separable field extension
A polynomial over a field is separable if all its irreducible factors have distinct roots over the algebraic closure of .
An extension of fields is separable if every element is a root of a separable polynomial over .
Every finite separable field extension is an étale morphism of rings.
If are fields and is separable, then is also separable.
Revised on July 18, 2010 07:05:47
by John Baez