\tikzstyle{block} = [rectangle, rounded corners=3mm, very thick, font=\small, draw=blue!50!white, fill=blue!10!white]
\tikzstyle{decision} = [diamond, shape aspect=2.5, very thick, font=\small, draw=red!50!white, fill=red!10!white, inner sep=0mm]

\begin{tikzpicture}
\node[block] (step1) at (0, 0) {\parbox[c][\height][c]{4cm}{\centering Choose an initial measure $\mu \in \mathcal P(\mathbb S^{d-1})$ for $u(0)$.}};
\node[block] (step2) at (0, -1.8) {\parbox[c][\height][c]{4cm}{\centering Compute $N$ optimal trajectories using \eqref{SystGammaURegular}.}};
\node[decision] (test) at (0, -4.5) {\parbox[c][\height][c]{4cm}{\centering Do all trajectories with positive mass arrive at $\partial\Omega$ at the same time?}};
\node[block] (end) at (0, -7.5) {\parbox[c][\height][c]{4cm}{\centering $\mu$ yields an equilibrium.}};
\node[block] (loop) at (-5, -2.5) {\parbox[c][\height][c]{4cm}{\centering Choose another $\mu$, putting more mass on those who arrived early and less mass on those who arrived late.}};
\node at (7, 0) {};
\draw[thick, -Stealth] (step1) -- (step2);
\draw[thick, -Stealth] (step2) -- (test);
\draw[thick, -Stealth] (test) -- node[midway, right] {\small Yes} (end);
\draw[thick, -Stealth] (test) -- node[midway, below] {\small No} +(-5, 0) -- (loop);
\draw[thick, -Stealth] (loop) -- (-5, -0.7) -- (0, -0.7);
\end{tikzpicture}