Event
M. Barr, McGill
Tuesday, October 10, 2017 14:30to15:30
Burnside Hall
Room 920, 805 rue Sherbrooke Ouest, Montreal, QC, H3A 0B9, CA
Beck modules for a monoid
Given an object X of a category C, a Beck module for X is an abelian group object in the slice category C/X. For a ring R, it is a 2-sided R-module; for a group G, it is a right G-module; for a commutative ring R, it is just an R-module; for a Lie algebra L it is the usual notion of L-module. These depend on the ambient category of course. But when a student in Paris named Leonard Guetta asked me what was a Beck module for a monoid, I assumed it was an ordinary module. But I was wrong. I will describe what it actually is. (This talk has been rescheduled from the previous week.) (Notes for the talk are posted on the seminar webpage.)