On caractérise l’octaédralité de la norme d’un espace Lipschitz libre par le biais d’une nouvelle propriété géométrique de l’espace métrique sous-jacent. Nous étudions les espaces métriques avec et sans cette propriété. Par exemple, les espaces sans cette propriété ne se plongent pas isométriquement dans et certains espaces de Banach similaires.
We characterise the octahedrality of Lipschitz-free space norm in terms of a new geometric property of the underlying metric space. We study the metric spaces with and without this property. Quite surprisingly, metric spaces without this property cannot be embedded isometrically into and similar Banach spaces.
Révisé le : 2017-05-04
Accepté le : 2017-06-14
Publié le : 2018-04-17
Classification : 46B04, 46B20, 46B85
Mots clés : Octaédralité, Espaces Lipschitz libres, Espaces métriques uniformément discrets
@article{AIF_2018__68_2_569_0, author = {Proch\'azka, Anton\'\i n and Rueda Zoca, Abraham}, title = {A characterisation of octahedrality in Lipschitz-free spaces}, journal = {Annales de l'Institut Fourier}, pages = {569--588}, publisher = {Association des Annales de l'institut Fourier}, volume = {68}, number = {2}, year = {2018}, doi = {10.5802/aif.3171}, language = {en}, url = {archive.numdam.org/item/AIF_2018__68_2_569_0/} }
Procházka, Antonín; Rueda Zoca, Abraham. A characterisation of octahedrality in Lipschitz-free spaces. Annales de l'Institut Fourier, Tome 68 (2018) no. 2, pp. 569-588. doi : 10.5802/aif.3171. http://archive.numdam.org/item/AIF_2018__68_2_569_0/
[1] Linear extensions, almost isometries, and diameter two, Extr. Math., Volume 30 (2015) no. 2, pp. 135-151 | MR 3496032 | Zbl 1365.46006
[2] Octahedrality in Lipschitz-free Banach spaces (to appear in Proc. Roy. Soc. Edinburgh Sect. A)
[3] Octahedral norms and convex combination of slices in Banach spaces, J. Funct. Anal., Volume 266 (2014) no. 4, pp. 2424-2435 | Article | MR 3150166 | Zbl 1297.46011
[4] Metric spaces of non-positive curvature, Grundlehren der Mathematischen Wissenschaften, Volume 319, Springer, 1999, xxii+643 pages | Article | MR 1744486 | Zbl 0988.53001
[5] Thick coverings for the unit ball of a Banach space, Houston J. Math., Volume 41 (2015) no. 1, pp. 177-186 | MR 3347943 | Zbl 1348.46012
[6] On the structure of Lipschitz-free spaces, Proc. Am. Math. Soc., Volume 144 (2016) no. 9, pp. 3833-3846 | Article | MR 3513542 | Zbl 1353.46004
[7] Isometric embedding of into Lipschitz-free spaces and into their duals, Proc. Am. Math. Soc., Volume 145 (2017) no. 8, pp. 3409-3421 | Article | MR 3652794 | Zbl 06734556
[8] Finitely additive measures and complementability of Lipschitz-free spaces (2017) (https://arxiv.org/abs/1703.08384)
[9] Characterization of metric spaces whose free space is isometric to , Bull. Belg. Math. Soc. - Simon Stevin, Volume 23 (2016) no. 3, pp. 391-400 http://projecteuclid.org/euclid.bbms/1473186513 | MR 3545460 | Zbl 1370.46009
[10] Banach space theory. The basis for linear and nonlinear analysis, CMS Books in Mathematics, Springer, 2011, xiv+820 pages | Article | MR 2766381 | Zbl 1229.46001
[11] Convexity, Optimization and Geometry of the Ball in Banach Spaces (2017) (Ph. D. Thesis)
[12] Some topological and geometrical structures in Banach spaces, Mem. Am. Math. Soc., Volume 70 (1987) no. 378, iv+116 pages | Article | MR 912637 | Zbl 0651.46017
[13] Tree metrics and their Lipschitz-free spaces, Proc. Am. Math. Soc., Volume 138 (2010) no. 12, pp. 4311-4320 | Article | MR 2680057 | Zbl 1222.46010
[14] Metric characterization of first Baire class linear forms and octahedral norms, Stud. Math., Volume 95 (1989) no. 1, pp. 1-15 | Article | MR 1024271 | Zbl 0698.46011
[15] A survey on Lipschitz-free Banach spaces, Commentat. Math., Volume 55 (2015) no. 2, pp. 89-118 | MR 3518958 | Zbl 1358.46015
[16] The ball topology and its applications, Banach space theory (Iowa City, IA, 1987) (Contemporary Mathematics) Volume 85, American Mathematical Society, 1989, pp. 195-237 | Article | MR 983386 | Zbl 0676.46003
[17] Lipschitz-free Banach spaces, Stud. Math., Volume 159 (2003) no. 1, pp. 121-141 | Article | MR 2030906 | Zbl 1059.46058
[18] On duality of diameter 2 properties, J. Convex Anal., Volume 22 (2015) no. 2, pp. 465-483 | MR 3346197 | Zbl 1337.46007
[19] The Daugavet property for spaces of Lipschitz functions, Math. Scand., Volume 101 (2007) no. 2, pp. 261-279 (corrigendum ibid. 104 (2009), no. 2, p. 319) | Article | MR 2379289 | Zbl 1177.46010
[20] Almost Fréchet differentiability of Lipschitz mappings between infinite-dimensional Banach spaces, Proc. Lond. Math. Soc., Volume 84 (2002) no. 3, pp. 711-746 | Article | MR 1888429 | Zbl 1023.46046
[21] Lipschitz quotients from metric trees and from Banach spaces containing , J. Funct. Anal., Volume 194 (2002) no. 2, pp. 332-346 | Article | MR 1934607 | Zbl 1013.46012
[22] Types and -subspaces, Texas functional analysis seminar 1982–1983 (Austin, Tex.) (Longhorn Notes), University of Texas, 1983, pp. 123-137 | MR 832221 | Zbl 1288.46018
[23] Extension of range of functions, Bull. Am. Math. Soc., Volume 40 (1934) no. 12, pp. 837-842 | Article | MR 1562984 | Zbl 0010.34606
[24] Geometric theory of Banach spaces. II. Geometry of the unit ball, Uspehi Mat. Nauk, Volume 26 (1971) no. 6(162), pp. 73-149 | MR 0420226 | Zbl 0229.46017
[25] Lipschitz-free spaces and Schur properties, J. Math. Anal. Appl., Volume 453 (2017) no. 2, pp. 894-907 | Article | Zbl 06728495
[26] Some isometric properties of subspaces of function spaces, Mediterr. J. Math., Volume 10 (2013) no. 4, pp. 1905-1915 | Article | MR 3119340 | Zbl 1286.46013