Lemma 4.3. The parallel transport isomorphisms define a flat connection on .
Proof. Lemma 4.1 (1) implies that we have such parallel transport maps between the fibers over any pair of points and in the base. Note that is generated by the class of the loop obtained from by rotating through degrees around the -axis, to which assigns the identity map, see also Section 6.4. Lemma 4.1 (2) and Theorem 2.4 thus imply that the parallel transport maps between the fibers do not depend on the choice of the path . ∎
Original source: arXiv:1907.12194v5