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arXiv · 2604.26418

Quarter-indices for basic ortho-symplectic corners

Yasuyuki Hatsuda·Tadashi Okazaki
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Abstract

We study supersymmetric quarter-indices for corner configurations in 4d $\mathcal{N}=4$ super Yang-Mills theory with orthogonal and symplectic gauge groups. For the basic Y-junctions, we obtain exact closed-form expressions for the indices by making use of the Gustafson type integral formula and the Higgsing method. We demonstrate the equality of the quarter-indices between dual configurations, providing evidence for S-duality of the corner configurations. In the special fugacity limit, the indices admit an interpretation in terms of the vacuum characters of the W-algebras of type BCD, and the Lie superalgebra $\mathfrak{osp}(1|2N)$ as the corner vertex operator algebras.

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Yasuyuki Hatsuda, Tadashi Okazaki. 2026-04-29. Quarter-indices for basic ortho-symplectic corners. https://doi.org/10.1007/jhep08(2026)222

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