Comptes Rendus. Mathématique (Dec 2022)
Harmonic vector fields and the Hodge Laplacian operator on Finsler geometry
Abstract
We first present the natural definitions of the horizontal differential, the divergence (as an adjoint operator) and a $p$-harmonic form on a Finsler manifold. Next, we prove a Hodge-type theorem for a Finsler manifold in the sense that a horizontal $p$-form is harmonic if and only if the horizontal Laplacian vanishes. This viewpoint provides a new appropriate natural definition of harmonic vector fields in Finsler geometry. This approach leads to a Bochner–Yano type classification theorem based on the harmonic Ricci scalar. Finally, we show that a closed orientable Finsler manifold with a positive harmonic Ricci scalar has zero Betti number.