The notion of super weak compactness for subsets of Banach spaces is a strengthening of the weak compactness that can be described as a local version of super-reflexivity. A recent result of K. Tu [32] which establishes that the closed convex hull of a super weakly compact set is super weakly compact has removed the main obstacle to further development of the theory. In this paper we provide a variety of results around super weak compactness in order to show the great scope of this notion. We also give non linear characterizations of super weak compactness in terms of the (non) embeddability of special trees and graphs. We conclude with a few relevant examples of super weakly compact sets in non super-reflexive Banach spaces.
La notion de partie super faiblement compacte d’un espace de Banach est un renforcement de la compacité faible qui peut être décrite comme une version locale de la super réflexivité. Un résultat récent de K. Tu qui assure que l’enveloppe convexe fermée d’un ensemble super faiblement compact est super faiblement compacte a supprimé le principal obstacle au développement de cette théorie. Dans cet article, nous fournissons une variété de résultats autour de la super faible compacité pour montrer la grande portée de cette notion. Nous donnons aussi des caractérisations non linéaires de la super faible compacité en termes de (non) plongement de certains arbres et graphes. Nous concluons avec quelques exemples significatifs de parties super faiblement compactes d’espaces de Banach non super réflexifs.
Revised:
Accepted:
Published online:
Keywords: super weakly compact sets, ultrapowers, uniformly convex sets, non linear embeddings in Banach spaces
Mots-clés : Ensembles super faiblement compacts, ultrapuissances, ensembles uniformément convexes, plongements non linéaires dans les espaces de Banach
Lancien, Gilles 1; Raja, Matias 2
@article{AIF_2022__72_3_1305_0, author = {Lancien, Gilles and Raja, Matias}, title = {Nonlinear aspects of super weakly compact sets}, journal = {Annales de l'Institut Fourier}, pages = {1305--1328}, publisher = {Association des Annales de l{\textquoteright}institut Fourier}, volume = {72}, number = {3}, year = {2022}, doi = {10.5802/aif.3488}, language = {en}, url = {https://aif.centre-mersenne.org/articles/10.5802/aif.3488/} }
TY - JOUR AU - Lancien, Gilles AU - Raja, Matias TI - Nonlinear aspects of super weakly compact sets JO - Annales de l'Institut Fourier PY - 2022 SP - 1305 EP - 1328 VL - 72 IS - 3 PB - Association des Annales de l’institut Fourier UR - https://aif.centre-mersenne.org/articles/10.5802/aif.3488/ DO - 10.5802/aif.3488 LA - en ID - AIF_2022__72_3_1305_0 ER -
%0 Journal Article %A Lancien, Gilles %A Raja, Matias %T Nonlinear aspects of super weakly compact sets %J Annales de l'Institut Fourier %D 2022 %P 1305-1328 %V 72 %N 3 %I Association des Annales de l’institut Fourier %U https://aif.centre-mersenne.org/articles/10.5802/aif.3488/ %R 10.5802/aif.3488 %G en %F AIF_2022__72_3_1305_0
Lancien, Gilles; Raja, Matias. Nonlinear aspects of super weakly compact sets. Annales de l'Institut Fourier, Volume 72 (2022) no. 3, pp. 1305-1328. doi : 10.5802/aif.3488. https://aif.centre-mersenne.org/articles/10.5802/aif.3488/
[1] Topics in Banach Space Theory, Graduate Texts in Mathematics, 233, Springer, 2016 | DOI | Zbl
[2] The probabilistic method, Wiley-Interscience Series in Discrete Mathematics and Optimization, John Wiley & Sons, 2016 | Zbl
[3] Weak-continuity of Jordan triple products and its applications, Math. Scand., Volume 59 (1986) no. 2, pp. 177-191 | DOI | MR | Zbl
[4] Metrical characterization of super-reflexivity and linear type of Banach spaces, Arch. Math., Volume 89 (2007) no. 5, pp. 419-429 | DOI | MR | Zbl
