Longtime existence of K\"ahler Ricci flow and holomorphic sectional curvature

In this work, we obtain a existence criteria for the longtime K"ahler Ricci flow solution. Using the existence result, we generalize a result by Wu-Yau on the existence of K"ahler Einstein metric to the case with possibly unbounded curvature. Moreover, the K"ahler Einstein metric with negative scalar curvture must be unique up to scaling.