Abstract
We classify and enumerate the idempotents in several planar diagram monoids: namely, the Motzkin, Jones (a.k.a. Temperley–Lieb) and Kauffman monoids. The classification is in terms of certain vertex- and edge-coloured graphs associated to Motzkin diagrams. The enumeration is necessarily algorithmic in nature, and is based on parameters associated to cycle components of these graphs. We compare our algorithms to existing algorithms for enumerating idempotents in arbitrary (regular ⁎-) semigroups, and give several tables of calculated values.
Original language | English |
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Pages (from-to) | 351-385 |
Number of pages | 35 |
Journal | Journal of Algebra |
Volume | 522 |
Early online date | 26 Nov 2018 |
DOIs | |
Publication status | Published - 15 Mar 2019 |
Keywords
- Diagram monoids
- Partition monoids
- Motzkin monoids
- Jones monoids
- Temperley–Lieb monoids
- Kauffman monoids
- Idempotents
- Enumeration