“…Note that, without the conformal map, the Padé approximation to the Borel transform cannot see any physical singularities beyond the leading ones, because Padé tries to represent the leading branch cut with an array of poles and zeros, which have no physical content beyond a crude representation of the cut, and these unphysical poles therefore obscure further physical singularities. On the other hand, the Padé approximation to the conformally mapped expansion, as described in Appendix C, does not place unphysical singularities on the cut [33,36], so higher physical singularities can be seen. These results suggest a relation between the leading-order renormalon factorial growth and the singularities in the divergent part of the nested diagrams.…”