From Ramanujan to Kurokawa–Rovinskiĭ
摘要
We show that a function studied by Ramanujan and revisited in a recent paper of Bradley-Thrush in the Ramanujan Journal is closely linked to a Kurokawa-Rovinskiĭ multiple sine. Furthermore we prove that a Ramanujan equality (corrected by Bradley-Thrush) and a similar equality proved by Bradley-Thrush can be obtained, as well as other equalities, by combining a not very well known paper of M. M. Hjortnaes and a long forgotten paper of A. A. Markoff.