In the n = 1 special case, the Fubini–Study metric has constant sectional curvature identically equal to 4, according to the equivalence with the 2-sphere's round metric (which given a radius R has sectional curvature 1 / R 2 ). However, for n > 1, the Fubini–Study metric does not have constant curvature. Its sectional curvature is instead given by the equation