4 articles
Algebraic stack
An algebraic stack, also called an Artin stack, is a stack in groupoids over schemes that locally looks like a scheme, used for moduli problems.
Deligne–Mumford stack
A Deligne–Mumford stack is an algebraic stack locally modeled on schemes by an étale surjective covering, introduced by Deligne and Mumford in 1969 for the moduli of algebraic curves.
Period mapping
A period mapping assigns to each point in the base of a family of algebraic varieties the cohomology of the fiber, viewed as a point in a moduli space of Hodge structures.
Quotient stack
A quotient stack, also called a quotient algebraic stack, is an algebraic stack of the form [X/G], recording orbits and stabilizers of a group action.