“…It is easy to note that D 0 has a large kernel containing all the gradient fields vanishing at the boundary of the support. In response, a vast literature in tensor tomography concerns recovery questions (uniqueness, stability, reconstruction) on the solenoidal part of the tensor field; see the surveys [23,17,8,4,16,22] and reference therein. The problem is originally motivated by engineering practices [29,14,2,24].…”