Plane-parallel waves as duals of the flat background III: T-duality with torsionless $B$-field

Ladislav Hlavaty, Ivo Petr, Filip Petrasek

By addition of non-zero, but torsionless $B$-field, we expand the classification of (non-)Abelian T-duals of the flat background in four dimensions with respect to one-, two-, thre…