Remark 48.11.5. If f : Y \to X is a finite morphism of Noetherian schemes, then the diagram
\xymatrix{ Rf_*a(K) \ar[r]_-{\text{Tr}_{f, K}} \ar@{=}[d] & K \ar@{=}[d] \\ R\mathop{\mathcal{H}\! \mathit{om}}\nolimits _{\mathcal{O}_ X}(f_*\mathcal{O}_ Y, K) \ar[r] & K }
is commutative for K \in D_\mathit{QCoh}^+(\mathcal{O}_ X). This follows from Lemma 48.11.4. The lower horizontal arrow is induced by the map \mathcal{O}_ X \to f_*\mathcal{O}_ Y and the upper horizontal arrow is the trace map discussed in Section 48.7.
Comments (1)
Comment #1586 by Pieter Belmans on
There are also: