arXiv · math/0210159
We classify the complete metrics of nonnegative sectional curvature on M^2xR^2, where M^2 is any compact 2-manifold.
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Detlef Gromoll, Kristopher Tapp. 2002-10-10. Nonnegatively curved metrics on S^2xR^2. https://arxiv.org/abs/math/0210159
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