Schwarzschild 1/r singularity is not permissible in ghost-free quadratic-curvature infinite-derivative gravity

In this paper, we will study the complete equations of motion for a ghost-free quadratic-curvature infinite-derivative gravity. We will argue that within the scale of nonlocality, a Schwarzschild-type singular metric solution is not permissible. Therefore, the Schwarzschild-type vacuum solution which is a prediction in Einstein-Hilbert gravity may not persist within the region of nonlocality. We will also show that just quadratic-curvature gravity, without infinite derivatives, always allows Schwarzschild-type singular metric solution.