====== Category of partitions of even size ====== The **category of partitions of even size** is a [[category_of_partitions|Banica-Speicher category of partitions]] inducing the corepresentation category of the [[modified symmetric group|modified symmetric groups]]. ===== Definition ===== By the **category of partitions of even size** one denotes the subcategory of the [[category of all partitions]] $\Pscr$ whose morphism class is the //set of all partitions of even size//. It was introduced by Banica and Speicher in [(:ref:BanSp09)]. For all $k,l\in \{0\}\cup \N$, a partition $p\in \Pscr(k,l)$ is said to be **of even size** if $k+l$ is an even number, i.e., if $p$ has evenly many points. It is sometimes said that the category of partitions of even size is the //even part// of the category $\Pscr$ of all partitions. ===== Canonical generator ===== The category of all partitions of even size is the subcategory of $\Pscr$ generated by the set of partitions $\{\crosspart,\fourpart,\singleton \otimes\singleton\}$. ===== Associated easy quantum group ===== Via [[tannaka_krein_duality|Tannaka-Krein duality]] for compact quantum groups, the category of all partitions of even size corresponds to the family $(S'_N)_{N\in \N}$ of [[modified symmetric group|modified symmetric groups]]. ===== References ===== [( :ref:BanSp09 >> author: Banica, Teodor and Speicher, Roland title: Liberation of orthogonal Lie groups year: 2009 journal: Advances in Mathematics volume: 222 issue: 4 pages: 1461--150 url: https://doi.org/10.1016/j.aim.2009.06.009 archivePrefix: arXiv eprint :0808.2628 )]