“…In the case of rotational (or spherical) symmetry, one may sometimes solve these and related problems using local results and data avoiding the obstacle when the manifold satisfies the Herglotz condition [12,36,64]. Broken lens rigidity was studied recently in [13], and a broken non-Abelian ray transform in Minkowski space in [63]. Other geometric results include boundary determination from a broken ray transform [32] and a reflection approach using strong symmetry assumptions [34], for example letting to solve the broken ray transforms on flat boxes over closed billiard trajectories [29,33].…”