Maximal 0-1 fillings of moon polyominoes with restricted chain-lengths and rc-graphs
arXiv:1009.3919
Abstract
We show that maximal 0-1-fillings of moon polynomials with restricted chain lengths can be identified with certain rc-graphs, also known as pipe dreams. In particular, this exhibits a connection between maximal 0-1-fillings of Ferrers shapes and Schubert polynomials. Moreover, it entails a bijective proof showing that the number of maximal fillings of a stack polyomino S with no north-east chains longer than k depends only on k and the multiset of column heights of S. Our main contribution is a slightly stronger theorem, which in turn leads us to conjecture that the poset of rc-graphs with covering relation given by generalised chute moves is in fact a lattice.
22 pages, v2: references added, v3: included proof for bijection for stack polyominoes, v4: include conjecture and improve presentation