Starting with a gentle approach to the Alday–Gaiotto–Tachikawa (AGT) correspondence
from its 6d origin, these notes provide a wide (albeit shallow) survey of the literature on …

We determine the structure of 1-form symmetries for all 4d\(\mathcal {N}\)= 2 theories that
have a geometric engineering in terms of type IIB string theory on isolated hypersurface …

A bstract We study the constraints of superconformal symmetry on codimension two defects
in four-dimensional superconformal field theories. We show that the one-point function of the …

The Schur limit of the superconformal index of a four-dimensional N= 2 superconformal field
theory encodes rich physical information about the protected spectrum of the theory. For a …

We prove the conjecture of Gaiotto and Rap\v {c}\'ak that the $ Y $-algebras $ Y_ {L, M,
N}[\psi] $ with one of the parameters $ L, M, N $ zero, are simple one-parameter quotients of …

We study a set of four-dimensional N= 2 superconformal field theories (SCFTs) Γ^(G)
labeled by a pair of simply laced Lie groups Γ and G. They are constructed out of gauging a …

Every 4D N= 2 superconformal field theory T corresponds to an associated vertex operator
algebra V (T), which is in general nonrational with a more involved representation theory …

Flavored modular differential equations sometimes arise from null states or their
descendants in a chiral algebra with continuous flavor symmetry. In this paper we focus on …

A bstract There are two major ways of constructing 4d\(\mathcal {N}\)= 2 superconformal field
theories (SCFTs): the first one is putting a 6d (2, 0) theory on a punctured Riemann surface …

We study a rich set of four-dimensional superconformal field theories with both central
charges identical: a= c. These are constructed via the diagonal N= 2 or N= 1 gauging of the …