The octahedron recurrence and RSK-correspondence
arXiv:math/0703414
Abstract
We start with an ``algebraic'' RSK-correspondence due to Noumi and Yamada. Given a matrix , we consider a pyramidal array of solid minors of . It turns out that this array satisfies an algebraic variant of octahedron recurrence. The main observation is that this array can also be constructed with the help of some square `genetic' array. Next we tropicalize this algebraic construction and consider -{\em polarized} pyramidal arrays (that is arrays satisfying octahedral relations). As a result we get several bijections, viz: a) a linear bijection between non-negative arrays and supermodular functions; b) a piecewise linear bijection between supermodular functions and the so called infra-modular functions; c) a linear bijection between infra-modular functions and plane partitions. A composition of these bijections yields a bijection between non-negative arrays and plane partitions coinciding with the modified RSK-correspondence.
16 pages, 6 figures