higher geometry / derived geometry
Ingredients
Concepts
geometric little (∞,1)-toposes
geometric big (∞,1)-toposes
Constructions
Examples
derived smooth geometry
Theorems
A homomorphism of schemes $f \colon X\to Y$ is
finitely presented at $x\in X$ if there is an affine open neighborhood $U$ containing $x$ and an affine open set $V\subseteq Y$ with $f(U)\subseteq V$ such that $\mathcal{O}_X(U)$ is finitely presented as an $\mathcal{O}_Y(V)$-algebra.
locally finitely presented if it is finitely presented at each $x\in X$.
finitely presented if it is locally finitely presented, quasicompact and quasiseparated.
essentially finitely presented if it is a localization of a finitely presented morphism.
A standard open $Spec(R[\{s\}^{-1}]) \longrightarrow Spec(R)$ (Zariski topology) is of finite presentation. More generally, an étale morphism of schemes is of finite presentation (though essentially by definition so).
The Stacks Project, Section 01TO: Morphisms of finite presentation
wikipedia: Finite, quasi-finite, finite type, and finite presentation morphisms
David Rydh, Why are unramified maps not required to be locally of finite presentation?, MO/206333/2503.
Last revised on December 11, 2020 at 21:49:11. See the history of this page for a list of all contributions to it.