Abstract
We construct a counterexample to a conjectured inequality L ≤ 2D, relating the diameter D and the least length L of a nontrivial closed geodesic, for a Riemannian metric on the 2-sphere. The construction relies on Guillemin's theorem concerning the existence of Zoll surfaces integrating an arbitrary infinitesimal odd deformation of the round metric. Thus the round metric is not optimal for the ratio L/D.
Original language | English |
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Pages (from-to) | 1-10 |
Number of pages | 10 |
Journal | Geometric and Functional Analysis |
Volume | 19 |
Issue number | 1 |
DOIs | |
State | Published - May 2009 |
Bibliographical note
Funding Information:Keywords and phrases: Closed geodesic, diameter, Guillemin deformation, sphere, systole, Zoll surface AMS Mathematics Subject Classification: 53C23, 53C22 F.B. supported by the Swiss National Science Foundation. C.C. supported by NSF grants DMS 02-02536 and DMS 07-04145. M.K. supported by the Israel Science Foundation (grants 84/03 and 1294/06)
Funding
Keywords and phrases: Closed geodesic, diameter, Guillemin deformation, sphere, systole, Zoll surface AMS Mathematics Subject Classification: 53C23, 53C22 F.B. supported by the Swiss National Science Foundation. C.C. supported by NSF grants DMS 02-02536 and DMS 07-04145. M.K. supported by the Israel Science Foundation (grants 84/03 and 1294/06)
Funders | Funder number |
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National Science Foundation | DMS 07-04145, DMS 02-02536 |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | |
Israel Science Foundation | 1294/06, 84/03 |
Keywords
- Closed geodesic
- Diameter
- Guillemin deformation
- Sphere
- Systole
- Zoll surface