On Caffarelli-Kohn-Nirenberg inequalities for block-radial functions
  The paper provides weighted Sobolev inequalities of the Caffarelli-Kohn-Nirenberg type for functions with multi-radial symmetry. Similarly to the previously studied radial case, the range of parameters in CKN inequalities can be extended, sometimes to infinity, providing a pointwise estimate similar to the classical radial estimate. Furthermore, the "multi-radial" weights are a stronger singularity than radial weights of the same homogeneity. 
Cyril Tintarev and Leszek Skrzypczak
math.AP math.FA