Aratyn, H.Ferreira, L. A.Gomes, J. F.Zimerman, A. H.2014-05-202014-05-202000-09-08Journal of Physics A-mathematical and General. Bristol: Iop Publishing Ltd, v. 33, n. 35, p. L331-L337, 2000.0305-4470http://hdl.handle.net/11449/23342It is shown how the complex sine-Gordon equation arises as a symmetry flow of the AKNS hierarchy. The AKNS hierarchy is extended by the 'negative' symmetry flows forming the Borel loop algebra. The complex sine-Gordon and the vector nonlinear Schrodinger equations appear as lowest-negative and second-positive flows within the extended hierarchy. This is fully analogous to the well known connection between the sine-Gordon and mKdV equations within the extended mKdV hierarchy. A general formalism for a Toda-like symmetry occupying the 'negative' sector of the sl(N) constrained KP hierarchy and giving rise to the negative Borel sl(N) loop algebra is indicated.L331-L337engCarta10.1088/0305-4470/33/35/101WOS:000089474600001Acesso aberto92877760781495518215976645016606