diff --git a/inputs/lecture_10.tex b/inputs/lecture_10.tex index d032207..3561637 100644 --- a/inputs/lecture_10.tex +++ b/inputs/lecture_10.tex @@ -123,7 +123,7 @@ However, Fourier analysis is not only useful for continuous probability density Let $\bP \in M_1(\lambda)$. Then \[ - \forall x \in \R ~ \bP\left( \{x\} \right) = \lim_{T \to \infty} \frac{1}{2 T} \int_{-T}^T e^{-\i t x } \phi(t) \dif t. + \forall x \in \R .~ \bP\left( \{x\} \right) = \lim_{T \to \infty} \frac{1}{2 T} \int_{-T}^T e^{-\i t x } \phi(t) \dif t. \] \end{theorem} @@ -175,18 +175,18 @@ However, Fourier analysis is not only useful for continuous probability density &=& \int_{\R} \left| \sum_{l} c_l e^{\i t_l x}\right|^2 \ge 0 \end{IEEEeqnarray*} \end{refproof} -\begin{theorem}[Bochner's theorem]\label{bochnersthm} - The converse to \autoref{thm:lec_10thm5} holds, i.e.~ any +\begin{theorem}[Bochner's theorem]\label{thm:bochner} + The converse to \autoref{thm:lec_10thm5} holds, i.e.~any $\phi: \R \to \C$ satisfying (a) and (b) of \autoref{thm:lec_10thm5} must be the Fourier transform of a probability measure $\bP$ on $(\R, \cB(\R))$. \end{theorem} -Unfortunately, we won't prove \autoref{bochnersthm} in this lecture. +Unfortunately, we won't prove \autoref{thm:bochner} in this lecture. \begin{definition}[Convergence in distribution / weak convergence] \label{def:weakconvergence} - We say that $\bP_n \subseteq M_1(\R)$ \vocab[Convergence!weak]{converges weakly} towards $\bP \in M_1(\R)$ (notation: $\bP_n \implies \bP$), iff + We say that $\bP_n \in M_1(\R)$ \vocab[Convergence!weak]{converges weakly} towards $\bP \in M_1(\R)$ (notation: $\bP_n \implies \bP$), iff \[ \forall f \in C_b(\R)~ \int f \dif\bP_n \to \int f \dif\bP. \] @@ -245,6 +245,8 @@ Unfortunately, we won't prove \autoref{bochnersthm} in this lecture. $\bP_n \implies \bP$, where $\bP_n$ is the distribution of $X_n$ and $\bP$ is the distribution of $X$. \end{definition} +It is easy to see, that this is equivalent to $\bE[f(X_n)] \to \bE[f(X)]$ +for all $f \in C_b(\R)$. \begin{example} Let $X_n \coloneqq \frac{1}{n}$ and $F_n$ the distribution function, i.e.~$F_n = \One_{[\frac{1}{n},\infty)}$. diff --git a/inputs/lecture_23.tex b/inputs/lecture_23.tex index df324e6..41b3763 100644 --- a/inputs/lecture_23.tex +++ b/inputs/lecture_23.tex @@ -67,8 +67,8 @@ In this lecture we recall the most important point from the lecture. inversion formula (\autoref{inversionformula}), ... \item Levy's continuity theorem (\autoref{levycontinuity}), (\autoref{genlevycontinuity}) - \item Bockner's theorem for positive definite function % TODO REF - \item Bockner's theorem for the mass at a point (\autoref{bochnersformula}) + \item Bochner's theorem for positive definite function (\autoref{thm:bochner}) + \item Bochner's theorem for the mass at a point (\autoref{bochnersformula}) \item Related notions \todo{TODO} \begin{itemize}