2-group

This article is about 2-dimensional higher groups. For p-groups with p = 2, see p-group.
Not to be confused with No. 2 Group RAF.

In mathematics, particularly category theory, a 2-group is a groupoid with a way to multiply objects, making it resemble a group. They are part of a larger hierarchy of n-groups. They were introduced by Hoàng Xuân Sính in the late 1960s under the name gr-categories,[1][2] and they are also known as categorical groups.

  1. ^ Hoàng, Xuân Sính (1975), "Gr-catégories", Thesis, archived from the original on 2015-07-21
  2. ^ Baez, John C. (2023). "Hoàng Xuân Sính's thesis: categorifying group theory". arXiv:2308.05119 [math.CT].