z = (x, ) ∈ R N = R N 1 × R N 2 and ||z|| G = (|x| 2(1+ ) + | | 2 ) 1 2(1+ ) . The results hold true for N < 0 (p, b, ) in (1) and q > q c (p, N , b, ) in (2). Here, 0 and q c are new exponents, which are always larger than the classical critical ones and depend on the parameters p, b and . N = N 1 + (1 + )N 2 is the homogeneous dimension of R N .