Cote n° 127 · pages 2–23
· 27 displayed formulas · Descente non plate : notes manuscrites (s.d.).
Inventory dating : s.d.
Édition de démonstration
\[G \simeq \mathrm{Im}\bigl(F \to i_*(G_U)\bigr) .\]
LaTeX source
\[
G \simeq \mathrm{Im}\bigl(F \to i_*(G_U)\bigr) .
\]\[Y_i \to Y' = \mathrm{Spec}(\widehat{\mathcal{O}}_{Y,y}),\]
LaTeX source
\[
Y_i \to Y' = \mathrm{Spec}(\widehat{\mathcal{O}}_{Y,y}),
\]\[\mathrm{Spec}\bigl(\widehat{\mathcal{O}}_{Y,y} / \mathfrak{m}_y^{i+1}\bigr),
\qquad i \in \mathbb{N} .\]
LaTeX source
\[
\mathrm{Spec}\bigl(\widehat{\mathcal{O}}_{Y,y} / \mathfrak{m}_y^{i+1}\bigr),
\qquad i \in \mathbb{N} .
\]\[\left\lbrace
\begin{array}{l}
\mathcal{O}_{Y,y} \text{ réduit} \\
\mathcal{O}_{X,x} \text{ réduit} \\
f \text{ universellement ouvert (EGA IV 14, 15)} \\
X_y \text{ réduit en les gén.\ maximales } x_i \text{ de } x \text{ dans } X_y \\
(X_y)_{\mathrm{red}} \text{ est géom.\ normal}/k(y)
\end{array}
\right.\]
LaTeX source
\[
\left\lbrace
\begin{array}{l}
\mathcal{O}_{Y,y} \text{ réduit} \\
\mathcal{O}_{X,x} \text{ réduit} \\
f \text{ universellement ouvert (EGA IV 14, 15)} \\
X_y \text{ réduit en les gén.\ maximales } x_i \text{ de } x \text{ dans } X_y \\
(X_y)_{\mathrm{red}} \text{ est géom.\ normal}/k(y)
\end{array}
\right.
\]\[\Downarrow\]
LaTeX source
\[ \Downarrow \]
\[\mathcal{O}_\Lambda^n \xrightarrow{\ u\ } \mathcal{O}_\Lambda\]
LaTeX source
\[
\mathcal{O}_\Lambda^n \xrightarrow{\ u\ } \mathcal{O}_\Lambda
\]\[\Lambda' \mapsto \mathrm{Ker}\bigl(u_{\Lambda'} \colon
\Lambda'^{\,n} \to \Lambda'\bigr)\]
LaTeX source
\[
\Lambda' \mapsto \mathrm{Ker}\bigl(u_{\Lambda'} \colon
\Lambda'^{\,n} \to \Lambda'\bigr)
\]\[H^*(\mathcal{C}_{/\delta}, F) \simeq H^*(\widehat{Z}, F|\widehat{Z})\]
LaTeX source
\[
H^*(\mathcal{C}_{/\delta}, F) \simeq H^*(\widehat{Z}, F|\widehat{Z})
\]\[A = \varprojlim \bigl(A_\alpha = A/\mathfrak{J}^{\alpha+1}\bigr)\]
LaTeX source
\[
A = \varprojlim \bigl(A_\alpha = A/\mathfrak{J}^{\alpha+1}\bigr)
\]\[\left.
\begin{array}{l}
M \to N \\
M_\alpha \xrightarrow{\ \sim\ } N_\alpha
\end{array}
\right\rbrace
\Longrightarrow
\forall\, \mathfrak{p} \in \mathrm{Spec}\, A,\
\mathfrak{J} \not\subset \mathfrak{p},\
M_{\mathfrak{p}} \xrightarrow{\ \sim\ } N_{\mathfrak{p}}\]
LaTeX source
\[
\left.
\begin{array}{l}
M \to N \\
M_\alpha \xrightarrow{\ \sim\ } N_\alpha
\end{array}
\right\rbrace
\Longrightarrow
\forall\, \mathfrak{p} \in \mathrm{Spec}\, A,\
\mathfrak{J} \not\subset \mathfrak{p},\
M_{\mathfrak{p}} \xrightarrow{\ \sim\ } N_{\mathfrak{p}}
\]\[\exists \text{ solution} \Longleftrightarrow \exists \text{ solution
après tt chgt de base } S' \to S,\ S' \text{ artinien ou trait}\]
LaTeX source
\[
\exists \text{ solution} \Longleftrightarrow \exists \text{ solution
après tt chgt de base } S' \to S,\ S' \text{ artinien ou trait}
\]\[H^q(\mathcal{C}_{/\delta_i}, F) \simeq
H^q_{\mathcal{M},\mathcal{C}}(Z_n, F) \quad \ldots\]
LaTeX source
\[
H^q(\mathcal{C}_{/\delta_i}, F) \simeq
H^q_{\mathcal{M},\mathcal{C}}(Z_n, F) \quad \ldots
\]\[0 \to {\varprojlim_n}^{(1)} H^{q-1}_{(\mathcal{M},\mathcal{C})}(X^{(i)}_n, F)
\to H^q(X^{(i)}, F) \to \varprojlim_n H^q_{(\mathcal{M},\mathcal{C})}(X^{(i)}_n, F)
\to 0\]
LaTeX source
\[
0 \to {\varprojlim_n}^{(1)} H^{q-1}_{(\mathcal{M},\mathcal{C})}(X^{(i)}_n, F)
\to H^q(X^{(i)}, F) \to \varprojlim_n H^q_{(\mathcal{M},\mathcal{C})}(X^{(i)}_n, F)
\to 0
\]\[\begin{array}{ccc}
Z_U & \hookrightarrow & Z\,? \\
\cap & & \cap \\
U & \subset & X \\
& \searrow & \downarrow \\
& & Y
\end{array}\]
LaTeX source
\[
\begin{array}{ccc}
Z_U & \hookrightarrow & Z\,? \\
\cap & & \cap \\
U & \subset & X \\
& \searrow & \downarrow \\
& & Y
\end{array}
\]\[\Longleftrightarrow\ \forall y \in Y,\quad Z_y \cap U \supset
\mathrm{Ass}\, Z_y \qquad \text{EGA IV 11.12\,?}\]
LaTeX source
\[
\Longleftrightarrow\ \forall y \in Y,\quad Z_y \cap U \supset
\mathrm{Ass}\, Z_y \qquad \text{EGA IV 11.12\,?}
\]\[\left\lbrace
\begin{array}{l}
Z'_i \cap U'_y \neq \emptyset \\
\text{i.e.\ } Z'_i \cap X'_y \neq \{x'\}
\end{array}
\right.\]
LaTeX source
\[
\left\lbrace
\begin{array}{l}
Z'_i \cap U'_y \neq \emptyset \\
\text{i.e.\ } Z'_i \cap X'_y \neq \{x'\}
\end{array}
\right.
