% \subsection{Additional Material} % Important stuff not done in the lecture. \subsection{Notions of boundedness} The following is just a short overview of all the notions of boundedness we used in the lecture. \begin{definition}+[Boundedness] Let $\cX$ be a set of random variables. We say that $\cX$ is \begin{itemize} \item \vocab{uniformly bounded} iff \[\sup_{X \in \cX} \sup_{\omega \in \Omega} |X(\omega)| < \infty,\] \item \vocab{dominated by $f \in L^p$} for $p \ge 1$ iff \[ \forall X \in \cX .~ |X| \le f, \] \item \vocab{bounded in $L^p$} for $p \ge 1$ iff \[ \sup_{X \in \cX} \|X\|_{L^p} < \infty, \] \item \vocab{uniformly integrable} iff \[ \forall \epsilon > 0 .~\exists K .~ \forall X \in \cX.~ \bE[|X| \One_{|X| > K}] < \epsilon. \] \end{itemize} \end{definition} \begin{fact}+ Let $\cX$ be a set of random variables. Let $1 < p \le q < \infty$ Then the following implications hold: \begin{figure}[H] \centering \begin{tikzpicture} \node at (0,2.5) (ub) {$\cX$ is uniformly bounded}; \node at (-2.5,1.5) (dq) {$\cX$ is dominated by $f \in L^q$}; \node at (-2.5,0.5) (dp) {$\cX$ is dominated by $f \in L^p$}; \node at (2.5,1.0) (bq) {$\cX$ is bounded in $L^q$}; \node at (2.5,0) (bp) {$\cX$ is bounded in $L^p$}; \node at (-2.5,-0.5) (d1) {$\cX$ is dominated by $f \in L^1$}; \node at (0,-1.5) (ui) {$\cX$ is uniformly integrable}; \node at (2.5,-2.5) (b1) {$\cX$ is bounded in $L^1$}; \draw[double equal sign distance, -implies] (ub) -- (dq); % \draw[double equal sign distance, -implies] (ub) -- (bq); \draw[double equal sign distance, -implies] (bq) -- (bp); \draw[double equal sign distance, -implies] (dq) -- (dp); \draw[double equal sign distance, -implies] (dq) -- (bq); \draw[double equal sign distance, -implies] (dp) -- (bp); \draw[double equal sign distance, -implies] (bp) -- (ui); \draw[double equal sign distance, -implies] (dp) -- (d1); \draw[double equal sign distance, -implies] (d1) -- (ui); \draw[double equal sign distance, -implies] (ui) -- (b1); \end{tikzpicture} \end{figure} \end{fact} \subsection{Laplace Transforms} \todo{Write something about Laplace Transforms}