The lattice of noncrossing set partitions is known to admit an R-labeling. Under this labeling, maximal chains give rise to permutations. We discuss structural and enumerative properties of the lattice of noncrossing partitions, which pertain to a new permutation statistic, m(a), defined as the num
On the structure of the lattice of noncrossing partitions
โ Scribed by Rodica Simion; Daniel Ullman
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 882 KB
- Volume
- 98
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
Simion, R. and D. Ullman, On the structure of the lattice of noncrossing partitions, Discrete Mathematics 98 (1991) 193-206.
We show that the lattice of noncrossing (set) partitions is self-dual and that it admits a symmetric chain decomposition.
The self-duality is proved via an order-reversing involution. Two proofs are given of the existence of the symmetric chain decomposition, one recursive and one constructive.
Several identities involving Catalan numbers emerge from the construction of the symmetric chain decomposition.
๐ SIMILAR VOLUMES
A partial ordering is defined for monotone projections on a lattice, such that the set of these mappings is a lattice which is isomorphic to a sublattice of the partition lattice.
A matrix associated with the chromatic join of non-crossing partitions has been introduced by Tutte to generalise the Birkhoff-Lewis equations. A conjecturc is given for its determinant in terms of polynomials having the Beraha numbers among their roots. Corrcsponding results for join and meet on th
Consider the poset 6 n of partitions of an n-element set, ordered by refinement. The sizes of the various ranks within this poset are the Stirling numbers of the second kind. Let a= 1 2 &e log(2)ร4. We prove the following upper bound for the ratio of the size of the largest antichain to the size of
The partition function of the zero-field ``Eight-Vertex'' model on a square M by N lattice is calculated exactly in the limit of M, N large. This model includes the dimer, ice and zerofield Ising, F and KDP models as special cases. In general the free energy has a branch point singularity at a phase
ร 4 1 1 2 2 3 3 4 4 5 5 ลฝ รร 4 as clusters, and of composition of partitions ab s Q. โฃ , โฃ , โฃ , โฃ , 1 2 3 4 ร 4 ร 4 ร 4 4 . ลฝ โฃ , โค , โค , โค , โค , โค by an appropriate juxtaposition cf. p. 868 5 1 2 3 4 5 w x. of 2 . We define the elements of S , รโฃ , โค 4 n ร 4 ร 4 ร 4 ร 4