We find a criterion for uniform rotundity in every direction (URED) of Calderón-Lozanovskii sequence spaces solving Problem XII from S. T. Chen, Y. A. Cui, H. Hudzik and T. F. Wang ["On some solved and unsolved problems in geometry of certain classes of Banach function spaces", in: Unsolved Problems on Mathematics for the 21st Century, J. M. Abe & Tanaka (eds.), IOS Press (2001)]. In order to do it, we study properties of the directed modulus of convexity of Banach spaces. Next we introduce and study new notions such as uniform rotundity in every interval (UREI) and uniform monotonicity in every interval (UMEI). They are crucial to get the main criterion, that is a Köthe sequence space is UREI iff it is URED and order continuous. Then we show the important (for further investigations) characterization of the property UREI on the positive cone of Köthe sequence space. Applying that we prove the characterization mentioned at the beginning of the abstract. As a corollary, we obtain the criterion for URED of Orlicz-Lorentz sequence spaces, which has not been proved until now.

Contact details are reproduced from the original publication and may be historical.

Paweł Kolwicz

Inst. of Mathematics, Poznań University of Technology, Piotrowo 3A, 60-965 Poznań, Poland

kolwicz@math.put.poznan.pl

Ryszard Płuciennik

Inst. of Mathematics, Poznań University of Technology, Piotrowo 3A, 60-965 Poznań, Poland