\]\[\begin{array}{llll}
G_{U'} & U' \hookrightarrow X' = X^h & & X'_y \supset U'_y \\
& \qquad\ \downarrow & & \ \downarrow \\
G_U & U \subset X & & X_y \supset U_y
\end{array}\]
LaTeX source
\[
\begin{array}{llll}
G_{U'} & U' \hookrightarrow X' = X^h & & X'_y \supset U'_y \\
& \qquad\ \downarrow & & \ \downarrow \\
G_U & U \subset X & & X_y \supset U_y
\end{array}
\]\[\exists\, J = \{i_1, \ldots, i_n\} \subset I, \qquad
\mathfrak{A}_n = \mathrm{Ker}\Bigl(\underbrace{\widehat{\mathcal{O}}_{Y,y}}_{A}
\to \prod_{\alpha \in J} \mathcal{O}_{Y_\alpha, y_\alpha}\Bigr)
\subset \widehat{\mathfrak{m}}_y^{\,n}\]
LaTeX source
\[
\exists\, J = \{i_1, \ldots, i_n\} \subset I, \qquad
\mathfrak{A}_n = \mathrm{Ker}\Bigl(\underbrace{\widehat{\mathcal{O}}_{Y,y}}_{A}
\to \prod_{\alpha \in J} \mathcal{O}_{Y_\alpha, y_\alpha}\Bigr)
\subset \widehat{\mathfrak{m}}_y^{\,n}
\]\[A \to A/\mathfrak{A}_n \hookrightarrow \prod \mathcal{O}_{Y_\alpha, y_\alpha} .\]
LaTeX source
\[
A \to A/\mathfrak{A}_n \hookrightarrow \prod \mathcal{O}_{Y_\alpha, y_\alpha} .
\]\[\Gamma\bigl(S_\infty, C^{\cdot}(F)_{S_\infty}\bigr) =
\varprojlim \Gamma\bigl(S_i, C^{\cdot}(F)_{S_i}\bigr)\]
LaTeX source
\[
\Gamma\bigl(S_\infty, C^{\cdot}(F)_{S_\infty}\bigr) =
\varprojlim \Gamma\bigl(S_i, C^{\cdot}(F)_{S_i}\bigr)
\]\[H^n(S_\infty, F) \to \varprojlim H^n(S_i, F)\]
LaTeX source
\[ H^n(S_\infty, F) \to \varprojlim H^n(S_i, F) \]
\[H^*(S_\infty, F) \Longleftarrow E_2^{pq} = {\varprojlim_i}^{(p)} H^q(S_i, F)\]
LaTeX source
\[
H^*(S_\infty, F) \Longleftarrow E_2^{pq} = {\varprojlim_i}^{(p)} H^q(S_i, F)
\]\[0 \to {\varprojlim_i}^{(1)} H^{n-1}(S_i, F) \to H^n(S_\infty, F)
\to \varprojlim_i H^n(S_i, F) \to 0\]
LaTeX source
\[
0 \to {\varprojlim_i}^{(1)} H^{n-1}(S_i, F) \to H^n(S_\infty, F)
\to \varprojlim_i H^n(S_i, F) \to 0
\]\[F(Y) \to F(X) \rightrightarrows F(X \times_Y X) .\]
LaTeX source
\[ F(Y) \to F(X) \rightrightarrows F(X \times_Y X) . \]
\[F(Y) \to F(X) \rightrightarrows F(X \times_Y X) .\]
LaTeX source
\[ F(Y) \to F(X) \rightrightarrows F(X \times_Y X) . \]
\[X \xrightarrow{\ u'\ } X'_1 \xrightarrow{\ u''\ } Y ,\]
LaTeX source
\[
X \xrightarrow{\ u'\ } X'_1 \xrightarrow{\ u''\ } Y ,
\]\[0 \to F(S) \to F(S') \rightrightarrows F(S'')\]
LaTeX source
\[ 0 \to F(S) \to F(S') \rightrightarrows F(S'') \]