recent taxa, as well as a few species were shown to be in need of revision. According proposals are made for the recognition of new orders, families and genera, as well as the transfer of a variety of species to other genera and of a variety of genera to other families. In addition, emended descriptions are given for many species mainly involving information on DNA G+C content and (approximate) genome size, both of which are confirmed as valuable taxonomic markers. Similarly, analysis of the gene content was shown to provide valuable taxonomic insights in the class. Significant incongruities between 16S rRNA gene and whole genome trees were not found in the class. The incongruities that became obvious when comparing the results of the present study with existing classifications appeared to be caused mainly by insufficiently resolved 16S rRNA gene trees or incomplete taxon sampling. Another probable cause of misclassifications in the past is the partially low overall fit of phenotypic characters to the sequence-based tree. Even though a significant degree of phylogenetic conservation was detected in all characters investigated, the overall fit to the tree varied considerably
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