The Bailey transform and Hecke–Rogers identities for the universal mock theta functions

Recently, Garvan obtained two-variable Hecke–Rogers identities for three universal mock theta functions g2(z;q)g2(z;q), g3(z;q)g3(z;q), K(z;q)K(z;q) by using basic hypergeometric functions, and he proposed a problem of finding direct proofs of these identities by using Bailey pair technology. In this paper, we give proofs of Garvan's identities by applying Bailey's transform with the conjugate Bailey pair of Warnaar and three Bailey pairs deduced from two special cases of ψ66 given by Slater. In particular, we obtain a compact form of two-variable Hecke–Rogers identity related to g3(z;q)g3(z;q), which implies the corresponding identity given by Garvan. We also extend these two-variable Hecke–Rogers identities into infinite families.