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arXiv · 1606.08429

Infrared Computations of Defect Schur Indices

Clay Cordova·Davide Gaiotto·Shu-Heng Shao
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Abstract

We conjecture a formula for the Schur index of N=2 four-dimensional theories in the presence of boundary conditions and/or line defects, in terms of the low-energy effective Seiberg-Witten description of the system together with massive BPS excitations. We test our proposal in a variety of examples for SU(2) gauge theories, either conformal or asymptotically free. We use the conjecture to compute these defect-enriched Schur indices for theories which lack a Lagrangian description, such as Argyres-Douglas theories. We demonstrate in various examples that line defect indices can be expressed as sums of characters of the associated two-dimensional chiral algebra and that for Argyres-Douglas theories the line defect OPE reduces in the index to the Verlinde algebra.

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Clay Cordova, Davide Gaiotto, Shu-Heng Shao. 2017-05-26. Infrared Computations of Defect Schur Indices. https://doi.org/10.1007/jhep11(2016)106

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