Displacement interpolation
= Displacement interpolation
{title2=$\mu_t=((1-t)\operatorname{Id}+tT)_\#\mu$}
In Euclidean space, push an optimal <transport plan> $\pi$ forward by $(x,y)\mapsto(1-t)x+ty$. The resulting <probability measures> form a constant speed curve for the <p-Wasserstein distance>:
$$
W_p(\mu_s,\mu_t)=|t-s|W_p(\mu_0,\mu_1).
$$
If the plan is induced by a <transport map> $T$, this becomes the displayed title formula.