English

Magmal characterisations of cocartesian categories

Category Theory 2025-08-18 v1

Abstract

We present a survey of characterisations of cocartesian categories in terms of monoidal categories - and, more generally, magmal categories - satisfying additional properties. In particular, we show that the following are equivalent for a unital magmal category (M,)(\mathcal M, \otimes), sharpening several classical characterisations. * (M,)(\mathcal M, \otimes) is cocartesian monoidal. * Every object of M\mathcal M admits the structure of a unital magma with respect to \otimes, such that every morphism is a homomorphism, and a single compatibility condition holds between the magma structures and \otimes. * The tensor product functor  ⁣:M×MM{\otimes} \colon \mathcal M \times \mathcal M \to \mathcal M admits a right adjoint.

Keywords

Cite

@article{arxiv.2508.11615,
  title  = {Magmal characterisations of cocartesian categories},
  author = {Nathanael Arkor},
  journal= {arXiv preprint arXiv:2508.11615},
  year   = {2025}
}

Comments

13 pages

R2 v1 2026-07-01T04:52:15.785Z