[1] Univ Seville, Escuela Politecn Super, Dept Fis Aplicada 1, Nonlinear Phys Grp, Seville 41011, Spain
[2] Univ Seville, Inst Matemat, E-41012 Seville, Spain
[3] IISER, Pune 411008, Maharashtra, India
[4] Univ Massachusetts, Dept Math & Stat, Amherst, MA 01003 USA
[5] Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA
[6] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA