Harnack inequalities for the curve shortening flow

We offer an algorithmic approach for determining Harnack quantities for the curve shortening flow and we show how, following this procedure, one can obtain Hamilton’s Harnack inequality for this flow $\kappa_t + \frac{1}{2t}\kappa \geq \frac{\kappa_s^2}{\kappa}$,where$\kappa$ is the curvature of the curve being deformed by the flow.