Avoiding Colored Partitions of Lengths Two and Three
Abstract
Pattern avoidance in the symmetric group $S_n$ has provided a number of useful connections between seemingly unrelated problems from stack-sorting to Schubert varieties. Recent work has generalized these results to $S_n\wr C_c$, the objects of which can be viewed as "colored permutations". Another body of research that has grown from the study of pattern avoidance in permutations is pattern avoidance in $\Pi_n$, the set of set partitions of $[n]$. Pattern avoidance in set partitions is a generalization of the well-studied notion of noncrossing partitions. Motivated by recent results in pattern avoidance in $S_n \wr C_c$ we provide a catalog of initial results for pattern avoidance in colored partitions, $\Pi_n \wr C_c$. We note that colored set partitions are not a completely new concept. \emph{Signed} (2-colored) set partitions appear in the work of Björner and Wachs involving the homology of partition lattices. However, we seek to study these objects in a new enumerative context.
- Publication:
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arXiv e-prints
- Pub Date:
- March 2011
- DOI:
- 10.48550/arXiv.1103.0239
- arXiv:
- arXiv:1103.0239
- Bibcode:
- 2011arXiv1103.0239G
- Keywords:
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- Mathematics - Combinatorics;
- 05A18
- E-Print:
- 24 pages, 3 tables, to appear in the Permutation Patterns 2010 Proceedings, a special issue of Pure Mathematics and Applications