Renormalization and destruction of $1/{\gamma }^2$ tori in the standard nontwist map

A. Apte, A. Wurm, P. J. Morrison

Extending the work of del-Castillo-Negrete, Greene, and Morrison, Physica D {\bf 91}, 1 (1996) and {\bf 100}, 311 (1997) on the standard nontwist map, the breakup of an invariant t…