Two Generalizations of Posets of Shuffles
โ Scribed by Patricia Hersh
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 308 KB
- Volume
- 97
- Category
- Article
- ISSN
- 0097-3165
No coin nor oath required. For personal study only.
โฆ Synopsis
We study posets defined by Stanley as a multiset generalization of Greene's posets of shuffles. Ehrenborg defined a quasi-symmetric function encoding for the flag f-vector, denoted F P , and we determine F P for shuffle posets of multisets, expressing it as a Schur-positive symmetric function. This leads to several combinatorial formulas as well as proofs that shuffle posets of multisets are supersolvable and have symmetric chain decompositions. We also generalize posets of shuffles to posets for shuffling k words, answering a question of Stanley. Finally, we extend our results about shuffle posets of multisets to k-shuffle posets. 2001
๐ SIMILAR VOLUMES
Simmons, H., Generalized deviations of posets, Discrete Mathematics 98 (1991) 123-139. The deviation and co-deviation of a poset (Lemonnier (1972)) has been generalized by Pouzet and Zaguia (1985) and used in Goodearl and Zimmermann-Huisgen (1986) and Lau et al. In this paper these generalizations a
In this paper we show that the number of pairwise nonisomorphic two-dimensional posets with n elements is asymptotically equivalent to =l n!. This estimate is based on a characterization, in terms of structural decomposmon, of two-d~mensmnal posets having a umque rep~\*sentation as the intersection