Comment on "A counterpart of the WKI soliton hierarchy associated with so(3,R)"

TL;DR

This paper clarifies that a recently proposed integrable hierarchy is essentially equivalent to the well-known WKI hierarchy, highlighting the importance of variable transformations in identifying true novelty.

Contribution

It demonstrates that certain recently claimed new integrable hierarchies are actually equivalent to existing ones through simple variable changes.

Findings

The proposed hierarchy is equivalent to the WKI hierarchy.

Many 'new' hierarchies are reparametrizations of known systems.

Emphasizes the need for careful analysis to establish novelty.

Abstract

In the recent paper (Wen-Xiu Ma, Solomon Manukure and Hong-Chan Zheng, arXiv:1405.1089), the authors proposed an integrable hierarchy different from the well-known Wadati-Konno-Ichikawa (WKI) hierarchy. However, using a simple linear change of dependent variables, one can check that their hierarchy is equivalent to the WKI hierarchy. For the same reason, some "new integrable" hierarchies proposed by Wen-Xiu Ma and coworkers in recent e-prints are equivalent to the already known ones.