From Abelianization to Tangent Categories

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ikonicoff, Sacha, Lemay, Jean-Simon Pacaud, Van der Linden, Tim
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915553665351680
author Ikonicoff, Sacha
Lemay, Jean-Simon Pacaud
Van der Linden, Tim
author_facet Ikonicoff, Sacha
Lemay, Jean-Simon Pacaud
Van der Linden, Tim
contents A tangent category is a category with an endofunctor, called the tangent bundle functor, which is equipped with various natural transformations that capture essential properties of the classical tangent bundle of smooth manifolds. In this paper, we show that, surprisingly, the category of groups is a tangent category whose tangent bundle functor is induced by abelianization and whose differential bundles correspond to abelian groups. We generalize this construction by introducing the concept of linear assignments, which are endofunctors assigning to every object a commutative monoid in a natural and idempotent manner. We then show that a linear assignment induces a tangent bundle functor, whose differential bundles correspond to a notion of linear algebras. We show that any finitely cocomplete regular unital category is a tangent category whose tangent bundle functor is induced by the canonical abelianization functor, which is a monadic linear assignment. This allows us to provide multiple new examples of tangent categories including monoids, pointed magmas, loops, non-unital rings, Jónsson--Tarski varieties, and pointed Mal'tsev varieties.
format Preprint
id arxiv_https___arxiv_org_abs_2510_12324
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle From Abelianization to Tangent Categories
Ikonicoff, Sacha
Lemay, Jean-Simon Pacaud
Van der Linden, Tim
Category Theory
18F40, 18E13
A tangent category is a category with an endofunctor, called the tangent bundle functor, which is equipped with various natural transformations that capture essential properties of the classical tangent bundle of smooth manifolds. In this paper, we show that, surprisingly, the category of groups is a tangent category whose tangent bundle functor is induced by abelianization and whose differential bundles correspond to abelian groups. We generalize this construction by introducing the concept of linear assignments, which are endofunctors assigning to every object a commutative monoid in a natural and idempotent manner. We then show that a linear assignment induces a tangent bundle functor, whose differential bundles correspond to a notion of linear algebras. We show that any finitely cocomplete regular unital category is a tangent category whose tangent bundle functor is induced by the canonical abelianization functor, which is a monadic linear assignment. This allows us to provide multiple new examples of tangent categories including monoids, pointed magmas, loops, non-unital rings, Jónsson--Tarski varieties, and pointed Mal'tsev varieties.
title From Abelianization to Tangent Categories
topic Category Theory
18F40, 18E13
url https://arxiv.org/abs/2510.12324