Automata and coalgebras in categories of species
Abstract
We study generalized automata (in the sense of Ad\'amek-Trnkov\'a) in Joyal's category of (set-valued) combinatorial species, and as an important preliminary step, we study coalgebras for its derivative endofunctor and for the "Euler homogeneity operator" arising from the adjunction . The theory is connected with, and in fact provides relatively nontrivial examples of, "differential 2-rigs", a notion recently introduced by the author putting combinatorial species on the same relation a generic (differential) semiring has with the (differential) semiring of power series with natural coefficients. The desire to study categories of "state machines" valued in an ambient monoidal category gives a pretext to further develop the abstract theory of differential 2-rigs, proving lifting theorems of a differential 2-rig structure from to the category of -algebras on objects of , and to categories of Mealy automata valued in , as well as various constructions inspired by differential algebra such as jet spaces and modules of differential operators. These theorems adapt to various "species-like" categories such as coloured species, -vector species (both used in operad theory), linear species (introduced by Leroux to study combinatorial differential equations), M\"obius species, and others.
Keywords
Cite
@article{arxiv.2401.04242,
title = {Automata and coalgebras in categories of species},
author = {Fosco Loregian},
journal= {arXiv preprint arXiv:2401.04242},
year = {2026}
}
Comments
Hom. Il. 18.371-376; extended version of the note published in the proceedings of CMCS2024