[5] Opérateurs uniformément convexifiants, Stud. Math., Volume 57 (1976) no. 2, pp. 103-139 | DOI | Zbl
[6] Introduction to Banach spaces and their geometry, North-Holland Mathematics Studies, 68, North-Holland, 1982 | Zbl
[7] Geometric Nonlinear Functional Analysis, Colloquium Publications, 48, American Mathematical Society, 2000 | Zbl
[8] Preduals of JBW-triples are -Plichko spaces, Q. J. Math., Volume 69 (2018) no. 2, pp. 655-680 | DOI | MR | Zbl
[9] The metrical interpretation of super-reflexivity in Banach spaces, Isr. J. Math., Volume 56 (1986), pp. 222-230 | DOI | Zbl
[10] Metric characterizations of super weakly compact operators, Stud. Math., Volume 239 (2017) no. 2, pp. 175-188 | DOI | MR | Zbl
[11] Approximation of Lipschitz functions by -convex functions in Banach spaces, Isr. J. Math., Volume 106 (1998), pp. 269-284 | MR | Zbl
[12] On super weak compactness of subsets and its equivalences in Banach spaces, J. Convex Anal., Volume 25 (2018) no. 3, pp. 899-926 | MR | Zbl
[13] On super-weakly compact sets and uniformly convexifiable sets, Stud. Math., Volume 199 (2010) no. 2, pp. 145-169 | DOI | MR | Zbl
[14] Smoothness and renormings in Banach spaces, Pitman Monographs and Surveys in Pure and Applied Mathematics, 64, Longman Scientific & Technical, 1993 | Zbl
[15] Geometry of Banach spaces. Selected topics, Lecture Notes in Mathematics, 485, Springer, 1975 | DOI | MR | Zbl
[16] Banach Space Theory. The Basis for Linear and Nonlinear Analysis, CMS Books in Mathematics, Springer, 2011 | Zbl
[17] Measures of weak non-compactness in preduals of von Neumann algebras and JBW-triples, J. Funct. Anal., Volume 278 (2020) no. 1, 108300 | MR | Zbl
[18] Weak compactness and reflexivity, Isr. J. Math., Volume 2 (1964), pp. 101-119 | DOI | MR | Zbl
[19] Diamond graphs and super-reflexivity, J. Topol. Anal., Volume 1 (2009) no. 2, pp. 177-189 | DOI | MR | Zbl
[20] Unconditional convergence of series in uniformly convex spaces, Usp. Mat. Nauk, Volume 11 (1956), pp. 185-190 | MR
[21] Contractive projections on Jordan -algebras and generalizations, Math. Scand., Volume 54 (1984) no. 1, pp. 95-100 | DOI | MR | Zbl
[22] Yet another short proof of Bourgain’s distortion estimate for embedding of trees into uniformly convex Banach spaces, Isr. J. Math., Volume 200 (2014) no. 1, pp. 419-422 | DOI | MR | Zbl
[23] Théorie de l’indice et problèmes de renormage en géométrie des espaces de Banach, Ph. D. Thesis, Université Paris VI, Paris, France (1992)
[24] On uniformly convex and uniformly Kadec–Klee renormings, Serdica Math. J., Volume 21 (1995) no. 1, pp. 1-18 | MR | Zbl
[25] Martingales with values in uniformly convex spaces, Isr. J. Math., Volume 20 (1975), pp. 326-350 | DOI | MR | Zbl
[26] Existence theorems and convergence of minimizing sequences in extremum problems with restrictions, Sov. Math., Dokl., Volume 7 (1966), pp. 72-75 | Zbl
[27] Finitely dentable functions, operators and sets, J. Convex Anal., Volume 15 (2008) no. 2, pp. 219-233 | MR | Zbl
[28] Super WCG Banach spaces, J. Math. Anal. Appl., Volume 439 (2016) no. 1, pp. 183-196 | DOI | MR | Zbl
[29] Cesàro convergent sequences in the Mackey topology, Mediterr. J. Math., Volume 16 (2019) no. 5, 117 | Zbl
[30] A coding of bundle graphs and their embeddings into Banach spaces, Mathematika, Volume 64 (2018) no. 3, pp. 847-874 | DOI | MR | Zbl
[31] Sur les suites faiblement convergentes dans l’espace , Stud. Math., Volume 25 (1965), pp. 337-341 | DOI | MR | Zbl
[32] Convexification of super weakly compact sets and measure of super weak noncompactness, Proc. Am. Math. Soc., Volume 149 (2021) no. 6, pp. 2531-2538 | MR | Zbl
Cited by Sources: