2-groups symmetries of 6d little string theories and T-duality

Authors: Michele Del Zotto, and Kantaro Ohmori

Preprint number: UUITP-34/20

We determine the 2-group structure constants for all the six-dimensional little string theories (LSTs) geometrically engineered in F-theory without frozen singularities. We use this result as a consistency check for T-duality: the 2-groups of a pair of T-dual LSTs have to match. When the T-duality involves a discrete symmetry twist the 2-group used in the matching is modified. We demonstrate the matching of the 2-groups in several examples.