English

Simple and projective correspondence functors

Representation Theory 2019-02-27 v1 Combinatorics Category Theory Group Theory

Abstract

A correspondence functor is a functor from the category of finite sets and correspondences to the category of kk-modules, where kk is a commutative ring. We determine exactly which simple correspondence functors are projective. Moreover, we analyze the occurrence of such simple projective functors inside the correspondence functor FF associated with a finite lattice and we deduce a direct sum decomposition of FF.

Keywords

Cite

@article{arxiv.1902.09816,
  title  = {Simple and projective correspondence functors},
  author = {Serge Bouc and Jacques Thévenaz},
  journal= {arXiv preprint arXiv:1902.09816},
  year   = {2019}
}