“…When all the external legs and all the internal lines bear the same parameters (say, M = m 1 = · · · = m n = 1 in the diagram above), we are left with the single-scale Bessel moments [23,5,16,21] IKM(a, b; n) := ∞ 0 [I 0 (t)] a [K 0 (t)] b t n d t (1.2) for certain non-negative integers a, b, n ∈ Z ≥0 . In addition to their important rôles in the computation of anomalous magnetic dipole moment [25,24,27] in quantum electrodynamics, these single-scale Bessel moments are also intimately related to motivic integrations in algebraic geometry [7] and modular forms in number theory [31], thus having stimulated intensive mathematical research. For example, various linear relations among Bessel moments, such as π 2 IKM(3, 5; 1) = IKM(1, 7; 1) [conjectured in 16, (148)] and 9π 2 IKM(4, 4; 1) = 14 IKM(2, 6; 1) [conjectured in 16, (147)] had been discovered by numerical experiments, before their formal proofs [35,36] were constructed by algebraic and analytic methods.…”