“…In the absence of long-range interactions it was studied in [21][22][23]. The case γ ≤ 1, which allows for only subsonic phase boundaries, was considered, in [21,23], and nontrivial shock solutions, which occur when γ > 1, were the focus of [22]. However, some important details about existence, structure, and stability of the traveling wave solutions and the fundamental difference between shock and kink solutions remained unclear.…”