Geometric structure and existence of reducible spherical conical metrics
摘要
We study reducible spherical conical metrics on compact Riemann surfaces–conformal metrics The existence of reducible spherical conical metrics on a compact Riemann surface is equivalent to the existence of an Abelian differential of the third kind with specified analytic properties. Any compact Riemann surface admitting such a metric decomposes into finitely many pieces via suitable geodesic cuts connecting conical singularities and some smooth points. Each piece is isometric to a portion obtained by cutting a football along a geodesic that joins the two conical singularities. We give an explicit angle condition that characterizes the existence of such metrics.