“…The Hardy inequality was intensively studied. For example, the Hardy inequalities were considered on the Euclidean space in [19], [20], on the Heisenberg group in [6], [7], on stratified groups in [3], [31,32,33], [36], [42], for the vector fields in [34] and [38], on homogeneous groups in [37], [39]. In [37] (see e.g., [35]), authors showed the Hardy inequality with radial derivative on homogeneous groups in the following form: Theorem 1.4.…”