diff options
Diffstat (limited to 'vorlesungen/slides/5')
-rw-r--r-- | vorlesungen/slides/5/Makefile.inc | 2 | ||||
-rw-r--r-- | vorlesungen/slides/5/krbeispiele.tex | 99 | ||||
-rw-r--r-- | vorlesungen/slides/5/spektrum.tex | 63 |
3 files changed, 164 insertions, 0 deletions
diff --git a/vorlesungen/slides/5/Makefile.inc b/vorlesungen/slides/5/Makefile.inc index 1707e67..76b9032 100644 --- a/vorlesungen/slides/5/Makefile.inc +++ b/vorlesungen/slides/5/Makefile.inc @@ -22,6 +22,8 @@ chapter5 = \ ../slides/5/reellenormalform.tex \ ../slides/5/cayleyhamilton.tex \ \ + ../slides/5/spektrum.tex \ + \ ../slides/5/konvergenzradius.tex \ ../slides/5/krbeispiele.tex \ ../slides/5/spektralgelfand.tex \ diff --git a/vorlesungen/slides/5/krbeispiele.tex b/vorlesungen/slides/5/krbeispiele.tex new file mode 100644 index 0000000..b51df78 --- /dev/null +++ b/vorlesungen/slides/5/krbeispiele.tex @@ -0,0 +1,99 @@ +% +% krbeispiele.tex +% +% (c) 2021 Prof Dr Andreas Müller, OST Ostschweizer Fachhochschule +% +\begin{frame}[t] +\frametitle{Konvergenzradius --- Beispiele} +\vspace{-20pt} +\begin{columns}[t,onlytextwidth] +\begin{column}{0.48\textwidth} +\begin{block}{Exponentialreihe} +\vspace{-20pt} +\begin{align*} +e^z &= \sum_{k=0}^\infty \frac{z^k}{k!} +\\ +\uncover<2->{ +\frac1k\log k! +} +&\uncover<3->{=\frac1k\sum_{x=1}^k {\color{blue}\log x}} +\uncover<6->{>\frac1k\int_1^k{\color{red}\log x}\,dx} +\\ +& +\ifthenelse{\boolean{presentation}}{ +\only<7>{=\frac1k[x\log x -x]_1^k} +}{} +\only<8->{= +\log k -1 +\frac1k} +\uncover<9->{\to \infty\phantom{\frac1k}} +\\ +\uncover<10->{(k!)^{\frac1k} +&\to\infty}\uncover<11->{ \quad\Rightarrow\quad R = \infty} +\end{align*} +\vspace{-40pt} +\begin{center} +\begin{tikzpicture}[>=latex,thick,scale=0.7] +\uncover<4->{ +\foreach \x in {2,...,9}{ + \fill[color=blue!20] ({\x-1},0) rectangle ({\x},{ln(\x)}); + \draw[color=blue] ({\x-1},0) rectangle ({\x},{ln(\x)}); + \node at ({\x-0.5},{ln(\x)}) [above] {\tiny $\log\x$}; + \draw (\x,-0.1) -- (\x,0.1); + \node at (\x,0) [below] {\tiny$\x$}; +} +\draw (1,-0.1) -- (1,0.1); +\uncover<5->{ +\begin{scope} + \clip (0,-1) rectangle (9.5,2.5); + \fill[color=red!40,opacity=0.5] (0,0) -- (0,-1) + -- plot[domain=0.1:9.1,samples=100] ({\x},{ln(\x)}) + -- (9.1,0) -- cycle; + \draw[color=red] plot[domain=0.1:9.1,samples=100] ({\x},{ln(\x)}); +\end{scope} +} +\draw[->] (-0.2,0) -- (9.4,0) coordinate[label={$x$}]; +\draw[->] (0,-1) -- (0,2.5) coordinate[label={right:$y$}]; +} +\end{tikzpicture} +\end{center} +\end{block} +\end{column} +\begin{column}{0.48\textwidth} +\uncover<12->{% +\begin{block}{Geometrische