# Contents

## Definition

An algebraic scheme $X$ is integral if for any Zariski open subset $U\subset X$ the ring of sections $\mathcal{O}_X(U)$ of the structure sheaf over $U$ is an integral domain.

## Properties

### Equivalent characterizations

A scheme is integral iff it is both reduced and irreducible. Integral schemes of finite type over the spectrum of an algebraically closed field correspond (in the sense of equivalence of categories) to classical algebraic varieties.

Revised on May 30, 2013 12:54:48 by Urs Schreiber (82.113.121.121)