% % rieszbeispiel.tex -- slide template % % (c) 2021 Prof Dr Andreas Müller, OST Ostschweizer Fachhochschule % \bgroup \begin{frame}[t] \setlength{\abovedisplayskip}{5pt} \setlength{\belowdisplayskip}{5pt} \frametitle{Linearform auf $L^2$-Funktionen} \vspace{-20pt} \begin{columns}[t,onlytextwidth] \begin{column}{0.48\textwidth} \begin{block}{Linearform auf $\mathbb{C}^n$} \begin{align*} {\color{blue}x}&=\begin{pmatrix}x_1\\x_2\\\vdots\\x_n\end{pmatrix}, & f({\color{blue}x}) &= \begin{pmatrix}f_1&f_2&\dots&f_n\end{pmatrix} {\color{blue}x} \\ \uncover<2->{ {\color{red}v}&= \rlap{$ \begin{pmatrix} \overline{f}_1&\overline{f}_2&\dots&\overline{f}_n \end{pmatrix}^t \uncover<3->{\;\Rightarrow\; f({\color{blue}x})=\langle {\color{red}v},{\color{blue}x}\rangle} $}} \end{align*} \end{block} \end{column} \begin{column}{0.48\textwidth} \uncover<4->{% \begin{block}{Linearform auf $L^2([a,b])$} \begin{align*} {\color{red}x}&\in L^2([a,b]) \\ \uncover<5->{ f&\colon L^2([a,b]) \to \mathbb{C} : {\color{red}x} \mapsto f({\color{red}x})} \intertext{\uncover<6->{Riesz-Darstellungssatz: $\exists {\color{blue}v}\in L^2([a,b])$}} \uncover<7->{f({\color{red}x}) &= \int_a^b {\color{blue}\overline{v}(t)}{\color{red}x(t)}\,dt} \end{align*} \end{block}} \end{column} \end{columns} \begin{center} \begin{tikzpicture}[>=latex,thick] \begin{scope}[xshift=-3.5cm] \def\s{0.058} \foreach \n in {0,...,5}{ \uncover<3->{ \draw[color=red,line width=3pt] ({\n+\s},{1/(\n+0.5)}) -- ({\n+\s},0); \node[color=red] at ({\n},{-0.2+1/(\n+0.5)}) [above right] {$v_\n\mathstrut$}; } \draw[color=blue,line width=3pt] ({\n-\s},{0.4+0.55*sin(200*\n)+0.25*\n}) -- ({\n-\s},0); \node[color=blue] at ({\n},{-0.2+0.4+0.55*sin(200*\n)+0.25*\n}) [above left] {$x_\n\mathstrut$}; } \draw[->] (-0.6,0) -- (6,0) coordinate[label={$n$}]; \draw[->] (-0.5,-0.1) -- (-0.5,2.5) coordinate[label={right:$x$}]; \foreach \n in {0,...,5}{ \fill (\n,0) circle[radius=0.08]; \node at (\n,0) [below] {$\n$\strut}; } \node at (5.6,0) [below] {$\cdots$\strut}; \end{scope} \uncover<4->{ \begin{scope}[xshift=3.5cm] \uncover<7->{ \fill[color=red!40,opacity=0.5] plot[domain=0:5,samples=100] (\x,{1/(\x+0.5)}) -- (5,0) -- (0,0) -- cycle; } \fill[color=blue!40,opacity=0.5] plot[domain=0:5,samples=100] (\x,{0.4+0.55*sin(200*\x)+0.25*\x}) -- (5,0) -- (0,0) -- cycle; \uncover<7->{ \draw[color=red,line width=1.4pt] plot[domain=0:5,samples=100] (\x,{1/(\x+0.5)}); \node[color=red] at (0,2) [right] {$x(t)$}; } \draw[color=blue,line width=1.4pt] plot[domain=0:5,samples=100] (\x,{0.4+0.55*sin(200*\x)+0.25*\x}); \node[color=blue] at (4.5,2) [right]{$v(t)$}; \draw[->] (-0.6,0) -- (6.0,0) coordinate[label={$t$}]; \draw[->] (-0.5,-0.1) -- (-0.5,2.5) coordinate[label={right:$x$}]; \draw (0.0,-0.1) -- (0.0,0.1); \node at (0.0,0) [below] {$a$\strut}; \draw (5.0,-0.1) -- (5.0,0.1); \node at (5.0,0) [below] {$b$\strut}; \end{scope} } \end{tikzpicture} \end{center} \end{frame} \egroup