Brown–York mass and positive scalar curvature II: Besse’s conjecture and related problems

The Besse’s conjecture was posed on the well-known book Einstein manifolds by Arthur L. Besse, which describes critical points of Hilbert–Einstein functional with constraint of unit volume and constant scalar curvature. In this article, we show that there is an interesting connection between Besse’s conjecture and positive mass theorem for Brown–York mass. With the aid of positive mass theorem, we investigate the geometric structure of CPE manifolds and this provides us further understandings about Besse’s conjecture. As a related topic, we also discuss corresponding results for V-static metrics.