\[
\newcommand{\C}{\mathbb{C}}
\newcommand{\cont}{\operatorname{\mathsf{C}}}
\newcommand{\haar}{\mathsf{m}}
\newcommand{\B}{\mathscr{B}}
\newcommand{\D}{\mathscr{D}}
\newcommand{\P}{\mathcal{P}}
\newcommand{\Q}{\mathbb{Q}}
\newcommand{\R}{\mathbb{R}}
\newcommand{\N}{\mathbb{N}}
\newcommand{\Z}{\mathbb{Z}}
\newcommand{\sph}{\mathsf{S}^\mathsf{1}}
\newcommand{\g}{>}
\newcommand{\l}{<}
\newcommand{\intd}{\,\mathsf{d}}
\newcommand{\Re}{\mathsf{Re}}
\newcommand{\area}{\mathop{\mathsf{Area}}}
\newcommand{\met}{\mathop{\mathsf{d}}}
\newcommand{\emptyset}{\varnothing}
\DeclareMathOperator{\borel}{\mathsf{Bor}}
\DeclareMathOperator{\baire}{\mathsf{Baire}}
\newcommand{\orb}{\mathop{\mathsf{orb}}}
\newcommand{\symdiff}{\mathop\triangle}
\newcommand{\lp}[1][2]{\operatorname{\mathscr{L}^{\mathsf{#1}}}}
\newcommand{\Lp}[1][2]{\operatorname{\mathsf{L}^{\!\mathsf{#1}}}}
\newcommand{\ent}{\operatorname{\mathsf{H}}}
\]
Week 11 Coursework Test
- For each $N \in \N$ write down a partition $\xi$ of $\{0,1\}^\N$ such that
\[
\ent(\xi) \ge N
\]
with respect to the fair coin measure.
-
- Describe the sequences that belong to
\[
Y = \{ x \in \{0,1\}^\N : x(n) = 0 \Rightarrow x(n+1) = 0 \}
\]
and calculate the entropy of the shift map with respect to every shift-invariant probability measure on $\{0,1\}^\N$ with the property that $\mu(Y) = 1$.
- For the Markov chain defined by the matrix
\[
\begin{bmatrix} 1 & 1 & 1 \\ 1 & 0 & 0 \\ 1 & 0 & 0 \end{bmatrix}
\]
calculate the maximum possible value of the entropy for an invariant measure.