Timeline for Example metrics for exotic R4
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
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| Sep 17, 2019 at 13:10 | comment | added | alvarezpaiva | As far as I know: it is not known whether an exotic sphere admits a Riemannian (or even Finsler) metric all of whose geodesics are closed. This is a question of Gromoll, if I remember correctly. If a smooth $R^4$ admits a complete metric of zero curvature, then by Cartan-Hadamard it is diffeomorphic to the standard $R^4$. | |
| Sep 16, 2019 at 14:50 | comment | added | Francesco Polizzi | see also mathoverflow.net/questions/89415/best-metrics-on-exotic-r4 | |
| Sep 16, 2019 at 14:08 | comment | added | Bombyx mori | I feel confused with the professor name as well. Maybe there is a physicist named Kirby? | |
| Sep 16, 2019 at 13:56 | history | edited | YCor |
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| Sep 16, 2019 at 13:42 | comment | added | David Roberts♦ | While I applaud your interest, I'm not sure the user name you have chosen is that wise, unless your name happens to be Kirby. Professor Robion Kirby is a well-known low-dimensional topologist who has worked on 4-manifolds! | |
| Sep 16, 2019 at 13:25 | history | asked | Kirby | CC BY-SA 4.0 |