We investigate the dynamics of the well-known
RSK bijection on permutations when
iterated on various reading words of the recording tableau. In the setting of the
ordinary (row) reading word, we show that there is exactly one fixed point per
partition shape, and that it is always reached within two steps from any starting
permutation.
We also consider the modified dynamical systems formed by iterating RSK on the
column reading word and the
reversed reading word of the recording tableau. We
show that the column reading word gives similar dynamics to the row reading word.
On the other hand, for the reversed reading word, we always reach either a
-cycle
or fixed point after two steps. In fact, we reach a fixed point if and only if the shape
of the initial tableau is self-conjugate.
Keywords
Young tableaux, permutations, dynamical systems, RSK
correspondence