21 research outputs found

    Topological Manipulations of Quantum Field Theories

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    In this thesis we study some topological aspects of Quantum Field Theories (QFTs). In particular, we study the way in which an arbitrary QFT can be separated into “local” and “global” data by means of a “symmetry Topological Field Theory” (symmetry TFT). We also study how various “topological manipulations” of the global data correspond to various well-known operations that previously existed in the literature, and how the symmetry TFT perspective provides a systematic tool for studying these topological manipulations. We start by reviewing the bijection between G-symmetric d-dimensional QFTs and boundary conditions for G-gauge theories in (d+1)-dimensions, which effectively defines the symmetry TFT. We use this relationship to study the “orbifold groupoids” which control the composition of “topological manipulations,” relating theories with the same local data but different global data. Particular attention is paid to examples in d = 2 dimensions. We also discuss the extension to fermionic symmetry groups and find that the familiar “Jordan-Wigner transformation” (fermionization) and “GSO projection” (bosonization) appear as examples of topological manipulations. We also study applications to fusion categorical symmetries and constraining RG flows in WZW models as well. After this, we present a short chapter showcasing an application of this symmetry TFT framework to the study of minimal models in 2d CFT. In particular, we complete the classification of 2d fermionic unitary minimal models. Finally, we discuss how the symmetry TFT intuition can be used to classify duality defects in QFTs. In particular, we focus on Zm duality defects in holomorphic Vertex Operator Algebras (VOAs) (and especially the E8 lattice VOA), where we use symmetry TFT intuition to conjecture, and then rigorously prove, a formula relating (duality-)defected partition functions to Z2 twists of invariant sub-VOAs

    Duality Defects in E8E_8

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    We classify all non-invertible Kramers-Wannier duality defects in the E8E_8 lattice Vertex Operator Algebra (i.e. the chiral (E8)1(E_8)_1 WZW model) coming from Zm\mathbb{Z}_m symmetries. We illustrate how these defects are systematically obtainable as Z2\mathbb{Z}_2 twists of invariant sub-VOAs, compute defect partition functions for small mm, and verify our results against other techniques. Throughout, we focus on taking a physical perspective and highlight the important moving pieces involved in the calculations. Kac's theorem for finite automorphisms of Lie algebras and contemporary results on holomorphic VOAs play a role. We also provide a perspective from the point of view of (2+1)d Topological Field Theory and provide a rigorous proof that all corresponding Tambara-Yamagami actions on holomorphic VOAs can be obtained in this manner. We include a list of directions for future studies.Comment: 51+15 pages, 7 figures, 8 table

    Semi-Chiral Operators in 4d N=1{\cal N}=1 Gauge Theories

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    We discuss the properties of quarter-BPS local operators in four dimensional N=1{\cal N}=1 supersymmetric Yang-Mills theory using the formalism of holomorphic twists. We study loop corrections both to the space of local operators and to algebraic operations which endow the twisted theory with an infinite symmetry algebra. We classify all single-trace quarter-BPS operators in the planar approximation for SU(N)SU(N) gauge theory and propose a holographic dual description for the twisted theory. We classify perturbative quarter-BPS operators in SU(2)SU(2) and SU(3)SU(3) gauge theories with sufficiently small quantum numbers and discuss possible non-perturbative corrections to the answer. We set up analogous calculations for some theories with matter.Comment: 55+20 pages, 61 footnotes, comments welcom

    A Novel Benzodiazepine Compound Inhibits Yellow Fever Virus Infection by Specifically Targeting NS4B Protein

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    Although a highly effective vaccine is available, the number of yellow fever cases has increased over the past 2 decades, which highlights the pressing need for antiviral therapeutics. In a high-throughput screening campaign, we identified an acetic acid benzodiazepine (BDAA) compound which potently inhibits yellow fever virus (YFV). Interestingly, while treatment of YFV-infected cultures with 2 MBDAA reduced the virion production by greater than 2 logs, the compound was not active against 21 other viruses from 14 different viral families. Selection and genetic analysis of drug-resistant viruses revealed that replacement of the proline at amino acid 219 (P219) of the nonstructural protein 4B (NS4B) with serine, threonine, or alanine conferred YFV with resistance to BDAA without apparent loss of replication fitness in cultured mammalian cells. However, replacement of P219 with glycine conferred BDAA resistance with significant loss of replication ability. Bioinformatics analysis predicts that the P219 amino acid is localized at the endoplasmic reticulum lumen side of the fifth putative transmembrane domain of NS4B, and the mutation may render the viral protein incapable of interacting with BDAA. Our studies thus revealed an important role and the structural basis for the NS4B protein in supporting YFV replication. Moreover, in YFV-infected hamsters, oral administration of BDAA protected 90% of the animals from death, significantly reduced viral load by greater than 2 logs, and attenuated virus infection-induced liver injury and body weight loss. The encouraging preclinical results thus warrant further development of BDAA or its derivatives as antiviral agents to treat yellow fever

    The Science Performance of JWST as Characterized in Commissioning

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    This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Feynman diagrams in four-dimensional holomorphic theories and the Operatope

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    Abstract We study a class of universal Feynman integrals which appear in four-dimensional holomorphic theories. We recast the integrals as the Fourier transform of a certain polytope in the space of loop momenta (a.k.a. the “Operatope”). We derive a set of quadratic recursion relations which appear to fully determine the final answer. Our strategy can be applied to a very general class of twisted supersymmetric quantum field theories
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