“…For lower-spin values s = 3/2 and s = 2, corresponding to m = n − 1 = 1 and m = n = 2 respectively, the factorisation of the conformal operators (3.12) was observed long ago in [14,29,30]. This factorisation was conjectured, based on lower-spin examples, by Tseytlin [31] for the bosonic m = n and fermionic m = n − 1 cases, and also by Joung and Mkrtchyan [32,33] for certain bosonic CHS models. More recently, the factorisation was proved by several groups [28,34,35] for those bosonic CHS models on AdS d , with even d, which are described by completely symmetric arbitrary spin conformal fields (the m = n case in four dimensions).…”