2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/108857This is essentially a note on Section 7 of Perelman's first paper on Ricci flow. We list some basic properties of the index form for Perelman's $ \mathcal{L} $-length, which are analogous to the ones in Riemannian case (with fixed metric), and observe that Morse's index theorem for Perelman's $\mathcal{L}$-length holds. As a corollary we get the finiteness of the number of the $\mathcal{L}$-conjugate points along a finite $\mathcal{L}$-geodesic.4 pagesDifferential Geometry53Ctext