Reihe} +\vspace{-15pt} +\begin{align*} +\uncover<13->{ +\frac{1}{{\color{blue}1}-z} +&= +\sum_{k=0}^\infty +z^k} +\\ +\uncover<14->{ +a_k&=1} +\uncover<15->{\quad\Rightarrow\quad +|a_k|^{\frac1k}=1} +\\ +\uncover<16->{ +\limsup_{k\to\infty} &= |a_k|^{\frac1k}=1}\uncover<17->{ = \frac1R} +\uncover<18->{\quad\Rightarrow\quad R=1} +\end{align*} +%\uncover<19->{Polstelle bei $z=1$ limitiert Konvergenzradius} +\vspace{-20pt} +\begin{center} +\begin{tikzpicture}[>=latex,thick] +\begin{scope} +\clip (-2.2,-1.5) rectangle (2.2,1.5); +\fill[color=red!20] (0,0) circle[radius=2]; +\draw[color=red] (0,0) circle[radius=2]; +\end{scope} +\draw[->] (-2.2,0) -- (2.5,0) coordinate[label={$\operatorname{Re}z$}]; +\draw[->] (0,-1.6) -- (0,1.8) coordinate[label={right:$\operatorname{Im}z$}]; +\fill[color=blue!20] (2,0) circle[radius=0.08]; +\draw[color=blue] (2,0) circle[radius=0.08]; +\end{tikzpicture} +\end{center} +\end{block}} +\end{column} +\end{columns} +\end{frame} diff --git a/vorlesungen/slides/5/spektrum.tex b/vorlesungen/slides/5/spektrum.tex new file mode 100644 index 0000000..f427c9a --- /dev/null +++ b/vorlesungen/slides/5/spektrum.tex @@ -0,0 +1,63 @@ +% +% spektrum.tex +% +% (c) 2021 Prof Dr Andreas Müller, OST Ostschweizer Fachhochschule +% +\begin{frame}[t] +\setlength{\abovedisplayskip}{5pt} +\setlength{\belowdisplayskip}{5pt} +\frametitle{Spektrum} +\vspace{-15pt} +\begin{columns}[t,onlytextwidth] +\begin{column}{0.48\textwidth} +\begin{block}{Definition} +$A\colon V\to V$ beschränkter Operator zwischen Banach-Räumen +\[ +\operatorname{Sp}A += +\left\{ +\lambda\in\mathbb{C} +\;\left|\; +\begin{minipage}{2cm}\raggedright +$A-\lambda I$ nicht invertierbar +\end{minipage} +\right. +\right\} +\] +\end{block} +\begin{block}{Endlichdimensionale Räume} +\vspace{-15pt} +\begin{align*} +&\lambda\in\operatorname{Sp}A +\\ +\Leftrightarrow\quad&\text{$(A-\lambda I)$ nicht invertierbar} +\\ +\Leftrightarrow\quad&\text{$(A-\lambda I)$ singulär} +\\ +\Leftrightarrow\quad&\ker(A-\lambda I)\ne 0 +\\ +\Leftrightarrow\quad&\exists v\in V, v\ne 0, Av=\lambda v +\end{align*} +$\Rightarrow$ $\operatorname{Sp}A$ ist die Menge der Eigenwerte +\end{block} +\end{column} +\begin{column}{0.48\textwidth} +\begin{block}{Unendlichdimensional} +Es gibt eine Folge $x_n\in V$ von Einheitsvektoren +$\|x_n\|=1$ +mit +\begin{align*} +\lim_{n\to\infty} (A - \lambda)x_n &= 0 +\end{align*} +\end{block} +\begin{block}{Spektrum und Norm} +\[ +\operatorname{Sp}(A) +\subset +\{\lambda\in\mathbb{C}\;|\; +|\lambda|\le \|A\|\} +\] +\end{block} +\end{column} +\end{columns} +\end{frame} |