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Spell out duality theory a bit more
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Direct the reader to the results computing what f^! is like
in specific cases. One missing case is where one has a smooth
morphism (and not just a smooth and proper morphism). It could
easily be deduced from the properties already esthablished
for the f^! functors in the same way we do for the smooth and
proper case. In fact, one could do this more generally for
locally complete intersection morphisms

TODO: Elucidate relative dualizing complex for lci morphisms
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aisejohan committed Feb 22, 2017
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Expand Up @@ -8555,23 +8555,41 @@ \section{A duality theory}
R\SheafHom_{\mathcal{O}_Y}(Rf_*K, \omega_Y^\bullet)
$$
\end{enumerate}
\item if $f : X \to Y$ is a closed immersion of compactifyable schemes
over $S$, then $f^!(-) = R\SheafHom(\mathcal{O}_X, -)$,
\item if $f : Y \to X$ is a finite morphism of compactifyable schemes
over $S$, then $f_*f^!(-) = R\SheafHom(f_*\mathcal{O}_X, -)$,
\item if $f : X \to Y$ is the inclusion of an effective Cartier divisor
into a compactifyable scheme over $S$, then
$f^!(-) = Lf^*(-) \otimes_{\mathcal{O}_X} \mathcal{O}_Y(-X)[-1]$,
\item if $f : X \to Y$ is a Koszul regular immersion of codimension $c$
into a compactifyable scheme over $S$, then
$f^!(-) \cong Lf^*(-) \otimes_{\mathcal{O}_X} \wedge^c\mathcal{N}[-c]$, and
\item if $f : X \to Y$ is a smooth proper morphism of relative dimension $d$
of compactifyable schemes over $S$, then
$f^!(-) \cong Lf^* \otimes_{\mathcal{O}_X} \Omega^d_{X/Y}[d]$.
\end{enumerate}
See Lemmas
\ref{lemma-pseudo-functor},
\ref{lemma-shriek-dualizing},
\ref{lemma-dualizing-schemes},
\ref{lemma-proper-noetherian-relative},
\ref{lemma-twisted-inverse-image-closed},
\ref{lemma-finite-twisted},
\ref{lemma-sheaf-with-exact-support-effective-Cartier},
\ref{lemma-regular-immersion},
\ref{lemma-smooth-proper},
\ref{lemma-upper-shriek-composition},
\ref{lemma-pseudo-functor},
\ref{lemma-shriek-closed-immersion},
\ref{lemma-shriek-dualizing},
\ref{lemma-shriek-via-duality}, and
\ref{lemma-proper-noetherian-relative}.

\medskip\noindent
\ref{lemma-perfect-comparison-shriek}.
We have obtained our functors by a very abstract procedure
which finally rests on invoking an existence theorem
(Derived Categories, Proposition \ref{derived-proposition-brown}).
This means we have no explicit description of the functors $f^!$.
This can sometimes be a problem. However, as we will see,
often it is enough to know the existence of a dualizing complex
and the duality isomorphism to pin down what it is more exactly.
This means we have, in general, no explicit description of the functors $f^!$.
This can sometimes be a problem. But in fact, it is often enough to know
the existence of a dualizing complex and the duality isomorphism
to pin down $f^!$.



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