Complex analysis/Functional analysis
Density of disk algebra functions in de Branges–Rovnyak spaces
[Densité des fonctions dans l'algèbre du disque dans les espaces de de Branges–Rovnyak]
Comptes Rendus. Mathématique, Tome 355 (2017) no. 8, pp. 871-875.

On démontre que les fonctions analytiques dans le disque unité et continues dans le disque fermé sont denses dans l'espace de Branges–Rovnyak généré par un point extrémal de la boule unité de H. En utilisant aussi des théorèmes précédents, il résulte que cette classe de fonctions est dense dans un espace de Branges–Rovnyak quelconque.

We prove that functions analytic in the unit disk and continuous up to the boundary are dense in the de Branges–Rovnyak spaces induced by the extreme points of the unit ball of H. Together with previous theorems, it follows that this class of functions is dense in any de Branges–Rovnyak space.

Reçu le :
Accepté le :
Publié le :
DOI : 10.1016/j.crma.2017.07.015
Aleman, Alexandru 1 ; Malman, Bartosz 1

1 Centre for Mathematical Sciences, Lund University, P.O Box 118, SE-22100 Lund, Sweden
@article{CRMATH_2017__355_8_871_0,
     author = {Aleman, Alexandru and Malman, Bartosz},
     title = {Density of disk algebra functions in de {Branges{\textendash}Rovnyak} spaces},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {871--875},
     publisher = {Elsevier},
     volume = {355},
     number = {8},
     year = {2017},
     doi = {10.1016/j.crma.2017.07.015},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.crma.2017.07.015/}
}
TY  - JOUR
AU  - Aleman, Alexandru
AU  - Malman, Bartosz
TI  - Density of disk algebra functions in de Branges–Rovnyak spaces
JO  - Comptes Rendus. Mathématique
PY  - 2017
SP  - 871
EP  - 875
VL  - 355
IS  - 8
PB  - Elsevier
UR  - http://www.numdam.org/articles/10.1016/j.crma.2017.07.015/
DO  - 10.1016/j.crma.2017.07.015
LA  - en
ID  - CRMATH_2017__355_8_871_0
ER  - 
%0 Journal Article
%A Aleman, Alexandru
%A Malman, Bartosz
%T Density of disk algebra functions in de Branges–Rovnyak spaces
%J Comptes Rendus. Mathématique
%D 2017
%P 871-875
%V 355
%N 8
%I Elsevier
%U http://www.numdam.org/articles/10.1016/j.crma.2017.07.015/
%R 10.1016/j.crma.2017.07.015
%G en
%F CRMATH_2017__355_8_871_0
Aleman, Alexandru; Malman, Bartosz. Density of disk algebra functions in de Branges–Rovnyak spaces. Comptes Rendus. Mathématique, Tome 355 (2017) no. 8, pp. 871-875. doi : 10.1016/j.crma.2017.07.015. http://www.numdam.org/articles/10.1016/j.crma.2017.07.015/

[1] Aleksandrov, A.B. Invariant subspaces of shift operators. An axiomatic approach, Zap. Nauchn. Sem. Leningrad. Otdel. Mat. Inst. Steklov. (LOMI), Volume 113 (1981), pp. 7-26 (264, English translation in J. Sov. Math., 22, 1983, pp. 1695-1708)

[2] Aleman, A.; Feldman, N.S.; Ross, W.T. The Hardy space of a slit domain, Frontiers in Mathematics, Birkhäuser Verlag, Basel, Switzerland, 2009

[3] Aleman, A.; Richter, S.; Sundberg, C. Beurling's theorem for the Bergman space, Acta Math., Volume 177 (1996), pp. 275-310

[4] Banach, S. Theory of Linear Operations, N.-Holl. Math. Libr., vol. 38, North-Holland Publishing Co., Amsterdam, 1987

[5] Bénéteau, C.; Condori, A.; Liaw, C.; Ross, W.T.; Sola, A. Some open problems in complex and harmonic analysis: report on problem session held during the conference Completeness problems, Carleson measures, and spaces of analytic functions, Recent Progress on Operator Theory and Approximation in Spaces of Analytic Functions, Contemp. Math., vol. 679, American Mathematical Society, Providence, RI, USA, 2016, pp. 207-217

[6] Cima, J.; Matheson, A.; Ross, W.T. The Cauchy Transform, Math. Surv. Monogr., vol. 125, American Mathematical Society, Providence, RI, USA, 2006

[7] El-Fallah, O.; Fricain, E.; Kellay, K.; Mashreghi, J.; Ransford, T. Constructive approximation in de Branges–Rovnyak spaces, Constr. Approx., Volume 44 (2016), pp. 269-281

[8] Havin, V.P.; Jöricke, B. The Uncertainty Principle in Harmonic Analysis, Encyclopaedia Math. Sci., vol. 72, Springer, Berlin, 1995

[9] Sarason, D. Sub-Hardy Hilbert Spaces in the Unit Disk, Univ. Arkansas Lect. Notes Math. Sci., vol. 10, John Wiley & Sons, Inc., New York, 1994

[10] Vinogradov, S.A. Properties of multipliers of integrals of Cauchy–Stieltjes type, and some problems of factorization of analytic functions, Drogobych, 1974, Volume 115 (1976), pp. 5-39 (in Russian); English translation in Transl. Amer. Math. Soc. (2), 1980, pp. 1-32

Cité par Sources :