Rankin-Selberg L-functions on the critical line

Let f and g be two primitive (holomorphic or Maass) cusp forms of arbitrary level, character and infinity parameter by which we mean the weight in the holomorphic case and the spectral parameter in the Maass case. Let L(s,f × g) be the associated Rankin-Selberg L-function.If g is fixed and the infinity parameter _f of f varies, then for s on the critical line, the subconvex estimate is any admissible value for the Ramanujan-Petersson-conjecture.