Cyclic Sieving and Plethysm Coefficients
arXiv:1408.6484 · doi:10.1090/tran/7244
Abstract
A combinatorial expression for the coefficient of the Schur function in the expansion of the plethysm is given for all dividing for the cases in which or is rectangular. In these cases, the coefficient is shown to count, up to sign, the number of fixed points of an -element set under the power of an order- cyclic action. If , the action is the Schützenberger involution on semistandard Young tableaux (also known as evacuation), and, if is rectangular, the action is a certain power of Schützenberger and Shimozono's jeu-de-taquin promotion. This work extends results of Stembridge and Rhoades linking fixed points of the Schützenberger actions to ribbon tableaux enumeration. The conclusion for the case is equivalent to the domino tableaux rule of Carré and Leclerc for discriminating between the symmetric and antisymmetric parts of the square of a Schur function.
28 pages, to appear in Trans. Amer. Math. Soc