[1] CONACYT, Ctr Invest Matemat AC, CIMAT Unidad Monterrey PITT, Monterrey, Nuevo Leon, Mexico
[2] Univ Sonora, Phys Res Dept, Hermosillo 83000, Sonora, Mexico
[3] Insper, Inst Ensino & Pesquisa, Rua Quata 300, BR-04546240 Sao Paulo, SP, Brazil
[4] Benemerita Univ Autonoma Puebla, Inst Fis, Apartado Postal J-48, Puebla 72570, Mexico