 Kodaira embedding theorem

The Kodaira embedding theorem says that a compact complex manifold carrying a positive holomorphic line bundle is projective: sufficiently large tensor powers of the bundle have global holomorphic sections defining a holomorphic embedding into Complex projective space. Conversely, the restriction of $\mathcal{O}(1)$ gives a positive line bundle on every projective complex manifold.

The Kodaira embedding theorem is a fundamental result in complex differential geometry that provides a criterion for when a compact complex manifold can be embedded into projective space as a complex projective variety. The theorem tackles the interplay between the geometry of a compact complex manifold and the algebraic properties of holomorphic line bundles over it.