rplucien@math.put.poznan.pl
  1. M. A. Akcoglu, L. Sucheston: On uniform monotonicity of norms and ergodic theorems in function spaces, Rend. Circ. Mat. Palermo, II. Ser., Suppl. 8 (1985) 325–335.Google Scholar
  2. T. Ando: On the continuity of the norms, Proc. Japan Acad. 33 (1957) 429–434.https://doi.org/10.3792/pja/1195524951Google Scholar
  3. G. Birkhoff: Lattice Theory, American Mathematical Society, Providence (1967).Google Scholar
  4. J. Cerdá, H. Hudzik, A. Kamińska, M. Mastyło: Geometric properties of symmetric spaces with applications to Orlicz-Lorentz spaces, Positivity 2 (1998) 311–337.https://doi.org/10.1023/A:1009728519669Google Scholar
  5. J. Cerdá, H. Hudzik, M. Mastyło: On the geometry of some Calderón-Lozanovskiĭ interpolation spaces, Indag. Math., New Ser. 6(1) (1995) 35–49.https://doi.org/10.1016/0019-3577(95)98199-LGoogle Scholar
  6. S. Chen, Y. Cui, H. Hudzik, B. Sims: Geometric properties related to fixed point theory in some Banach function lattices, in: Handbook of Metric Fixed Point Theory, W. A. Kirk et al. (ed.), Kluver Akademic Publishers, Dordrecht (2001) 339–389.https://doi.org/10.1007/978-94-017-1748-9_12Google Scholar
  7. S. Chen, Y. Cui, H. Hudzik, T. Wang: On some solved and unsolved problems in geometry of certain classes of Banach function spaces, in: Unsolved Problems on Mathematics for the 21st Century, J. M. Abe et al. (ed.), IOS Press, Amsterdam (2001) 239–259.Google Scholar
  8. J. A. Clarkson: Uniformly convex spaces, Trans. Amer. Math. Soc. 40 (1936) 396–414.https://doi.org/10.1090/S0002-9947-1936-1501880-4Google Scholar
  9. Y. Cui, H. Hudzik, L. Szymaszkiewicz, T. Wang: Criteria for monotonicity properties in Musielak-Orlicz spaces equipped with the Amemiya norm, J. Math. Anal. Appl. 303 (2005) 376–390.https://doi.org/10.1016/j.jmaa.2004.07.026Google Scholar
  10. T. Dominguez, H. Hudzik, G. López, M. Mastyło, B. Sims: Complete characterization of Kadec-Klee properties in Orlicz spaces, Houston J. Math. 29(4) (2003) 1027–1044.Google Scholar
  11. P. N. Dowling, C. J. Lennard, B. Turett: Reflexivity and the fixed point property for nonexpansive maps, J. Math. Anal. Appl. 200 (1996) 653–662.https://doi.org/10.1006/jmaa.1996.0229Google Scholar
  12. P. Foralewski, H. Hudzik: Some basic properties of generalized Calderón-Lozanovskiĭ spaces, Collect. Math. 48(4-6) (1997) 523–538.Google Scholar
  13. P. Foralewski, H. Hudzik: On some geometrical and topological properties of generalized Calderón-Lozanovskiĭ sequence spaces, Houston J. Math 25(3) (1999) 523–542.Google Scholar
  14. P. Foralewski, P. Kolwicz: Local uniform rotundity in Calderón-Lozanovskiĭ spaces, J. Convex Analysis 14(2) (2007) 395–412.https://doi.org/10.68381/jca14026Google Scholar
  15. A. L. Garkavi: The best possible net and the best possible cross-section of a set in a normed space, Izv. Akad. Nauk SSSR, Ser. Mat. 26 (1962) 87–106 (in Russian); Amer. Math. Soc., Transl., II. Ser. 39 (1964) 111–132 (in English).Google Scholar
  16. H. Hudzik, A. Kamińska: Monotonicity properties of Lorentz spaces, Proc. Amer. Math. Soc. 123(9) (1995) 2715–2721.https://doi.org/10.1090/S0002-9939-1995-1273499-7Google Scholar
  17. H. Hudzik, A. Kamińska, M. Mastyło: Geometric properties of some Calderón-Lozanovskiĭ spaces and Orlicz-Lorentz spaces, Houston J. Math. 22 (1996) 639–663.Google Scholar
  18. H. Hudzik, A. Kamińska, M. Mastyło: Monotonicity and rotundity properties in Banach lattices, Rocky Mt. J. Math. 30(3) (2000) 933–949.https://doi.org/10.1216/rmjm/1021477253Google Scholar
  19. A. Kamińska: Some remarks on Orlicz-Lorentz spaces, Math. Nachr. 147 (1990) 29–38.https://doi.org/10.1002/mana.19901470104Google Scholar
  20. A. Kamińska: Uniform convexity of generalized Lorentz spaces, Arch. Math. 56 (1991) 181–188.https://doi.org/10.1007/BF01200349Google Scholar
  21. A. Kamińska, B. Turett: Some remarks on moduli of rotundity in Banach spaces, Bull. Pol. Acad. Sci., Math. 36(5-6) (1988) 219–223.Google Scholar
  22. L. V. Kantorovich, G. P. Akilov: Functional Analysis, Nauka, Moscow (1984), (in Russian).Google Scholar
  23. W. A. Kirk: A fixed point theorem for mappings which do not increase distances, Amer. Math. Monthly 72 (1965) 1004–1008.https://doi.org/10.2307/2313345Google Scholar
  24. P. Kolwicz: Orthogonal uniform convexity in Köthe spaces and Orlicz spaces, Bull. Pol. Acad. Sci., Math. 50(4) (2002) 395–412.Google Scholar
  25. P. Kolwicz: Rotundity properties in Calderón-Lozanovskiĭ spaces, Houston J. Math. 31(3) (2005) 883–912.Google Scholar
  26. P. K. Lin: Köthe-Bochner Function Spaces, Birkhäuser, Boston (2004).https://doi.org/10.1007/978-0-8176-8188-3Google Scholar
  27. J. Lindenstrauss, L. Tzafriri: Classical Banach Spaces II, Springer, Berlin (1979).https://doi.org/10.1007/978-3-662-35347-9Google Scholar
  28. L. Maligranda: Orlicz Spaces and Interpolation, Seminars in Math. 5, Universidade Estadual de Campinas, Departamento de Matemática, Campinas (1989).Google Scholar
  29. M. Mastyło: Interpolation of linear operators in Calderón-Lozanovskiĭ spaces, Ann. Soc. Math. Pol., Ser. I, Commentat. Math. 26 (1986) 247–256.Google Scholar
  30. R. E. Megginson: An Introduction to Banach Space Theory, Springer, New York (1998).https://doi.org/10.1007/978-1-4612-0603-3Google Scholar
  31. A. Narloch: On some global and local geometric properties of Calderón-Lozanovskiĭ spaces, in: Orlicz Centenary Volume II, H. Hudzik (ed.) et al., Banach Center Publications 68, Polish Academy of Sciences, Institute of Mathematics, Warsaw (2005) 99–108.https://doi.org/10.4064/bc68-0-12Google Scholar
  32. M. A. Smith: Banach spaces that are uniformly rotund in weakly compact sets of directions, Canad. J. Math. 29(5) (1977) 963–970.https://doi.org/10.4153/CJM-1977-097-6Google Scholar
  33. M. A. Smith: Products of Banach spaces that are uniformly rotund in every direction, Pacific J. Math. 73(1) (1977) 215–219.https://doi.org/10.2140/pjm.1977.73.215Google Scholar
  34. M. A. Smith: Some examples concerning rotundity in Banach spaces, Math. Ann. 233 (1978) 155–161.https://doi.org/10.1007/BF01421923Google Scholar
  35. W. Wnuk: Banach Lattices with Order Continuous Norms, Polish Scientific Publisher PWN, Warsaw (1999).Google Scholar
  36. V. Zizler: On some rotundity and smoothness properties of Banach spaces, Dissertationes Math. Rozprawy Mat. 87 (1971).Google Scholar

P. Kolwicz, R. Płuciennik. “On Uniform Rotundity in Every Direction in Calderón-Lozanovskii Sequence Spaces.” Journal of Convex Analysis 14 (2007), No. 3, 621–645. https://doi.org/10.68381/jca14037