Transverse rational curves and the homogeneity of contact Fano manifolds

Source abstract

We prove that every smooth complex projective contact Fano manifold is homogeneous under its connected contact automorphism group. The argument extends and simplifies the incidence method of our earlier proof of the LeBrun--Salamon conjecture. After the classical reductions, balanced transverse rational maps through every point yield tangent sections extending across the nodal boundary. These establish irreducibility and nonlinearity of the general variety of minimal rational tangents associated with contact lines, enabling Hwang's descent theorem to produce global vector fields generating the tangent bundle. Consequences include very ampleness of the contact line bundle, embeddedness of every balanced rational map, Kähler--Einstein existence, K-polystability, and the LeBrun--Salamon conjecture.