String Diagrams and Categorification

Embedding Deligne's category $\mathrm{\underline{Re}p}(S_t)$ in the Heisenberg category (with an appendix by Samuel Nyobe Likeng, Alistair Savage and Christopher Ryba)

“…In this section we recall the definition and some important facts about one of our main objects of study. We refer the reader to [19,29] for a brief treatment of the language of string diagrams and strict linear monoidal categories suited to the current work. For a morphism X in a category, we will denote the identity morphism on X by 1 X .…”