Want to take part in these discussions? Sign in if you have an account, or apply for one below
Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.
At least (algebraic) geometers denote inverse image functor/extension of scalars by $f^*$, direct image functor/restriction of scalars by $f_*$ and its right adjoint by $f^!$. Because one wants to think of $f$ being in a geometric direction, that is opposite to the morphism of rings. Geometrically minded algebraists (and sheaf theorists) follow this convention as well.
1 to 3 of 3