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We prove that the least area of noncontractible immersed spheres is no greater than 4 π 4 in any oriented manifold with dimension n + 2 ≤ 7 n+2 7 which satisfies R ≥ 2 R 2 and admits a continuous map to S 2 × T n S² Tⁿ with nonzero degree. We also prove a rigidity result for the equality case. This can be viewed as a generalization of the result in Comm. Anal. Geom. 18 (2010), pp. 821–830 to higher dimensions.
Jintian Zhu (Wed,) studied this question.