Besse conjecture with positive isotropic curvature

The critical point equation arises as a of the total scalar curvature functional defined on space constant metrics unit volume compact manifold. In this equation, there exists function f manifold that satisfies following $$\begin{aligned} (1+f)\mathrm{Ric} = Ddf + \frac{nf +n-1}{n(n-1)}sg. \end{aligned}$$ It has been conjectured if (g, f) is solution then g Einstein and so (M, g) isometric to standard sphere. paper, we show conjecture true given Riemannian metric positive isotropic curvature.