Geometric morphisms between toposes of monoid actions: factorization systems
Theory and applications of categories, Bunge Festschrift, Tome 40 (2024), pp. 80-129
Cet article a éte moissonné depuis la source Theory and Applications of Categories website
Let M, N be monoids, and PSh(M), Psh(N) their respective categories of right actions on sets. In this paper, we systematically investigate correspondences between properties of geometric morphisms PSh(M) --> PSh(N) and properties of the semigroup homomorphisms M --> N or flat-left-N-right-M-sets inducing them. More specifically, we consider properties of geometric morphisms featuring in factorization systems, namely: surjections, inclusions, localic morphisms, hyperconnected morphisms, terminal-connected morphisms, étale morphisms, pure morphisms and complete spreads. We end with an application of topos-theoretic Galois theory to the special case of toposes of the form PSh(M).
Publié le :
Classification :
18B25, 20M30
Keywords: topos, monoid, factorization, terminal-connected, étale, pure, complete spread
Keywords: topos, monoid, factorization, terminal-connected, étale, pure, complete spread
@article{TAC_2024_40_a3,
author = {Jens Hemelaer and Morgan Rogers},
title = {Geometric morphisms between toposes of monoid actions: factorization systems},
journal = {Theory and applications of categories},
pages = {80--129},
year = {2024},
volume = {40},
language = {en},
url = {http://geodesic.mathdoc.fr/item/TAC_2024_40_a3/}
}
Jens Hemelaer; Morgan Rogers. Geometric morphisms between toposes of monoid actions: factorization systems. Theory and applications of categories, Bunge Festschrift, Tome 40 (2024), pp. 80-129. http://geodesic.mathdoc.fr/item/TAC_2024_40_a3/