Peter LeFanu Lumsdaine: Classifying subobject operations (jww Martin Brandenburg)
Tid: On 2025-02-05 kl 10.00 - 12.00
Plats: Albano house 1, floor 3, Room U (Kovalevsky)
Medverkande: Peter LeFanu Lumsdaine (Stockholm University)
Abstract
In various categories, one can ask: what are the “natural” operations on subobjects? — where “natural” is w.r.t. the *covariant* subobject functor. In Set, for example, “union” is a natural binary operation — but not the only one! I will discuss this and related questions in various naturally-occurring categories, giving complete classifications in some cases, and partial results in others.