nLab open geometric morphism

Context

Topos Theory

Could not include topos theory - contents

Contents

Idea

The notion of open geometric morphism is the notion of open map for geometric morphisms between toposes.

Definition

$f := (f^* \dashv f_*) : \mathcal{E} \to \mathcal{F}$

is called open if the following equivalent conditions holds

References

• Peter Johnstone, Open maps of toposes, Manuscripta Mathematica, Volume 31, Numbers 1-3 (1980) pp.217-247. (gdz)

• André Joyal, Myles Tierney, An extension of the Galois theory of Grothendieck, Mem. Amer. Math. Soc. 309 (1984).

Revised on November 9, 2014 09:02:38 by Thomas Holder (82.113.98.36)