Abstract
It is shown in this paper that the notion of α-dense curve in a bounded set of a metric space produces a degree of nondensifiability which extended to convex hulls of bounded sets in a Banach space generates a measure of noncompactness (briefly MNC) Φ that we will call degree of convex nondensifiability. We also prove that Φ dominates any other MNC and, in particular, dominates the MNC of Hausdorff of the best possible form in infinite dimensional Banach spaces.
References
- R. R. Akhmerov, M. I. Kamenskii, A. S. Potapov, A. E. Rodkina, B. N. Sadovskii: Measures of Noncompactness and Condensing Operators, Birkhäuser, Basel (1992).https://doi.org/10.1007/978-3-0348-5727-7Google Scholar
- F. Albiac, N. J. Kalton: Topics in Banach Spaces Theory, Springer, New York (2006).Google Scholar
- J. M. Ayerbe Toledano, T. Domínguez Benavides, G. López Acedo: Measures of Noncompactness in Metric Fixed Point Theory, Birkhäuser, Basel (1997).https://doi.org/10.1007/978-3-0348-8920-9Google Scholar
- J. Banas, K. Goebel: Measures of Noncompactness in Banach Spaces, Marcel Dekker, New York (1980).Google Scholar
- J. Banas, J. Rivero: On measures of weak noncompactness, Ann. Mat. Pura Appl., IV. Ser. 151 (1988) 213–224.https://doi.org/10.1007/BF01762795Google Scholar
- N. L. Carothers: A Short Course on Banach Space Theory, Cambridge Univ. Press, Cambridge (2005).https://doi.org/10.1017/CBO9780511614057Google Scholar
- G. Darbo: Punti uniti in transformazioni a codomio non compatto, Rend. Sem. Mat. Univ. Padova 24 (1955) 84–92.Google Scholar
- F. S. De Blasi: On a property of the unit sphere in a Banach space, Colloq. Math. 65 (1977) 333–343.https://doi.org/10.1090/S0002-9939-1977-0447730-0Google Scholar
- I. Gohberg, L. S. Goldenshtein, A. S. Markus: Investigation on some properties of bounded linear operators in connection with their q-norms, Uchen. Zap. Kishinev Gos. Univ. 29 (1957) 29–36.Google Scholar
- J. G. Hocking, G. S. Young: Topology, Addison-Wesley, Reading (1961).Google Scholar
- R. B. Holmes: Geometric Functional Analysis and its Applications, Springer, New York (1975).https://doi.org/10.1007/978-1-4684-9369-6Google Scholar
- V. I. Istratescu: Fixed Point Theory, D. Reidel, Dordrecht (1981).https://doi.org/10.1007/978-94-009-8177-5Google Scholar
- J. L. Kelley: General Topology, D. van Nostrand, New York (1955).Google Scholar
- K. Kuratowski: Sur les espaces complets, Fundam. Math. 15 (1930) 301–309.https://doi.org/10.4064/fm-15-1-301-309Google Scholar
- J. Mallet-Paret, R. D. Nussbaum: Inequivalent measures of noncompactness and the radius of the essential spectrum, Proc. Amer. Math. Soc. 139(3) (2011) 917–930.https://doi.org/10.1090/S0002-9939-2010-10511-7Google Scholar
- G. Mora, Y. Cherruault: Characterization and generation of α-dense curves, Comput. Math. Appl. 33(9) (1997) 83–91.https://doi.org/10.1016/S0898-1221(97)00067-9Google Scholar
- G. Mora, Y. Cherruault: An approximation method for the optimization of continuous functions of n variables by densifying their domains, Kybernetes 28(2–3) (1999) 164–180.https://doi.org/10.1108/03684929910258798Google Scholar
- G. Mora: Optimization by space-densifying curves as a natural generalization of the alienor method, Kybernetes 29(5–6) (2000) 746–754.https://doi.org/10.1108/03684920010333170Google Scholar
- G. Mora, J. A. Mira: Alpha-dense curves in infinite dimensional spaces, Int. J. Pure Appl. Math. 5(4) (2003) 437–449.Google Scholar
- G. Mora, D. A. Redtwitz: Densifiable metric spaces, Rev. R. Acad. Cienc. Exactas Fs. Nat., Ser. A Mat., RACSAM 105 (2011) 71–83.https://doi.org/10.1007/s13398-011-0005-yGoogle Scholar
- H. Sagan: Space Filling Curves, Springer, New York (1994).https://doi.org/10.1007/978-1-4612-0871-6Google Scholar
- E. Zeidler: Nonlinear Functional Analysis and its Applications, Springer, New York (1986).https://doi.org/10.1007/978-1-4612-4838-5Google Scholar
Suggested citation
Published by Heldermann Verlag, 2015. Rights now held by Banach Press LLC.
