# Four-manifolds with positive isotropic curvature

@article{Hamilton1997FourmanifoldsWP, title={Four-manifolds with positive isotropic curvature}, author={Richard S. Hamilton}, journal={Communications in Analysis and Geometry}, year={1997}, volume={5}, pages={1-92} }

1. Positive Isotropic Curvature 2 (1) The Result 2 (2) The Algebra of Isotropic Curvature 4 2. Curvature Pinching 6 (1) Pinching Estimates which are Preserved 6 (2) Pinching Estimates which Improve 13 (3) Necklike Curvature Pinching 21 3. The Geometry of Necks 27 (1) Harmonic Parametrizations by Spheres 27 (2) Geometric Necks 30 (3) Curvature Necks 35 (4) The Fundamental Group 41 (5) Finding Necks 44 4. Surgery 47 (1) How to do Surgery 47 (2) Curvature Changes under Surgery .49 (3) Pinching…

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