On the James and von Neumann-Jordan constants in Banach spaces
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Abstract:
Recently Alonso, Martín and Papini conjectured that the value of the von Neumann-Jordan constant is less than or equal to that of the James constant. This paper presents an affirmative answer to such a conjecture. Moreover, we obtain a sharp estimate for the von Neumann-Jordan constant.References
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Additional Information
- Fenghui Wang
- Affiliation: Department of Mathematics, Luoyang Normal University, Luoyang 471022, People’s Republic of China
- Email: wfenghui@gmail.com
- Received by editor(s): February 28, 2009
- Received by editor(s) in revised form: July 1, 2009
- Published electronically: October 7, 2009
- Additional Notes: This work was supported by the Natural Science Foundation of the Department of Education, Henan (2008A110012), development programs in science and technology of Henan Province (092300410187), and the Youth Foundation of Luoyang Normal University (2008-QNJJ-011).
- Communicated by: Nigel J. Kalton
- © Copyright 2009
American Mathematical Society
The copyright for this article reverts to public domain 28 years after publication. - Journal: Proc. Amer. Math. Soc. 138 (2010), 695-701
- MSC (2000): Primary 46B20
- DOI: https://doi.org/10.1090/S0002-9939-09-10107-7
- MathSciNet review: 2557186