3d Abelian gauge theories at the boundary

Abstract A four-dimensional Abelian gauge field can be coupled to a 3d CFT with a U(1) symmetry living on a boundary. This coupling gives rise to a continuous family of boundary conformal field theories (BCFT) parametrized by the gauge coupling τ in the upper-half plane and by the choice of the CFT...

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Main Authors: Lorenzo Di Pietro, Davide Gaiotto, Edoardo Lauria, Jingxiang Wu
Format: Article
Language:English
Published: SpringerOpen 2019-05-01
Series:Journal of High Energy Physics
Subjects:
Online Access:http://link.springer.com/article/10.1007/JHEP05(2019)091
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author Lorenzo Di Pietro
Davide Gaiotto
Edoardo Lauria
Jingxiang Wu
author_facet Lorenzo Di Pietro
Davide Gaiotto
Edoardo Lauria
Jingxiang Wu
author_sort Lorenzo Di Pietro
collection DOAJ
description Abstract A four-dimensional Abelian gauge field can be coupled to a 3d CFT with a U(1) symmetry living on a boundary. This coupling gives rise to a continuous family of boundary conformal field theories (BCFT) parametrized by the gauge coupling τ in the upper-half plane and by the choice of the CFT in the decoupling limit τ → ∞. Upon performing an SL(2, ℤ) transformation in the bulk and going to the decoupling limit in the new frame, one finds a different 3d CFT on the boundary, related to the original one by Witten’s SL(2, ℤ) action [1]. In particular the cusps on the real τ axis correspond to the 3d gauging of the original CFT. We study general properties of this BCFT. We show how to express bulk one and two-point functions, and the hemisphere free-energy, in terms of the two-point functions of the boundary electric and magnetic currents. We then consider the case in which the 3d CFT is one Dirac fermion. Thanks to 3d dualities this BCFT is mapped to itself by a bulk S transformation, and it also admits a decoupling limit which gives the O(2) model on the boundary. We compute scaling dimensions of boundary operators and the hemisphere free-energy up to two loops. Using an S-duality improved ansatz, we extrapolate the perturbative results and find good approximations to the observables of the O(2) model. We also consider examples with other theories on the boundary, such as large-N f Dirac fermions — for which the extrapolation to strong coupling can be done exactly order-by-order in 1/N f — and a free complex scalar.
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spelling doaj.art-f0f5e47f2fd548a5823429666ff447862022-12-21T20:02:59ZengSpringerOpenJournal of High Energy Physics1029-84792019-05-012019516010.1007/JHEP05(2019)0913d Abelian gauge theories at the boundaryLorenzo Di Pietro0Davide Gaiotto1Edoardo Lauria2Jingxiang Wu3Perimeter Institute for Theoretical PhysicsPerimeter Institute for Theoretical PhysicsCentre for Particle Theory, Department of Mathematical Sciences, Durham UniversityPerimeter Institute for Theoretical PhysicsAbstract A four-dimensional Abelian gauge field can be coupled to a 3d CFT with a U(1) symmetry living on a boundary. This coupling gives rise to a continuous family of boundary conformal field theories (BCFT) parametrized by the gauge coupling τ in the upper-half plane and by the choice of the CFT in the decoupling limit τ → ∞. Upon performing an SL(2, ℤ) transformation in the bulk and going to the decoupling limit in the new frame, one finds a different 3d CFT on the boundary, related to the original one by Witten’s SL(2, ℤ) action [1]. In particular the cusps on the real τ axis correspond to the 3d gauging of the original CFT. We study general properties of this BCFT. We show how to express bulk one and two-point functions, and the hemisphere free-energy, in terms of the two-point functions of the boundary electric and magnetic currents. We then consider the case in which the 3d CFT is one Dirac fermion. Thanks to 3d dualities this BCFT is mapped to itself by a bulk S transformation, and it also admits a decoupling limit which gives the O(2) model on the boundary. We compute scaling dimensions of boundary operators and the hemisphere free-energy up to two loops. Using an S-duality improved ansatz, we extrapolate the perturbative results and find good approximations to the observables of the O(2) model. We also consider examples with other theories on the boundary, such as large-N f Dirac fermions — for which the extrapolation to strong coupling can be done exactly order-by-order in 1/N f — and a free complex scalar.http://link.springer.com/article/10.1007/JHEP05(2019)091Boundary Quantum Field TheoryChern-Simons TheoriesConformal Field TheoryDuality in Gauge Field Theories
spellingShingle Lorenzo Di Pietro
Davide Gaiotto
Edoardo Lauria
Jingxiang Wu
3d Abelian gauge theories at the boundary
Journal of High Energy Physics
Boundary Quantum Field Theory
Chern-Simons Theories
Conformal Field Theory
Duality in Gauge Field Theories
title 3d Abelian gauge theories at the boundary
title_full 3d Abelian gauge theories at the boundary
title_fullStr 3d Abelian gauge theories at the boundary
title_full_unstemmed 3d Abelian gauge theories at the boundary
title_short 3d Abelian gauge theories at the boundary
title_sort 3d abelian gauge theories at the boundary
topic Boundary Quantum Field Theory
Chern-Simons Theories
Conformal Field Theory
Duality in Gauge Field Theories
url http://link.springer.com/article/10.1007/JHEP05(2019)091
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AT davidegaiotto 3dabeliangaugetheoriesattheboundary
AT edoardolauria 3dabeliangaugetheoriesattheboundary
AT jingxiangwu 3dabeliangaugetheoriesattheboundary