In algebraic geometry, a branch of mathematics, an adequate equivalence relation is an equivalence relation on algebraic cycles of smooth projective varieties used to obtain a well-working theory of such cycles, and in particular, well-defined intersection products.
Pierre Samuel formalized the concept of an adequate equivalence relation in 1958.
They are called "adequate" because dividing out by the equivalence relation is functorial, i.e. push-forward (with change of codimension) and pull-back of cycles is well-defined.
All cycles modulo rational equivalence form the Chow ring.
The most common equivalence relations, listed from strongest to weakest, are gathered in the following table.